)]}'
{
  "log": [
    {
      "commit": "1efe8fe1c2240acc476bed77740883df63373862",
      "tree": "9aab2376b46432d721cdb7cf6f3be992a8951c0c",
      "parents": [
        "bcf4dd43424cdfd8195f3955300a579fe58e9911"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Tue Feb 02 20:45:46 2010 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Feb 02 20:46:10 2010 +0100"
      },
      "message": "cfq-iosched: Do not idle on async queues\n\nFew weeks back, Shaohua Li had posted similar patch. I am reposting it\nwith more test results.\n\nThis patch does two things.\n\n- Do not idle on async queues.\n\n- It also changes the write queue depth CFQ drives (cfq_may_dispatch()).\n  Currently, we seem to driving queue depth of 1 always for WRITES. This is\n  true even if there is only one write queue in the system and all the logic\n  of infinite queue depth in case of single busy queue as well as slowly\n  increasing queue depth based on last delayed sync request does not seem to\n  be kicking in at all.\n\nThis patch will allow deeper WRITE queue depths (subjected to the other\nWRITE queue depth contstraints like cfq_quantum and last delayed sync\nrequest).\n\nShaohua Li had reported getting more out of his SSD. For me, I have got\none Lun exported from an HP EVA and when pure buffered writes are on, I\ncan get more out of the system. Following are test results of pure\nbuffered writes (with end_fsync\u003d1) with vanilla and patched kernel. These\nresults are average of 3 sets of run with increasing number of threads.\n\nAVERAGE[bufwfs][vanilla]\n-------\njob       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)\n---       --- --  ------------   -----------    -------------  -----------\nbufwfs    3   1   0              0              95349          474141\nbufwfs    3   2   0              0              100282         806926\nbufwfs    3   4   0              0              109989         2.7301e+06\nbufwfs    3   8   0              0              116642         3762231\nbufwfs    3   16  0              0              118230         6902970\n\nAVERAGE[bufwfs] [patched kernel]\n-------\nbufwfs    3   1   0              0              270722         404352\nbufwfs    3   2   0              0              206770         1.06552e+06\nbufwfs    3   4   0              0              195277         1.62283e+06\nbufwfs    3   8   0              0              260960         2.62979e+06\nbufwfs    3   16  0              0              299260         1.70731e+06\n\nI also ran buffered writes along with some sequential reads and some\nbuffered reads going on in the system on a SATA disk because the potential\nrisk could be that we should not be driving queue depth higher in presence\nof sync IO going to keep the max clat low.\n\nWith some random and sequential reads going on in the system on one SATA\ndisk I did not see any significant increase in max clat. So it looks like\nother WRITE queue depth control logic is doing its job. Here are the\nresults.\n\nAVERAGE[brr, bsr, bufw together] [vanilla]\n-------\njob       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)\n---       --- --  ------------   -----------    -------------  -----------\nbrr       3   1   850            546345         0              0\nbsr       3   1   14650          729543         0              0\nbufw      3   1   0              0              23908          8274517\n\nbrr       3   2   981.333        579395         0              0\nbsr       3   2   14149.7        1175689        0              0\nbufw      3   2   0              0              21921          1.28108e+07\n\nbrr       3   4   898.333        1.75527e+06    0              0\nbsr       3   4   12230.7        1.40072e+06    0              0\nbufw      3   4   0              0              19722.3        2.4901e+07\n\nbrr       3   8   900            3160594        0              0\nbsr       3   8   9282.33        1.91314e+06    0              0\nbufw      3   8   0              0              18789.3        23890622\n\nAVERAGE[brr, bsr, bufw mixed] [patched kernel]\n-------\njob       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)\n---       --- --  ------------   -----------    -------------  -----------\nbrr       3   1   837            417973         0              0\nbsr       3   1   14357.7        591275         0              0\nbufw      3   1   0              0              24869.7        8910662\n\nbrr       3   2   1038.33        543434         0              0\nbsr       3   2   13351.3        1205858        0              0\nbufw      3   2   0              0              18626.3        13280370\n\nbrr       3   4   913            1.86861e+06    0              0\nbsr       3   4   12652.3        1430974        0              0\nbufw      3   4   0              0              15343.3        2.81305e+07\n\nbrr       3   8   890            2.92695e+06    0              0\nbsr       3   8   9635.33        1.90244e+06    0              0\nbufw      3   8   0              0              17200.3        24424392\n\nSo looks like it might make sense to include this patch.\n\nThanks\nVivek\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "875feb63b9567442be73efbcc9a8470e376d6423",
      "tree": "554331e9634a5327daa755bb1b3338697866018b",
      "parents": [
        "7af92f8754b87bc78cbfd447d5f4096b25c46682"
      ],
      "author": {
        "name": "Divyesh Shah",
        "email": "dpshah@google.com",
        "time": "Wed Jan 06 18:58:20 2010 -0800"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Jan 11 16:16:18 2010 +0100"
      },
      "message": "cfq-iosched: Respect ioprio_class when preempting\n\nIn cfq_should_preempt(), we currently allow some cases where a non-RT request\ncan preempt an ongoing RT cfqq timeslice. This should not happen.\nExamples include:\n\no A sync_noidle wl type non-RT request pre-empting a sync_noidle wl type cfqq\n  on which we are idling.\no Once we have per-cgroup async queues, a non-RT sync request pre-empting a RT\n  async cfqq.\n\nSigned-off-by: Divyesh Shah\u003cdpshah@google.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "2f7a2d89a8b5915d89ad9ebeb0065db7d5831cea",
      "tree": "776c4a7e47b07437c30411d7324b5a1c7de01696",
      "parents": [
        "6ec1480d8539c8e2e6ba7fbbeffe5adc640bfe98"
      ],
      "author": {
        "name": "Shaohua Li",
        "email": "shaohua.li@intel.com",
        "time": "Mon Dec 28 13:18:44 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Dec 28 13:18:44 2009 +0100"
      },
      "message": "cfq-iosched: don\u0027t regard requests with long distance as close\n\nseek_mean could be very big sometimes, using it as close criteria is meaningless\nas this doen\u0027t improve any performance. So if it\u0027s big, let\u0027s fallback to\ndefault value.\n\nReviewed-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Shaohua Li\u003cshaohua.li@intel.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "65b32a573eefa1cdd3cbe5ea59326308e6c3b9ad",
      "tree": "bdcca029d184056ffc9eab0a9c0b95cdf123c9fb",
      "parents": [
        "fb104db41e6e006c85ce1097f372cd1e10c1755c"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Wed Dec 16 17:52:59 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 18 12:40:21 2009 +0100"
      },
      "message": "cfq-iosched: Remove prio_change logic for workload selection\n\no CFQ now internally divides cfq queues in therr workload categories. sync-idle,\n  sync-noidle and async. Which workload to run depends primarily on rb_key\n  offset across three service trees. Which is a combination of mulitiple things\n  including what time queue got queued on the service tree.\n\n  There is one exception though. That is if we switched the prio class, say\n  we served some RT tasks and again started serving BE class, then with-in\n  BE class we always started with sync-noidle workload irrespective of rb_key\n  offset in service trees.\n\n  This can provide better latencies for sync-noidle workload in the presence\n  of RT tasks.\n\no This patch gets rid of that exception and which workload to run with-in\n  class always depends on lowest rb_key across service trees. The reason\n  being that now we have multiple BE class groups and if we always switch\n  to sync-noidle workload with-in group, we can potentially starve a sync-idle\n  workload with-in group. Same is true for async workload which will be in\n  root group. Also the workload-switching with-in group will become very\n  unpredictable as it now depends whether some RT workload was running in\n  the system or not.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nReviewed-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nAcked-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "fb104db41e6e006c85ce1097f372cd1e10c1755c",
      "tree": "b769fd161d325f959e3c2c36116c5eb2f0e29f00",
      "parents": [
        "1db32c40600437c5e049796bd32f49f61244c6ef"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Wed Dec 16 17:52:58 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 18 12:40:21 2009 +0100"
      },
      "message": "cfq-iosched: Get rid of nr_groups\n\no Currently code does not seem to be using cfqd-\u003enr_groups. Get rid of it.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nReviewed-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1db32c40600437c5e049796bd32f49f61244c6ef",
      "tree": "09f72cf149d7d9034bc3cbcf9597e413c081c5d3",
      "parents": [
        "4a63b030d75a063b910b2bab014d84837cb33eb7"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Wed Dec 16 17:52:57 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 18 12:40:21 2009 +0100"
      },
      "message": "cfq-iosched: Remove the check for same cfq group from allow_merge\n\no allow_merge() already checks if submitting task is pointing to same cfqq\n  as rq has been queued in. If everything is fine, we should not be having\n  a task in one cgroup and having a pointer to cfqq in other cgroup.\n\n  Well I guess in some situations it can happen and that is, when a random\n  IO queue has been moved into root cgroup for group_isolation\u003d0. In\n  this case, tasks\u0027s cgroup/group is different from where actually cfqq is,\n  but this is intentional and in this case merging should be allowed.\n\n  The second situation is where due to close cooperator patches, multiple\n  processes can be sharing a cfqq. If everything implemented right, we should\n  not end up in a situation where tasks from different processes in different\n  groups are sharing the same cfqq as we allow merging of cooperating queues\n  only if they are in same group.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nReviewed-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "66ae291978177d5c012015f12b8fbc76dc7d0965",
      "tree": "1351d66beea2b0b2300a7491ca8d9ffb83578e34",
      "parents": [
        "82bbbf28db4beefcd8b897800153e21378270cd1"
      ],
      "author": {
        "name": "Gui Jianfeng",
        "email": "guijianfeng@cn.fujitsu.com",
        "time": "Tue Dec 15 10:08:45 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Dec 15 10:08:45 2009 +0100"
      },
      "message": "cfq: set workload as expired if it doesn\u0027t have any slice left\n\nWhen a group is resumed, if it doesn\u0027t have workload slice left,\nwe should set workload_expires as expired. Otherwise, we might\nstart from where we left in previous group by error.\nThanks the idea from Corrado.\n\nSigned-off-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "82bbbf28db4beefcd8b897800153e21378270cd1",
      "tree": "3e8a437711010c14d2e9e88dcf29afcfecf7ba9a",
      "parents": [
        "554554f60ad619e1efab01897208bc320b81d9da"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 10 19:25:41 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 10 19:25:41 2009 +0100"
      },
      "message": "Fix a CFQ crash in \"for-2.6.33\" branch of block tree\n\nI think my previous patch introduced a bug which can lead to CFQ hitting\nBUG_ON().\n\nThe offending commit in for-2.6.33 branch is.\n\ncommit 7667aa0630407bc07dc38dcc79d29cc0a65553c1\nAuthor: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nDate:   Tue Dec 8 17:52:58 2009 -0500\n\n    cfq-iosched: Take care of corner cases of group losing share due to deletion\n\nWhile doing some stress testing on my box, I enountered following.\n\nlogin: [ 3165.148841] BUG: scheduling while\natomic: swapper/0/0x10000100\n[ 3165.149821] Modules linked in: cfq_iosched dm_multipath qla2xxx igb\nscsi_transport_fc dm_snapshot [last unloaded: scsi_wait_scan]\n[ 3165.149821] Pid: 0, comm: swapper Not tainted\n2.6.32-block-for-33-merged-new #3\n[ 3165.149821] Call Trace:\n[ 3165.149821]  \u003cIRQ\u003e  [\u003cffffffff8103fab8\u003e] __schedule_bug+0x5c/0x60\n[ 3165.149821]  [\u003cffffffff8103afd7\u003e] ? __wake_up+0x44/0x4d\n[ 3165.149821]  [\u003cffffffff8153a979\u003e] schedule+0xe3/0x7bc\n[ 3165.149821]  [\u003cffffffff8103a796\u003e] ? cpumask_next+0x1d/0x1f\n[ 3165.149821]  [\u003cffffffffa000b21d\u003e] ? cfq_dispatch_requests+0x6ba/0x93e\n[cfq_iosched]\n[ 3165.149821]  [\u003cffffffff810422d8\u003e] __cond_resched+0x2a/0x35\n[ 3165.149821]  [\u003cffffffffa000b21d\u003e] ? cfq_dispatch_requests+0x6ba/0x93e\n[cfq_iosched]\n[ 3165.149821]  [\u003cffffffff8153b1ee\u003e] _cond_resched+0x2c/0x37\n[ 3165.149821]  [\u003cffffffff8100e2db\u003e] is_valid_bugaddr+0x16/0x2f\n[ 3165.149821]  [\u003cffffffff811e4161\u003e] report_bug+0x18/0xac\n[ 3165.149821]  [\u003cffffffff8100f1fc\u003e] die+0x39/0x63\n[ 3165.149821]  [\u003cffffffff8153cde1\u003e] do_trap+0x11a/0x129\n[ 3165.149821]  [\u003cffffffff8100d470\u003e] do_invalid_op+0x96/0x9f\n[ 3165.149821]  [\u003cffffffffa000b21d\u003e] ? cfq_dispatch_requests+0x6ba/0x93e\n[cfq_iosched]\n[ 3165.149821]  [\u003cffffffff81034b4d\u003e] ? enqueue_task+0x5c/0x67\n[ 3165.149821]  [\u003cffffffff8103ae83\u003e] ? task_rq_unlock+0x11/0x13\n[ 3165.149821]  [\u003cffffffff81041aae\u003e] ? try_to_wake_up+0x292/0x2a4\n[ 3165.149821]  [\u003cffffffff8100c935\u003e] invalid_op+0x15/0x20\n[ 3165.149821]  [\u003cffffffffa000b21d\u003e] ? cfq_dispatch_requests+0x6ba/0x93e\n[cfq_iosched]\n[ 3165.149821]  [\u003cffffffff810df5a6\u003e] ? virt_to_head_page+0xe/0x2f\n[ 3165.149821]  [\u003cffffffff811d8c2a\u003e] blk_peek_request+0x191/0x1a7\n[ 3165.149821]  [\u003cffffffff811e5b8d\u003e] ? kobject_get+0x1a/0x21\n[ 3165.149821]  [\u003cffffffff812c8d4c\u003e] scsi_request_fn+0x82/0x3df\n[ 3165.149821]  [\u003cffffffff8110b2de\u003e] ? bio_fs_destructor+0x15/0x17\n[ 3165.149821]  [\u003cffffffff810df5a6\u003e] ? virt_to_head_page+0xe/0x2f\n[ 3165.149821]  [\u003cffffffff811d931f\u003e] __blk_run_queue+0x42/0x71\n[ 3165.149821]  [\u003cffffffff811d9403\u003e] blk_run_queue+0x26/0x3a\n[ 3165.149821]  [\u003cffffffff812c8761\u003e] scsi_run_queue+0x2de/0x375\n[ 3165.149821]  [\u003cffffffff812b60ac\u003e] ? put_device+0x17/0x19\n[ 3165.149821]  [\u003cffffffff812c92d7\u003e] scsi_next_command+0x3b/0x4b\n[ 3165.149821]  [\u003cffffffff812c9b9f\u003e] scsi_io_completion+0x1c9/0x3f5\n[ 3165.149821]  [\u003cffffffff812c3c36\u003e] scsi_finish_command+0xb5/0xbe\n\nI think I have hit following BUG_ON() in cfq_dispatch_request().\n\nBUG_ON(RB_EMPTY_ROOT(\u0026cfqq-\u003esort_list));\n\nPlease find attached the patch to fix it. I have done some stress testing\nwith it and have not seen it happening again.\n\no We should wait on a queue even after slice expiry only if it is empty. If\n  queue is not empty then continue to expire it.\n\no If we decide to keep the queue then make cfqq\u003dNULL. Otherwise select_queue()\n  will return a valid cfqq and cfq_dispatch_request() can hit following\n  BUG_ON().\n\n  BUG_ON(RB_EMPTY_ROOT(\u0026cfqq-\u003esort_list))\n\nReviewed-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "554554f60ad619e1efab01897208bc320b81d9da",
      "tree": "b240b0e65dc763c6c2f7b5661f59ad4bcb0385b3",
      "parents": [
        "edc71131c4dc6cc73e2a24aa0a7a79cfce738f12"
      ],
      "author": {
        "name": "Gui Jianfeng",
        "email": "guijianfeng@cn.fujitsu.com",
        "time": "Thu Dec 10 09:38:39 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 10 09:38:39 2009 +0100"
      },
      "message": "cfq: Remove wait_request flag when idle time is being deleted\n\nRemove wait_request flag when idle time is being deleted, otherwise\nit\u0027ll hit this path every time when a request is enqueued.\n\nSigned-off-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "edc71131c4dc6cc73e2a24aa0a7a79cfce738f12",
      "tree": "b568734b3f053be12f0dabcf2ceea1049537cea1",
      "parents": [
        "7667aa0630407bc07dc38dcc79d29cc0a65553c1"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Wed Dec 09 20:56:04 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Dec 09 20:56:04 2009 +0100"
      },
      "message": "cfq-iosched: commenting non-obvious initialization\n\nAdded a comment to explain the initialization of last_delayed_sync.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nAcked-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "7667aa0630407bc07dc38dcc79d29cc0a65553c1",
      "tree": "cd9007b2dfebec215d955952ea0f9914490bddaa",
      "parents": [
        "c244bb50a9baa2ec47a458bbafb36b5e559ed5fa"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Tue Dec 08 17:52:58 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Dec 09 15:11:04 2009 +0100"
      },
      "message": "cfq-iosched: Take care of corner cases of group losing share due to deletion\n\nIf there is a sequential reader running in a group, we wait for next request\nto come in that group after slice expiry and once new request is in, we expire\nthe queue. Otherwise we delete the group from service tree and group looses\nits fair share.\n\nSo far I was marking a queue as wait_busy if it had consumed its slice and\nit was last queue in the group. But this condition did not cover following\ntwo cases.\n\n1.If a request completed and slice has not expired yet. Next request comes\n  in and is dispatched to disk. Now select_queue() hits and slice has expired.\n  This group will be deleted. Because request is still in the disk, this queue\n  will never get a chance to wait_busy.\n\n2.If request completed and slice has not expired yet. Before next request\n  comes in (delay due to think time), select_queue() hits and expires the\n  queue hence group. This queue never got a chance to wait busy.\n\nGui was hitting the boundary condition 1 and not getting fairness numbers\nproportional to weight.\n\nThis patch puts the checks for above two conditions and improves the fairness\nnumbers for sequential workload on rotational media. Check in select_queue()\ntakes care of case 1 and additional check in should_wait_busy() takes care\nof case 2.\n\nReported-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "c244bb50a9baa2ec47a458bbafb36b5e559ed5fa",
      "tree": "946c9c87e21055ff371a05710c7a0bcf71bdcc18",
      "parents": [
        "b9d8f4c73b1af4cfd53f819bf84c2bce31232275"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Tue Dec 08 17:52:57 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Dec 09 15:11:03 2009 +0100"
      },
      "message": "cfq-iosched: Get rid of cfqq wait_busy_done flag\n\no Get rid of wait_busy_done flag. This flag only tells we were doing wait\n  busy on a queue and that queue got request so expire it. That information\n  can easily be obtained by (cfq_cfqq_wait_busy() \u0026\u0026 queue_is_not_empty). So\n  remove this flag and keep code simple.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b9d8f4c73b1af4cfd53f819bf84c2bce31232275",
      "tree": "2ae92bc6cabfd9d2308902c3ac92f04fe6fbf1fb",
      "parents": [
        "a3b8d92d25212c5b6534ae9b347ed2858de78336"
      ],
      "author": {
        "name": "Gui Jianfeng",
        "email": "guijianfeng@cn.fujitsu.com",
        "time": "Tue Dec 08 08:54:17 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Dec 09 15:11:03 2009 +0100"
      },
      "message": "cfq: Optimization for close cooperating queue searching\n\nIt doesn\u0027t make any sense to try to find out a close cooperating\nqueue if current cfqq is the only one in the group.\n\nSigned-off-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "573412b29586e58477adb70e022193a337763319",
      "tree": "757ebcc4da3ba7b8d8beb8e8e0ff6a4fe4428f52",
      "parents": [
        "2b876f95d03e226394b5d360c86127cbefaf614b"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Sun Dec 06 11:48:52 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "axboe@carl.(none)",
        "time": "Wed Dec 09 12:32:55 2009 +0100"
      },
      "message": "cfq-iosched: reduce write depth only if sync was delayed\n\nThe introduction of ramp-up formula for async queue depths has\nslowed down dirty page reclaim, by reducing async write performance.\nThis patch makes sure the formula kicks in only when sync request\nwas recently delayed.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "878eaddd05d251cefa9632c2b8046833c5eead66",
      "tree": "a5bf9b6c1856969ff7a7cd0d676ea2b419072103",
      "parents": [
        "accee7854b378a8ab5995d8f5dc5d8abc3b3d23a"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Mon Dec 07 19:37:15 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "axboe@carl.(none)",
        "time": "Mon Dec 07 19:37:15 2009 +0100"
      },
      "message": "cfq-iosched: Do not access cfqq after freeing it\n\nFix a crash during boot reported by Jeff Moyer. Fix the issue of accessing\ncfqq after freeing it.\n\nReported-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nReviewed-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003caxboe@carl.(none)\u003e\n"
    },
    {
      "commit": "bb729bc98c0f3e6a898d8730df3e2830bf68751a",
      "tree": "f2170f8f688a7c7f813168a6c8c757087934c094",
      "parents": [
        "846954b0a32f4ae953e082eabd178e7a98dd2efd"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sun Dec 06 09:54:19 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sun Dec 06 09:54:19 2009 +0100"
      },
      "message": "cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit\n\nAfter the merge of the IO controller patches, booting on my megaraid\nbox ran much slower. Vivek Goyal traced it down to megaraid discovery\ncreating tons of devices, each suffering a grace period when they later\nkill that queue (if no device is found).\n\nSo lets use call_rcu() to batch these deferred frees, instead of taking\nthe grace period hit for each one.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "3e2520668970aab5a764044a298e987aafc1f63d",
      "tree": "088ebf7c4576d597774c8c332bab590dc3a472d6",
      "parents": [
        "9d6a986c0b276085f7944cd8ad65f4f82aff7536"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Fri Dec 04 10:36:42 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 04 16:38:14 2009 +0100"
      },
      "message": "blkio: Implement dynamic io controlling policy registration\n\no One of the goals of block IO controller is that it should be able to\n  support mulitple io control policies, some of which be operational at\n  higher level in storage hierarchy.\n\no To begin with, we had one io controlling policy implemented by CFQ, and\n  I hard coded the CFQ functions called by blkio. This created issues when\n  CFQ is compiled as module.\n\no This patch implements a basic dynamic io controlling policy registration\n  functionality in blkio. This is similar to elevator functionality where\n  ioschedulers register the functions dynamically.\n\no Now in future, when more IO controlling policies are implemented, these\n  can dynakically register with block IO controller.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "9d6a986c0b276085f7944cd8ad65f4f82aff7536",
      "tree": "1e72c813f4346ee329d5d427e214d183af78934f",
      "parents": [
        "b69f2292063d2caf37ca9aec7d63ded203701bf3"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Fri Dec 04 10:36:41 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 04 16:38:14 2009 +0100"
      },
      "message": "blkio: Export some symbols from blkio as its user CFQ can be a module\n\no blkio controller is inside the kernel and cfq makes use of interfaces\n  exported by blkio. CFQ can be a module too, hence export symbols used\n  by CFQ.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "3c764b7a654668dd04905841d6024f7b6aa843a5",
      "tree": "68b7c611f5e98bab3c781ecc775a0ecf46c43b61",
      "parents": [
        "237e5bc4e51813e9d8ba9da0f63e7acc608882d7"
      ],
      "author": {
        "name": "Shaohua Li",
        "email": "shaohua.li@intel.com",
        "time": "Fri Dec 04 13:12:06 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 04 13:12:06 2009 +0100"
      },
      "message": "cfq-iosched: make nonrot check logic consistent\n\ncfq_arm_slice_timer() has logic to disable idle window for SSD device. The same\nthing should be done at cfq_select_queue() too, otherwise we will still see\nidle window. This makes the nonrot check logic consistent in cfq.\nTests in a intel SSD with low_latency knob close, below patch can triple disk\nthoughput for muti-thread sequential read.\n\nSigned-off-by: Shaohua Li \u003cshaohua.li@intel.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "f2eecb91522686edf8199947b77f435a4031d92f",
      "tree": "e584c9d81971fb741508c176d74ef51ff45a4bcc",
      "parents": [
        "2f5ea47712489a9d2d3cb832eb06062e4e64e0ec"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 04 10:06:35 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Dec 04 10:06:35 2009 +0100"
      },
      "message": "cfq-iosched: move IO controller declerations to a header file\n\nThey should not be declared inside some other file that\u0027s not related\nto CFQ.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "c04645e592d4dd60c58def40c913699d4c806727",
      "tree": "61e2b6fac3c9dd0f211c07f024fe5cb17ff5d3cf",
      "parents": [
        "ae30c286553c91c49af5cbc0265a05a6543d0c52"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:56 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:53 2009 +0100"
      },
      "message": "blkio: Wait on sync-noidle queue even if rq_noidle \u003d 1\n\no rq_noidle() is supposed to tell cfq that do not expect a request after this\n  one, hence don\u0027t idle. But this does not seem to work very well. For example\n  for direct random readers, rq_noidle \u003d 1 but there is next request coming\n  after this. Not idling, leads to a group not getting its share even if\n  group_isolation\u003d1.\n\no The right solution for this issue is to scan the higher layers and set\n  right flag (WRITE_SYNC or WRITE_ODIRECT). For the time being, this single\n  line fix helps. This should not have any significant impact when we are\n  not using cgroups. I will later figure out IO paths in higher layer and\n  fix it.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "ae30c286553c91c49af5cbc0265a05a6543d0c52",
      "tree": "1dcb055e156ca9190d0da5bccf32a3a166e12d52",
      "parents": [
        "f26bd1f0a3a31bc5e16d285f5e1b00a56abf6238"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:55 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:53 2009 +0100"
      },
      "message": "blkio: Implement group_isolation tunable\n\no If a group is running only a random reader, then it will not have enough\n  traffic to keep disk busy and we will reduce overall throughput. This\n  should result in better latencies for random reader though. If we don\u0027t\n  idle on random reader service tree, then this random reader will experience\n  large latencies if there are other groups present in system with sequential\n  readers running in these.\n\no One solution suggested by corrado is that by default keep the random readers\n  or sync-noidle workload in root group so that during one dispatch round\n  we idle only once on sync-noidle tree. This means that all the sync-idle\n  workload queues will be in their respective group and we will see service\n  differentiation in those but not on sync-noidle workload.\n\no Provide a tunable group_isolation. If set, this will make sure that even\n  sync-noidle queues go in their respective group and we wait on these. This\n  provides stronger isolation between groups but at the expense of throughput\n  if group does not have enough traffic to keep the disk busy.\n\no By default group_isolation \u003d 0\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "f26bd1f0a3a31bc5e16d285f5e1b00a56abf6238",
      "tree": "8e49302c146eacdd1cfbe78a6bd3aad2b81c3050",
      "parents": [
        "f75edf2dc828802d358393be80a6c89e919f8273"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:54 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:53 2009 +0100"
      },
      "message": "blkio: Determine async workload length based on total number of queues\n\no Async queues are not per group. Instead these are system wide and maintained\n  in root group. Hence their workload slice length should be calculated\n  based on total number of queues in the system and not just queues in the\n  root group.\n\no As root group\u0027s default weight is 1000, make sure to charge async queue\n  more in terms of vtime so that it does not get more time on disk because\n  root group has higher weight.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "f75edf2dc828802d358393be80a6c89e919f8273",
      "tree": "a3b2fb05298ea41ecc0fd7ad56e1218369f7f9fd",
      "parents": [
        "f8d461d692c341add957fb973fb5ee1f62039dc7"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:53 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:53 2009 +0100"
      },
      "message": "blkio: Wait for cfq queue to get backlogged if group is empty\n\no If a queue consumes its slice and then gets deleted from service tree, its\n  associated group will also get deleted from service tree if this was the\n  only queue in the group. That will make group loose its share.\n\no For the queues on which we have idling on and if these have used their\n  slice, wait a bit for these queues to get backlogged again and then\n  expire these queues so that group does not loose its share.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "f8d461d692c341add957fb973fb5ee1f62039dc7",
      "tree": "42c6cf987aa4d38b271a60d2b62e92c6c748cd69",
      "parents": [
        "24610333d578478d354144ab4709a203684afc5f"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:52 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:53 2009 +0100"
      },
      "message": "blkio: Propagate cgroup weight updation to cfq groups\n\no Propagate blkio cgroup weight updation to associated cfq groups.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "24610333d578478d354144ab4709a203684afc5f",
      "tree": "d258c695cfa320845212f71e8900af4d90538d6b",
      "parents": [
        "8682e1f15f26dae9a9e8af794d179055fbd81166"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:51 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Drop the reference to queue once the task changes cgroup\n\no If a task changes cgroup, drop reference to the cfqq associated with io\n  context and set cfqq pointer stored in ioc to NULL so that upon next request\n  arrival we will allocate a  new queue in new group.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "8682e1f15f26dae9a9e8af794d179055fbd81166",
      "tree": "d6e87631f91527656490df9b28be107fb5e974b0",
      "parents": [
        "220841906fccafaf4094e87bdb6d252e20cf8c7c"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:50 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Provide some isolation between groups\n\no Do not allow following three operations across groups for isolation.\n\t- selection of co-operating queues\n\t- preemtpions across groups\n\t- request merging across groups.\n\no Async queues are currently global and not per group. Allow preemption of\n  an async queue if a sync queue in other group gets backlogged.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "220841906fccafaf4094e87bdb6d252e20cf8c7c",
      "tree": "f25b1f057887cf2a05bb8309e0b757149e052797",
      "parents": [
        "2868ef7b39490e6b41c2c61cd9a5cd891e778b54"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:49 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Export disk time and sectors used by a group to user space\n\no Export disk time and sector used by a group to user space through cgroup\n  interface.\n\no Also export a \"dequeue\" interface to cgroup which keeps track of how many\n  a times a group was deleted from service tree. Helps in debugging.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "2868ef7b39490e6b41c2c61cd9a5cd891e778b54",
      "tree": "e50e169e984d8bd201de2f73f98e31a65c028feb",
      "parents": [
        "b1c3576961847da26c91b1e97f226bb66be5fa3f"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:48 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Some debugging aids for CFQ\n\no Some debugging aids for CFQ.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b1c3576961847da26c91b1e97f226bb66be5fa3f",
      "tree": "e228525220031232463f9cbbe017bad67807e6d4",
      "parents": [
        "25fb5169d4c9d4255107abbb7c08ab712434efc8"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:47 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Take care of cgroup deletion and cfq group reference counting\n\no One can choose to change elevator or delete a cgroup. Implement group\n  reference counting so that both elevator exit and cgroup deletion can\n  take place gracefully.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Nauman Rafique \u003cnauman@google.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "25fb5169d4c9d4255107abbb7c08ab712434efc8",
      "tree": "8939bd6f73f9888d954672dfaac1cc25e313cb2f",
      "parents": [
        "dae739ebc4c590630039533a5bbd05865966094f"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:46 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Dynamic cfq group creation based on cgroup tasks belongs to\n\no Determine the cgroup IO submitting task belongs to and create the cfq\n  group if it does not exist already.\n\no Also link cfqq and associated cfq group.\n\no Currently all async IO is mapped to root group.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "dae739ebc4c590630039533a5bbd05865966094f",
      "tree": "005f98ed4c4302ea71b48ad6a074fa6ff714df4a",
      "parents": [
        "58ff82f34cded3812af5b6c69b6aa626b6be2490"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:45 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Group time used accounting and workload context save restore\n\no This patch introduces the functionality to do the accounting of group time\n  when a queue expires. This time used decides which is the group to go\n  next.\n\no Also introduce the functionlity to save and restore the workload type\n  context with-in group. It might happen that once we expire the cfq queue\n  and group, a different group will schedule in and we will lose the context\n  of the workload type. Hence save and restore it upon queue expiry.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "58ff82f34cded3812af5b6c69b6aa626b6be2490",
      "tree": "06098474c5763f20d1c9715faf67c83c56b9a787",
      "parents": [
        "25bc6b07767fe77422312eda2af99c9477f76191"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:44 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Implement per cfq group latency target and busy queue avg\n\no So far we had 300ms soft target latency system wide. Now with the\n  introduction of cfq groups, divide that latency by number of groups so\n  that one can come up with group target latency which will be helpful\n  in determining the workload slice with-in group and also the dynamic\n  slice length of the cfq queue.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "25bc6b07767fe77422312eda2af99c9477f76191",
      "tree": "1e0f2d5a18efb63c651df8773a6d5ad2b87d7687",
      "parents": [
        "31e4c28d95e64f2d5d3c497a3ecf37c62de635b4"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:43 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:52 2009 +0100"
      },
      "message": "blkio: Introduce per cfq group weights and vdisktime calculations\n\no Bring in the per cfq group weight and how vdisktime is calculated for the\n  group. Also bring in the functionality of updating the min_vdisktime of\n  the group service tree.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1fa8f6d68b5c8ca0a608fd8d296c5f07ac788cd6",
      "tree": "1e6d9e0ed1bd61f7f8f71a7191815be2ab65aac3",
      "parents": [
        "f04a64246344ad50e4b4b4186174a0912d07f30b"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:41 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:51 2009 +0100"
      },
      "message": "blkio: Introduce the root service tree for cfq groups\n\no So far we just had one cfq_group in cfq_data. To create space for more than\n  one cfq_group, we need to have a service tree of groups where all the groups\n  can be queued if they have active cfq queues backlogged in these.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "f04a64246344ad50e4b4b4186174a0912d07f30b",
      "tree": "03d2d39d2811350af39dd635297b90ca52b9b6fe",
      "parents": [
        "615f0259e6940293359a189f4881bb28c2fea40b"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:40 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:51 2009 +0100"
      },
      "message": "blkio: Keep queue on service tree until we expire it\n\no Currently cfqq deletes a queue from service tree if it is empty (even if\n  we might idle on the queue). This patch keeps the queue on service tree\n  hence associated group remains on the service tree until we decide that\n  we are not going to idle on the queue and expire it.\n\no This just helps in time accounting for queue/group and in implementation\n  of rest of the patches.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "615f0259e6940293359a189f4881bb28c2fea40b",
      "tree": "36ae080bc809a8d998801c0bcfc0d63b7b892745",
      "parents": [
        "cdb16e8f739985b8a5c9f4569b026583bbcd01a5"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:39 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:51 2009 +0100"
      },
      "message": "blkio: Implement macro to traverse each service tree in group\n\no Implement a macro to traverse each service tree in the group. This avoids\n  usage of double for loop and special condition for idle tree 4 times.\n\no Macro is little twisted because of special handling of idle class service\n  tree.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "cdb16e8f739985b8a5c9f4569b026583bbcd01a5",
      "tree": "860b74f8134cfbd516cc73b8b9a9edfe4e3d2db6",
      "parents": [
        "bf7919371025412978268efca4b09dd847acb395"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:38 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:51 2009 +0100"
      },
      "message": "blkio: Introduce the notion of cfq groups\n\no This patch introduce the notion of cfq groups. Soon we will can have multiple\n  groups of different weights in the system.\n\no Various service trees (prioclass and workload type trees), will become per\n  cfq group. So hierarchy looks as follows.\n\n\t\t\tcfq_groups\n\t\t\t   |\n\t\t\tworkload type\n\t\t\t   |\n\t\t        cfq queue\n\no When an scheduling decision has to be taken, first we select the cfq group\n  then workload with-in the group and then cfq queue with-in the workload\n  type.\n\no This patch just makes various workload service tree per cfq group and\n  introduce the function to be able to choose a group for scheduling.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "bf7919371025412978268efca4b09dd847acb395",
      "tree": "f6144bf301f00f53f150f4213928f063232faaa1",
      "parents": [
        "753c89130c52b96e66e5ceff19bd1336de9a5ce8"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Dec 03 12:59:37 2009 -0500"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 19:28:51 2009 +0100"
      },
      "message": "blkio: Set must_dispatch only if we decided to not dispatch the request\n\no must_dispatch flag should be set only if we decided not to run the queue\n  and dispatch the request.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "474b18ccc264c472abeec50f48469b6477202699",
      "tree": "77c9f33d65b78266560b3aa0bea1c7d16fb45b2e",
      "parents": [
        "98262f2762f0067375f83824d81ea929e37e6bfe"
      ],
      "author": {
        "name": "Shaohua Li",
        "email": "shaohua.li@intel.com",
        "time": "Thu Dec 03 12:58:05 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Dec 03 12:58:05 2009 +0100"
      },
      "message": "cfq-iosched: no dispatch limit for single queue\n\nSince commit 2f5cb7381b737e24c8046fd4aeab571fb71315f5, each queue can send\nup to 4 * 4 requests if only one queue exists. I wonder why we have such limit.\nDevice supports tag can send more requests. For example, AHCI can send 31\nrequests. Test (direct aio randread) shows the limits reduce about 4% disk\nthoughput.\nOn the other hand, since we send one request one time, if other queue\npop when current is sending more than cfq_quantum requests, current queue will\nstop send requests soon after one request, so sounds there is no big latency.\n\nSigned-off-by: Shaohua Li \u003cshaohua.li@intel.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "464191c65b85a8ec68a6e1a6293af625287c807e",
      "tree": "4d4b91a3a4ce2faeb63758b119f0fb229fcc57ea",
      "parents": [
        "8e550632cccae34e265cb066691945515eaa7fb5"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Nov 30 09:38:13 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Nov 30 09:38:13 2009 +0100"
      },
      "message": "Revert \"cfq: Make use of service count to estimate the rb_key offset\"\n\nThis reverts commit 3586e917f2c7df769d173c4ec99554cb40a911e5.\n\nCorrado Zoccolo \u003cczoccolo@gmail.com\u003e correctly points out, that we need\nconsistency of rb_key offset across groups. This means we cannot properly\nuse the per-service_tree service count. Revert this change.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "8e550632cccae34e265cb066691945515eaa7fb5",
      "tree": "5aa4f97734b85076c1e743df143e63a9c12c294f",
      "parents": [
        "76280aff1c7e9ae761cac4b48591c43cd7d69159"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Nov 26 10:02:58 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 10:39:31 2009 +0100"
      },
      "message": "cfq-iosched: fix corner cases in idling logic\n\nIdling logic was disabled in some corner cases, leading to unfair share\n for noidle queues.\n * the idle timer was not armed if there were other requests in the\n   driver. unfortunately, those requests could come from other workloads,\n   or queues for which we don\u0027t enable idling. So we will check only\n   pending requests from the active queue\n * rq_noidle check on no-idle queue could disable the end of tree idle if\n   the last completed request was rq_noidle. Now, we will disable that\n   idle only if all the queues served in the no-idle tree had rq_noidle\n   requests.\n\nReported-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nAcked-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "76280aff1c7e9ae761cac4b48591c43cd7d69159",
      "tree": "f8b354746a96cf45a4d0fc980df4e37e3c37b173",
      "parents": [
        "e4a229196a7c676514c78f6783f8994f64bf681c"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Nov 26 10:02:58 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 10:39:31 2009 +0100"
      },
      "message": "cfq-iosched: idling on deep seeky sync queues\n\nSeeky sync queues with large depth can gain unfairly big share of disk\n time, at the expense of other seeky queues. This patch ensures that\n idling will be enabled for queues with I/O depth at least 4, and small\n think time. The decision to enable idling is sticky, until an idle\n window times out without seeing a new request.\n\nThe reasoning behind the decision is that, if an application is using\nlarge I/O depth, it is already optimized to make full utilization of\nthe hardware, and therefore we reserve a slice of exclusive use for it.\n\nReported-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e4a229196a7c676514c78f6783f8994f64bf681c",
      "tree": "b2a9e72f863cfaadaad697158969214cd8bb5681",
      "parents": [
        "e459dd08f45d2aa68abb0c02f8ab045cf8a598b8"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Nov 26 10:02:58 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 10:39:31 2009 +0100"
      },
      "message": "cfq-iosched: fix no-idle preemption logic\n\nAn incoming no-idle queue should preempt the active no-idle queue\n only if the active queue is idling due to service tree empty.\n Previous code was buggy in two ways:\n * it relied on service_tree field to be set on the active queue, while\n   it is not set when the code is idling for a new request\n * it didn\u0027t check for the service tree empty condition, so could lead to\n   LIFO behaviour if multiple queues with depth \u003e 1 were preempting each\n   other on an non-NCQ device.\n\nReported-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nAcked-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e459dd08f45d2aa68abb0c02f8ab045cf8a598b8",
      "tree": "e5bba2c95dbbd93d2880fdc81e1ea7589625a6ed",
      "parents": [
        "75e7b634309ef4eabf8a93d36e58863f727fa209"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Nov 26 10:02:57 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 10:02:57 2009 +0100"
      },
      "message": "cfq-iosched: fix ncq detection code\n\nCFQ\u0027s detection of queueing devices initially assumes a queuing device\nand detects if the queue depth reaches a certain threshold.\nHowever, it will reconsider this choice periodically.\n\nUnfortunately, if device is considered not queuing, CFQ will force a\nunit queue depth for some workloads, thus defeating the detection logic.\nThis leads to poor performance on queuing hardware,\nsince the idle window remains enabled.\n\nGiven this premise, switching to hw_tag \u003d 0 after we have proved at\nleast once that the device is NCQ capable is not a good choice.\n\nThe new detection code starts in an indeterminate state, in which CFQ behaves\nas if hw_tag \u003d 1, and then, if for a long observation period we never saw\nlarge depth, we switch to hw_tag \u003d 0, otherwise we stick to hw_tag \u003d 1,\nwithout reconsidering it again.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "c16632bab1a17e357cec66920ceb3f0630009360",
      "tree": "6937755404314252f0bf2c46eec374c32c12f8b1",
      "parents": [
        "2d4dc890b5c8fabd818a8586607e6843c4375e62"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Nov 26 09:41:21 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 09:46:46 2009 +0100"
      },
      "message": "cfq-iosched: cleanup unreachable code\n\ncfq_should_idle returns false for no-idle queues that are not the last,\nso the control flow will never reach the removed code in a state that\nsatisfies the if condition.\nThe unreachable code was added to emulate previous cfq behaviour for\nnon-NCQ rotational devices. My tests show that even without it, the\nperformances and fairness are comparable with previous cfq, thanks to\nthe fact that all seeky queues are grouped together, and that we idle at\nthe end of the tree.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nAcked-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "3586e917f2c7df769d173c4ec99554cb40a911e5",
      "tree": "d72ad5ca6c17a3db628734e36b22d79065e0eb49",
      "parents": [
        "32a87c0114f37871aefb12a30de3e0c3300e3646"
      ],
      "author": {
        "name": "Gui Jianfeng",
        "email": "guijianfeng@cn.fujitsu.com",
        "time": "Thu Nov 26 09:14:11 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Nov 26 09:14:11 2009 +0100"
      },
      "message": "cfq: Make use of service count to estimate the rb_key offset\n\nFor the moment, different workload cfq queues are put into different\nservice trees. But CFQ still uses \"busy_queues\" to estimate rb_key\noffset when inserting a cfq queue into a service tree. I think this\nisn\u0027t appropriate, and it should make use of service tree count to do\nthis estimation. This patch is for for-2.6.33 branch.\n\nSigned-off-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "ad5ebd2fa2557b04a653bb3c3377a47da8f9b8e9",
      "tree": "f70ba006e73db3450b468c3098d43fc2a392b1da",
      "parents": [
        "86b37281411cf1e9bc0a6b5406c45edb7bd9ea5d"
      ],
      "author": {
        "name": "Randy Dunlap",
        "email": "randy.dunlap@oracle.com",
        "time": "Wed Nov 11 13:47:45 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Nov 11 13:47:45 2009 +0100"
      },
      "message": "block: jiffies fixes\n\nUse HZ-independent calculation of milliseconds.\nAdd jiffies.h where it was missing since functions or macros\nfrom it are used.\n\nSigned-off-by: Randy Dunlap \u003crandy.dunlap@oracle.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "cf7c25cf91f632a3528669fc0876e1fc8355ff9b",
      "tree": "7967e65544dd49cb7333363ec928722a9e4a1562",
      "parents": [
        "622d32d3ec40d5075523656ef0ea836f6a595ae3"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Sun Nov 08 17:16:46 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sun Nov 08 17:16:46 2009 +0100"
      },
      "message": "cfq-iosched: fix next_rq computation\n\nCfq has a bug in computation of next_rq, that affects transition\nbetween multiple sequential request streams in a single queue\n(e.g.: two sequential buffered writers of the same priority),\ncausing the alternation between the two streams for a transient period.\n\n  8,0    1    18737     0.260400660  5312  D   W 141653311 + 256\n  8,0    1    20839     0.273239461  5400  D   W 141653567 + 256\n  8,0    1    20841     0.276343885  5394  D   W 142803919 + 256\n  8,0    1    20843     0.279490878  5394  D   W 141668927 + 256\n  8,0    1    20845     0.292459993  5400  D   W 142804175 + 256\n  8,0    1    20847     0.295537247  5400  D   W 141668671 + 256\n  8,0    1    20849     0.298656337  5400  D   W 142804431 + 256\n  8,0    1    20851     0.311481148  5394  D   W 141668415 + 256\n  8,0    1    20853     0.314421305  5394  D   W 142804687 + 256\n  8,0    1    20855     0.318960112  5400  D   W 142804943 + 256\n\nThe fix makes sure that the next_rq is computed from the last\ndispatched request, and not affected by merging.\n\n  8,0    1    37776     4.305161306     0  D   W 141738087 + 256\n  8,0    1    37778     4.308298091     0  D   W 141738343 + 256\n  8,0    1    37780     4.312885190     0  D   W 141738599 + 256\n  8,0    1    37782     4.315933291     0  D   W 141738855 + 256\n  8,0    1    37784     4.319064459     0  D   W 141739111 + 256\n  8,0    1    37786     4.331918431  5672  D   W 142803007 + 256\n  8,0    1    37788     4.334930332  5672  D   W 142803263 + 256\n  8,0    1    37790     4.337902723  5672  D   W 142803519 + 256\n  8,0    1    37792     4.342359774  5672  D   W 142803775 + 256\n  8,0    1    37794     4.345318286     0  D   W 142804031 + 256\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e00ef7997195e4f8e10593727a6286e2e2802159",
      "tree": "51f73547c081f9068296c0c166599e5fbe340c9c",
      "parents": [
        "125c4f221a5352ae08aef2898055b879ad963f01"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Nov 04 08:54:55 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Nov 04 08:54:55 2009 +0100"
      },
      "message": "cfq-iosched: get rid of the coop_preempt flag\n\nWe need to rework this logic post the cooperating cfq_queue merging,\nfor now just get rid of it and Jeff Moyer will fix the fall out.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "125c4f221a5352ae08aef2898055b879ad963f01",
      "tree": "3114b880f0da09535d164923698a7e8d0b700e54",
      "parents": [
        "2058297d2d045cb57138c33b87cfabcc80e65186"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:25:45 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:25:45 2009 +0100"
      },
      "message": "cfq-iosched: fix merge error\n\nWe ended up with testing the same condition twice, pretty\npointless. Remove that first if.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "2058297d2d045cb57138c33b87cfabcc80e65186",
      "tree": "7ccffd0e162cbd7471f643561e79f23abb989a62",
      "parents": [
        "150e6c67f4bf6ab51e62defc41bd19a2eefe5709",
        "4b27e1bb442e964903f8a3fa6bdf33a602dc0941"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:14:39 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:14:39 2009 +0100"
      },
      "message": "Merge branch \u0027for-linus\u0027 into for-2.6.33\n\nConflicts:\n\tblock/cfq-iosched.c\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "150e6c67f4bf6ab51e62defc41bd19a2eefe5709",
      "tree": "586bd5450afc4f142d78017389af260e76c19f0b",
      "parents": [
        "4f570f995f68ef77aae7e5a441222f59232f2d0e",
        "5869619cb5b26754574375472fe54a390edf34c7"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:12:10 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 21:12:10 2009 +0100"
      },
      "message": "Merge branch \u0027cfq-2.6.33\u0027 into for-2.6.33\n"
    },
    {
      "commit": "4b27e1bb442e964903f8a3fa6bdf33a602dc0941",
      "tree": "d7eecb66f6a75dbff292fbd03b643b04ed075289",
      "parents": [
        "e6ec4fe24572ee265723d895ec4159e5559c8266"
      ],
      "author": {
        "name": "Shaohua Li",
        "email": "shaohua.li@intel.com",
        "time": "Tue Nov 03 20:25:02 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 20:25:02 2009 +0100"
      },
      "message": "cfq-iosched: limit coop preemption\n\nCFQ has an optimization for cooperated applications. if several\nio-context have close requests, they will get boost. But the\noptimization get abused. Considering thread a, b, which work on one\nfile. a reads sectors s, s+2, s+4, ...; b reads sectors s+1, s+3, s\n+5, ... Both a and b are sequential read, so they can open idle window.\na reads a sector s and goes to idle window and wakeup b. b reads sector\ns+1, since in current implementation, cfq_should_preempt() thinks a and\nb are cooperators, b will preempt a. b then reads sector s+1 and goes to\nidle window and wakeup a. for the same reason, a will preempt b and\nreads s+2. a and b will continue the circle. The circle will be very\nlong, and a and b will occupy whole disk queue. Other applications will\nnearly have no chance to run.\n\nFix this limiting coop preempt until a queue is scheduled normally\nagain.\n\nSigned-off-by: Shaohua Li \u003cshaohua.li@intel.com\u003e\nAcked-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e6ec4fe24572ee265723d895ec4159e5559c8266",
      "tree": "cf61a73b2e50d695579cffe4226d41da5c889f8f",
      "parents": [
        "8c4db3355b0fcc9ad77431f15b955efa0645b5d0"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 20:21:35 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Nov 03 20:21:35 2009 +0100"
      },
      "message": "cfq-iosched: fix bad return value cfq_should_preempt()\n\nCommit a6151c3a5c8e1ff5a28450bc8d6a99a2a0add0a7 inadvertently reversed\na preempt condition check, potentially causing a performance regression.\nMake the meta check correct again.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "dddb74519aec2081204d203a97578c9fc4e9fb64",
      "tree": "8737fb08028c1d0bbf01775704a7dc41501bbf71",
      "parents": [
        "ab0a9735e06914ce4d2a94ffa41497dbc142fe7f"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Nov 02 10:40:37 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Nov 02 10:40:37 2009 +0100"
      },
      "message": "cfq-iosched: simplify prio-unboost code\n\nEliminate redundant checks.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "5869619cb5b26754574375472fe54a390edf34c7",
      "tree": "20e0b9852aea2a4ede1b76d0f3672233b31e2399",
      "parents": [
        "718eee0579b802aabe3bafacf09d0a9b0830f1dd"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:27:07 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:27:07 2009 +0100"
      },
      "message": "cfq-iosched: fix style issue in cfq_get_avg_queues()\n\nLine breaks and bad brace placement.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "718eee0579b802aabe3bafacf09d0a9b0830f1dd",
      "tree": "3a85a6d38ed7b68ed6ca21d04158afee13980e5e",
      "parents": [
        "a6d44e982d3734583b3b4e1d36921af8cfd61fc0"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Oct 26 22:45:29 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:23:26 2009 +0100"
      },
      "message": "cfq-iosched: fairness for sync no-idle queues\n\nCurrently no-idle queues in cfq are not serviced fairly:\neven if they can only dispatch a small number of requests at a time,\nthey have to compete with idling queues to be serviced, experiencing\nlarge latencies.\n\nWe should notice, instead, that no-idle queues are the ones that would\nbenefit most from having low latency, in fact they are any of:\n* processes with large think times (e.g. interactive ones like file\n  managers)\n* seeky (e.g. programs faulting in their code at startup)\n* or marked as no-idle from upper levels, to improve latencies of those\n  requests.\n\nThis patch improves the fairness and latency for those queues, by:\n* separating sync idle, sync no-idle and async queues in separate\n  service_trees, for each priority\n* service all no-idle queues together\n* and idling when the last no-idle queue has been serviced, to\n  anticipate for more no-idle work\n* the timeslices allotted for idle and no-idle service_trees are\n  computed proportionally to the number of processes in each set.\n\nServicing all no-idle queues together should have a performance boost\nfor NCQ-capable drives, without compromising fairness.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "a6d44e982d3734583b3b4e1d36921af8cfd61fc0",
      "tree": "1d9b409057361524af2e097fe5de1c505533d603",
      "parents": [
        "c0324a020e5b351f100569b128715985f1023af8"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Oct 26 22:45:11 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:23:26 2009 +0100"
      },
      "message": "cfq-iosched: enable idling for last queue on priority class\n\ncfq can disable idling for queues in various circumstances.\nWhen workloads of different priorities are competing, if the higher\npriority queue has idling disabled, lower priority queues may steal\nits disk share. For example, in a scenario with an RT process\nperforming seeky reads vs a BE process performing sequential reads,\non an NCQ enabled hardware, with low_latency unset,\nthe RT process will dispatch only the few pending requests every full\nslice of service for the BE process.\n\nThe patch solves this issue by always performing idle on the last\nqueue at a given priority class \u003e idle. If the same process, or one\nthat can pre-empt it (so at the same priority or higher), submits a\nnew request within the idle window, the lower priority queue won\u0027t\ndispatch, saving the disk bandwidth for higher priority ones.\n\nNote: this doesn\u0027t touch the non_rotational + NCQ case (no hardware\nto test if this is a benefit in that case).\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "c0324a020e5b351f100569b128715985f1023af8",
      "tree": "56d99ec857349fa07dd9ddfdacfa091c7c11af44",
      "parents": [
        "aa6f6a3de18131348f70951efb2c56d806033e09"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Tue Oct 27 19:16:03 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:23:26 2009 +0100"
      },
      "message": "cfq-iosched: reimplement priorities using different service trees\n\nWe use different service trees for different priority classes.\nThis allows a simplification in the service tree insertion code, that no\nlonger has to consider priority while walking the tree.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "aa6f6a3de18131348f70951efb2c56d806033e09",
      "tree": "3565b2f9d2390d4ec054f32658461e781f106997",
      "parents": [
        "5db5d64277bf390056b1a87d0bb288c8b8553f96"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Oct 26 22:44:33 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:23:26 2009 +0100"
      },
      "message": "cfq-iosched: preparation to handle multiple service trees\n\nWe embed a pointer to the service tree in each queue, to handle multiple\nservice trees easily.\nService trees are enriched with a counter.\ncfq_add_rq_rb is invoked after putting the rq in the fifo, to ensure\nthat all fields in rq are properly initialized.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "5db5d64277bf390056b1a87d0bb288c8b8553f96",
      "tree": "eced8cdeae49e6920bbb9ae18b33ed7001332233",
      "parents": [
        "1a1238a7dd48e48b3bba8f426a1d61c22c80d6d1"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Oct 26 22:44:04 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 28 09:23:26 2009 +0100"
      },
      "message": "cfq-iosched: adapt slice to number of processes doing I/O\n\nWhen the number of processes performing I/O concurrently increases,\na fixed time slice per process will cause large latencies.\n\nThis patch, if low_latency mode is enabled,  will scale the time slice\nassigned to each process according to a 300ms target latency.\n\nIn order to keep fairness among processes:\n* The number of active processes is computed using a special form of\nrunning average, that quickly follows sudden increases (to keep latency low),\nand decrease slowly (to have fairness in spite of rapid decreases of this\nvalue).\n\nTo safeguard sequential bandwidth, we impose a minimum time slice\n(computed using 2*cfq_slice_idle as base, adjusted according to priority\nand async-ness).\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1a1238a7dd48e48b3bba8f426a1d61c22c80d6d1",
      "tree": "08a39610689b5da8e8d61701864b8eb257acd6d7",
      "parents": [
        "e6c5bc737ab71e4af6025ef7d150f5a26ae5f146"
      ],
      "author": {
        "name": "Shaohua Li",
        "email": "shaohua.li@intel.com",
        "time": "Tue Oct 27 08:46:23 2009 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Oct 27 08:46:23 2009 +0100"
      },
      "message": "cfq-iosched: improve hw_tag detection\n\nIf active queue hasn\u0027t enough requests and idle window opens, cfq will not\ndispatch sufficient requests to hardware. In such situation, current code\nwill zero hw_tag. But this is because cfq doesn\u0027t dispatch enough requests\ninstead of hardware queue doesn\u0027t work. Don\u0027t zero hw_tag in such case.\n\nSigned-off-by: Shaohua Li \u003cshaohua.li@intel.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e6c5bc737ab71e4af6025ef7d150f5a26ae5f146",
      "tree": "01127225a83bdcae30b261b9f21bb89faa7db8ce",
      "parents": [
        "b3b6d0408c953524f979468562e7e210d8634150"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Oct 23 17:14:52 2009 -0400"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 26 14:34:47 2009 +0100"
      },
      "message": "cfq: break apart merged cfqqs if they stop cooperating\n\ncfq_queues are merged if they are issuing requests within the mean seek\ndistance of one another.  This patch detects when the coopearting stops and\nbreaks the queues back up.\n\nSigned-off-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b3b6d0408c953524f979468562e7e210d8634150",
      "tree": "1556cb393f2edc09e64c8961f6792cbb79b4e288",
      "parents": [
        "df5fe3e8e13883f58dc97489076bbcc150789a21"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Oct 23 17:14:51 2009 -0400"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 26 14:34:47 2009 +0100"
      },
      "message": "cfq: change the meaning of the cfqq_coop flag\n\nThe flag used to indicate that a cfqq was allowed to jump ahead in the\nscheduling order due to submitting a request close to the queue that\njust executed.  Since closely cooperating queues are now merged, the flag\nholds little meaning.  Change it to indicate that multiple queues were\nmerged.  This will later be used to allow the breaking up of merged queues\nwhen they are no longer cooperating.\n\nSigned-off-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "df5fe3e8e13883f58dc97489076bbcc150789a21",
      "tree": "b05ce6760cd2b52e42dca22e3659a0255f4a4e4a",
      "parents": [
        "b2c18e1e08a5a9663094d57bb4be2f02226ee61c"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Oct 23 17:14:50 2009 -0400"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 26 14:34:47 2009 +0100"
      },
      "message": "cfq: merge cooperating cfq_queues\n\nWhen cooperating cfq_queues are detected currently, they are allowed to\nskip ahead in the scheduling order.  It is much more efficient to\nautomatically share the cfq_queue data structure between cooperating processes.\nPerformance of the read-test2 benchmark (which is written to emulate the\ndump(8) utility) went from 12MB/s to 90MB/s on my SATA disk.  NFS servers\nwith multiple nfsd threads also saw performance increases.\n\nSigned-off-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b2c18e1e08a5a9663094d57bb4be2f02226ee61c",
      "tree": "55c092706a0d8a9e645f245bf2ecc45c29ba5aa7",
      "parents": [
        "c30f33437c3f85ec48353a1ef811e148217a2aaf"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Oct 23 17:14:49 2009 -0400"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 26 14:34:46 2009 +0100"
      },
      "message": "cfq: calculate the seek_mean per cfq_queue not per cfq_io_context\n\nasync cfq_queue\u0027s are already shared between processes within the same\npriority, and forthcoming patches will change the mapping of cic to sync\ncfq_queue from 1:1 to 1:N.  So, calculate the seekiness of a process\nbased on the cfq_queue instead of the cfq_io_context.\n\nSigned-off-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "355b659c87432a4e76160640625c47fcf9174e8d",
      "tree": "1121f7c4ae13643a30abaf6091312f5b116a52bc",
      "parents": [
        "a6151c3a5c8e1ff5a28450bc8d6a99a2a0add0a7"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Thu Oct 08 08:43:32 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Oct 08 08:43:32 2009 +0200"
      },
      "message": "cfq-iosched: avoid probable slice overrun when idling\n\nIf the average think time is larger than the remaining time slice\nfor any given queue, don\u0027t allow it to idle. A succesful idle also\nmeans that we need to dispatch and complete a request, so if we don\u0027t\neven have time left for the idle process, we would overrun the slice\nin any case.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "a6151c3a5c8e1ff5a28450bc8d6a99a2a0add0a7",
      "tree": "47896def7d76c1f81d3c358a9aaee158a253b2b6",
      "parents": [
        "ec60e4f6749daf535329dac571293cf19c627aff"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 07 20:02:57 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 07 20:02:57 2009 +0200"
      },
      "message": "cfq-iosched: apply bool value where we return 0/1\n\nSaves 16 bytes of text, woohoo. But the more important point is\nthat it makes the code more readable when returning bool for 0/1\ncases.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "ec60e4f6749daf535329dac571293cf19c627aff",
      "tree": "791e2a15281bf0a3b114af6f6c9c5b2d2b0dc982",
      "parents": [
        "b9c8946b192397394a0ccd4fcecb31bc060f79f8"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Wed Oct 07 19:51:54 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Oct 07 19:51:54 2009 +0200"
      },
      "message": "cfq-iosched: fix think time allowed for seekers\n\nCFQ enables idle only for processes that think less than the allowed\nidle time. Since idle time is lower for seeky queues, we should use the\ncorrect value in the comparison.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b9c8946b192397394a0ccd4fcecb31bc060f79f8",
      "tree": "54169a387e8e4a5f6f79e06de6fbdd0096198069",
      "parents": [
        "0b182d617eb50762b483658dd6dd9a9fbcb25758"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Oct 06 20:53:44 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Oct 06 21:09:32 2009 +0200"
      },
      "message": "cfq-iosched: fix the slice residual sign\n\nWe should subtract the slice residual from the rb tree key, since\na negative residual count indicates that the cfqq overran its slice\nthe last time. Hence we want to add the overrun time, to position\nit a bit further away in the service tree.\n\nReported-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "0b182d617eb50762b483658dd6dd9a9fbcb25758",
      "tree": "28c7084cb5566cb26e5c6f96b3c055304afcbbbf",
      "parents": [
        "1b59dd511b9a36d4be3c01d7c7024aeec36dc651"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Oct 06 20:49:37 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Oct 06 20:49:37 2009 +0200"
      },
      "message": "cfq-iosched: abstract out the \u0027may this cfqq dispatch\u0027 logic\n\nMakes the whole thing easier to read, cfq_dispatch_requests() was\na bit messy before.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "23e018a1b083ecb4b8bb2fb43d58e7c19b5d7959",
      "tree": "a6361448bd596ccef393778e6f85e29413a01213",
      "parents": [
        "48e025e63ac908ed6ec5394a294f4ecd510a7476"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 05 08:52:35 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 05 11:03:58 2009 +0200"
      },
      "message": "block: get rid of kblock_schedule_delayed_work()\n\nIt was briefly introduced to allow CFQ to to delayed scheduling,\nbut we ended up removing that feature again. So lets kill the\nfunction and export, and just switch CFQ back to the normal work\nschedule since it is now passing in a \u00270\u0027 delay from all call\nsites.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "48e025e63ac908ed6ec5394a294f4ecd510a7476",
      "tree": "49828c00687c810627f00430dd56ce9901537fc9",
      "parents": [
        "30996f40bffe73f05abb92a4cec254befa8cecf7"
      ],
      "author": {
        "name": "Corrado Zoccolo",
        "email": "czoccolo@gmail.com",
        "time": "Mon Oct 05 08:49:23 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 05 11:03:55 2009 +0200"
      },
      "message": "cfq-iosched: fix possible problem with jiffies wraparound\n\nThe RR service tree is indexed by a key that is relative to current jiffies.\nThis can cause problems on jiffies wraparound.\n\nThe patch fixes it using time_before comparison, and changing\nthe add_front path to use a relative number, too.\n\nSigned-off-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "30996f40bffe73f05abb92a4cec254befa8cecf7",
      "tree": "2ce2cf9ed92aff3f930b7553711f4b439d6cb89e",
      "parents": [
        "374576a8b6f865022c0fd1ca62396889b23d66dd"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 05 11:03:39 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Oct 05 11:03:39 2009 +0200"
      },
      "message": "cfq-iosched: fix issue with rq-rq merging and fifo list ordering\n\ncfq uses rq-\u003estart_time as the fifo indicator, but that field may\nget modified prior to cfq doing it\u0027s fifo list adjustment when\na request gets merged with another request. This can cause the\nfifo list to become unordered.\n\nReported-by: Corrado Zoccolo \u003cczoccolo@gmail.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "e00c54c36ac2024c3a8a37432e2e2698ff849594",
      "tree": "0b392ba588939a7ee0c405ada8b22047fad9daff",
      "parents": [
        "ac481c20ef8f6c6f2be75d581863f40c43874ef7"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sun Oct 04 20:36:19 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sun Oct 04 20:36:19 2009 +0200"
      },
      "message": "cfq-iosched: don\u0027t delay async queue if it hasn\u0027t dispatched at all\n\nWe cannot delay for the first dispatch of the async queue if it\nhasn\u0027t dispatched at all, since that could present a local user\nDoS attack vector using an app that just did slow timed sync reads\nwhile filling memory.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "61f0c1dcaaac71faabac6ef7c839b29f20204bea",
      "tree": "81b01d1d4515fc28908446665bca17b69d44fffb",
      "parents": [
        "963b72fc6664be12ea52f35a6addea14ec373433"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 19:46:03 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 19:46:03 2009 +0200"
      },
      "message": "cfq-iosched: use assigned slice sync value, not default\n\nWe should use the sysfs modified slice sync value, in case it differs\nfrom the default.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "963b72fc6664be12ea52f35a6addea14ec373433",
      "tree": "d84e270282c4264cb7028c39c1c44804bcf2e912",
      "parents": [
        "8e2967555571659d2c8a70dd120710110ed7bba4"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 19:42:18 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 19:42:18 2009 +0200"
      },
      "message": "cfq-iosched: rename \u0027desktop\u0027 sysfs entry to \u0027low_latency\u0027\n\nDon\u0027t think that\u0027s necessarily a perfect description of what this\noption fiddles with, but it\u0027s probably better than \u0027desktop\u0027.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "8e2967555571659d2c8a70dd120710110ed7bba4",
      "tree": "22716c5388f0269f5c1cef54958ae27df256c498",
      "parents": [
        "365722bb917b08b7323b5a4a0a3386cc7d00397d"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 16:26:03 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 16:27:13 2009 +0200"
      },
      "message": "cfq-iosched: implement slower async initiate and queue ramp up\n\nThis slowly ramps up the async queue depth based on the time\npassed since the sync IO, and doesn\u0027t allow async at all until\na sync slice period has passed.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "365722bb917b08b7323b5a4a0a3386cc7d00397d",
      "tree": "e882cb339a7055169596ca4b267087bbf1672709",
      "parents": [
        "1d2235152dc745c6d94bedb550fea84cffdbf768"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Sat Oct 03 15:21:27 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Sat Oct 03 15:21:27 2009 +0200"
      },
      "message": "cfq-iosched: delay async IO dispatch, if sync IO was just done\n\no Do not allow more than max_dispatch requests from an async queue, if some\n  sync request has finished recently. This is in the hope that sync activity\n  is still going on in the system and we might receive a sync request soon.\n  Most likely from a sync queue which finished a request and we did not enable\n  idling on it.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1d2235152dc745c6d94bedb550fea84cffdbf768",
      "tree": "eb489f01dd6d506c1b785bae03e68e42145a055b",
      "parents": [
        "b0da3f0dada78832c9da03ad2152ae76bd9a2496"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Oct 02 19:27:04 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Oct 02 20:06:02 2009 +0200"
      },
      "message": "cfq-iosched: add a knob for desktop interactiveness\n\nThis is basically identical to what Vivek Goyal posted, but combined\ninto one and labelled \u0027desktop\u0027 instead of \u0027fairness\u0027. The goal\nis to continue to improve on the latency side of things as it relates\nto interactiveness, keeping the questionable bits under this sysfs\ntunable so it would be easy for throughput-only people to turn off.\n\nApart from adding the interactive sysfs knob, it also adds the\nbehavioural change of allowing slice idling even if the hardware\ndoes tagged command queuing.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "ada3fa15057205b7d3f727bba5cd26b5912e350f",
      "tree": "60962fc9e4021b92f484d1a58e72cd3906d4f3db",
      "parents": [
        "2f82af08fcc7dc01a7e98a49a5995a77e32a2925",
        "5579fd7e6aed8860ea0c8e3f11897493153b10ad"
      ],
      "author": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Tue Sep 15 09:39:44 2009 -0700"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Tue Sep 15 09:39:44 2009 -0700"
      },
      "message": "Merge branch \u0027for-linus\u0027 of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu\n\n* \u0027for-linus\u0027 of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)\n  powerpc64: convert to dynamic percpu allocator\n  sparc64: use embedding percpu first chunk allocator\n  percpu: kill lpage first chunk allocator\n  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA\n  percpu: update embedding first chunk allocator to handle sparse units\n  percpu: use group information to allocate vmap areas sparsely\n  vmalloc: implement pcpu_get_vm_areas()\n  vmalloc: separate out insert_vmalloc_vm()\n  percpu: add chunk-\u003ebase_addr\n  percpu: add pcpu_unit_offsets[]\n  percpu: introduce pcpu_alloc_info and pcpu_group_info\n  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward\n  percpu: add @align to pcpu_fc_alloc_fn_t\n  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()\n  percpu: drop @static_size from first chunk allocators\n  percpu: generalize first chunk allocator selection\n  percpu: build first chunk allocators selectively\n  percpu: rename 4k first chunk allocator to page\n  percpu: improve boot messages\n  percpu: fix pcpu_reclaim() locking\n  ...\n\nFix trivial conflict as by Tejun Heo in kernel/sched.c\n"
    },
    {
      "commit": "06d2188644c85c56d243efab914f368d1d23c4a3",
      "tree": "5ee4a4c5b6343a33573fac6a3a66015238e5b1d6",
      "parents": [
        "a9327cac440be4d8333bba975cbbf76045096275"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Sep 11 17:08:59 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Sep 14 08:24:52 2009 +0200"
      },
      "message": "cfq: choose a new next_req when a request is dispatched\n\nThis patch addresses http://bugzilla.kernel.org/show_bug.cgi?id\u003d13401, a\nregression introduced in 2.6.30.\n\nFrom the bug report:\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "b217a903ab6581cba04f88c44284dcdd2a752561",
      "tree": "4cb565ead13823c45ed325b20b83ecd78f52a565",
      "parents": [
        "49b3a3cbc0311f8f809183696b1f2ab824b18a51"
      ],
      "author": {
        "name": "Shan Wei",
        "email": "shanwei@cn.fujitsu.com",
        "time": "Tue Sep 01 10:06:42 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:34:33 2009 +0200"
      },
      "message": "cfq: fix the log message after dispatched a request\n\nThe blktrace tools can show process id when cfq dispatched a request,\nusing cfq_log_cfqq() instead of cfq_log().\n\nSigned-off-by: Shan Wei \u003cshanwei@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1b379d8daf4e981b2220f057683e35af022d45bc",
      "tree": "cc8e704bc9248c750375b23576d4659bbdc1322d",
      "parents": [
        "a33dac26d42d6f156b3b05a929961bd8d904f6e2"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Aug 11 08:26:11 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:33:32 2009 +0200"
      },
      "message": "cfq-iosched: get rid of must_alloc flag\n\nIt\u0027s not currently used, as pointed out by\nGui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e. We already check the\nwait_request flag to allow an idling queue priority allocation access,\nso we don\u0027t need this extra flag.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "1f98a13f623e0ef666690a18c1250335fc6d7ef1",
      "tree": "15ca2dddffaa18a0d1844957f4f8cc707cbb8117",
      "parents": [
        "e7e503aedb1f4d165081cb8d47a58c38f80f0cb4"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:32:04 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:33:31 2009 +0200"
      },
      "message": "bio: first step in sanitizing the bio-\u003ebi_rw flag testing\n\nGet rid of any functions that test for these bits and make callers\nuse bio_rw_flagged() directly. Then it is at least directly apparent\nwhat variable and flag they check.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "d58b85e1e891cd842d6e183f5d94d06a4fd0122c",
      "tree": "32a77721594c79610b8dba9026ff9f9928545d17",
      "parents": [
        "5ad531db6e0f3c3c985666e83d3c1c4d53acccf9"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Fri Jul 10 10:20:30 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:33:30 2009 +0200"
      },
      "message": "cfq-iosched: no need to keep track of busy_rt_queues\n\no Get rid of busy_rt_queues infrastructure. Looks like it is redundant.\n\no Once an RT queue gets request it will preempt any of the BE or IDLE queues\n  immediately. Otherwise this queue will be put on service tree and scheduler\n  will anyway select this queue before any of the BE or IDLE queue. Hence\n  looks like there is no need to keep track of how many busy RT queues are\n  currently on service tree.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "5ad531db6e0f3c3c985666e83d3c1c4d53acccf9",
      "tree": "f5bd394c493f425e12fc6991d2b7adf2121ba506",
      "parents": [
        "da6c5c720c52cc717124f8f0830b710ea6a092fd"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Jul 03 12:57:48 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Sep 11 14:33:30 2009 +0200"
      },
      "message": "cfq-iosched: drain device queue before switching to a sync queue\n\nTo lessen the impact of async IO on sync IO, let the device drain of\nany async IO in progress when switching to a sync cfqq that has idling\nenabled.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "384be2b18a5f9475eab9ca2bdfa95cc1a04ef59c",
      "tree": "04c93f391a1b65c8bf8d7ba8643c07d26c26590a",
      "parents": [
        "a76761b621bcd8336065c4fe3a74f046858bc34c",
        "142d44b0dd6741a64a7bdbe029110e7c1dcf1d23"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Fri Aug 14 14:41:02 2009 +0900"
      },
      "committer": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Fri Aug 14 14:45:31 2009 +0900"
      },
      "message": "Merge branch \u0027percpu-for-linus\u0027 into percpu-for-next\n\nConflicts:\n\tarch/sparc/kernel/smp_64.c\n\tarch/x86/kernel/cpu/perf_counter.c\n\tarch/x86/kernel/setup_percpu.c\n\tdrivers/cpufreq/cpufreq_ondemand.c\n\tmm/percpu.c\n\nConflicts in core and arch percpu codes are mostly from commit\ned78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many\nnum_possible_cpus() with nr_cpu_ids.  As for-next branch has moved all\nthe first chunk allocators into mm/percpu.c, the changes are moved\nfrom arch code to mm/percpu.c.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\n"
    },
    {
      "commit": "32f2e807a3938b24d0831211e6094f9e44b2fc83",
      "tree": "80baac86022bc36bc07a787008642149fa205642",
      "parents": [
        "ecb554a846f8e9d2a58f6d6c118168a63ac065aa"
      ],
      "author": {
        "name": "Vivek Goyal",
        "email": "vgoyal@redhat.com",
        "time": "Thu Jul 09 22:13:16 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "axboe@carl.(none)",
        "time": "Fri Jul 10 20:31:54 2009 +0200"
      },
      "message": "cfq-iosched: reset oom_cfqq in cfq_set_request()\n\nIn case memory is scarce, we now default to oom_cfqq. Once memory is\navailable again, we should allocate a new cfqq and stop using oom_cfqq for\na particular io context.\n\nOnce a new request comes in, check if we are using oom_cfqq, and if yes,\ntry to allocate a new cfqq.\n\nTested the patch by forcing the use of oom_cfqq and upon next request thread\nrealized that it was using oom_cfqq and it allocated a new cfqq.\n\nSigned-off-by: Vivek Goyal \u003cvgoyal@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "c43768cbb7655ea5ff782ae250f6e2ef4297cf98",
      "tree": "3982e41dde3eecaa3739a5d1a8ed18d04bd74f01",
      "parents": [
        "1a8dd307cc0a2119be4e578c517795464e6dabba",
        "746a99a5af60ee676afa2ba469ccd1373493c7e7"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Sat Jul 04 07:13:18 2009 +0900"
      },
      "committer": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Sat Jul 04 07:13:18 2009 +0900"
      },
      "message": "Merge branch \u0027master\u0027 into for-next\n\nPull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix\nchanges.  As alpha in percpu tree uses \u0027weak\u0027 attribute instead of\ninline assembly, there\u0027s no need for __used attribute.\n\nConflicts:\n\tarch/alpha/include/asm/percpu.h\n\tarch/mn10300/kernel/vmlinux.lds.S\n\tinclude/linux/percpu-defs.h\n"
    },
    {
      "commit": "b706f64281b24d8b1fdc8ae883700131d365c412",
      "tree": "3eed31b51cdcb2787ff2d90eaf39b19fba242a9f",
      "parents": [
        "db64f680ba4b5c56c4be59f0698000df89ff0281"
      ],
      "author": {
        "name": "Shan Wei",
        "email": "shanwei@cn.fujitsu.com",
        "time": "Wed Jul 01 12:41:14 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Jul 01 12:41:14 2009 +0200"
      },
      "message": "cfq-iosched: remove redundant check for NULL cfqq in cfq_set_request()\n\nWith the changes for falling back to an oom_cfqq, we never fail\nto find/allocate a queue in cfq_get_queue(). So remove the check.\n\nSigned-off-by: Shan Wei \u003cshanwei@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "6118b70b3a0b4c583439bb77600194c82f220ce3",
      "tree": "6966f1b059f1bdadc0d679067796d9b4bf9a22c3",
      "parents": [
        "d5036d770f871bd34c9cfd955e6dee692e1e8e81"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Jun 30 09:34:12 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Jul 01 10:56:25 2009 +0200"
      },
      "message": "cfq-iosched: get rid of the need for __GFP_NOFAIL in cfq_find_alloc_queue()\n\nSetup an emergency fallback cfqq that we allocate at IO scheduler init\ntime. If the slab allocation fails in cfq_find_alloc_queue(), we\u0027ll just\npunt IO to that cfqq instead. This ensures that cfq_find_alloc_queue()\nnever fails without having to ensure free memory.\n\nOn cfqq lookup, always try to allocate a new cfqq if the given cfq io\ncontext has the oom_cfqq assigned. This ensures that we only temporarily\npunt to this shared queue.\n\nReviewed-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "d5036d770f871bd34c9cfd955e6dee692e1e8e81",
      "tree": "d0718922511121e96bdd385d6c28a254cfc93519",
      "parents": [
        "61fd21670d048017c81e62f60894ef1b04b481db"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Fri Jun 26 10:44:34 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Jul 01 10:56:25 2009 +0200"
      },
      "message": "cfq-iosched: move cfqq initialization out of cfq_find_alloc_queue()\n\nWe\u0027re going to be needing that init code outside of that function\nto get rid of the __GFP_NOFAIL in cfqq allocation.\n\nReviewed-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "245b2e70eabd797932adb263a65da0bab3711753",
      "tree": "30f0b790dadd2b70bf06e534abcf66a76e97b05a",
      "parents": [
        "b9bf3121af348d9255f1c917830fe8c2df52efcb"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Wed Jun 24 15:13:48 2009 +0900"
      },
      "committer": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Wed Jun 24 15:13:48 2009 +0900"
      },
      "message": "percpu: clean up percpu variable definitions\n\nPercpu variable definition is about to be updated such that all percpu\nsymbols including the static ones must be unique.  Update percpu\nvariable definitions accordingly.\n\n* as,cfq: rename ioc_count uniquely\n\n* cpufreq: rename cpu_dbs_info uniquely\n\n* xen: move nesting_count out of xen_evtchn_do_upcall() and rename it\n\n* mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and\n  rename it\n\n* ipv4,6: rename cookie_scratch uniquely\n\n* x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to\n  pmc_irq_entry and nmi_entry to pmc_nmi_entry\n\n* perf_counter: rename disable_count to perf_disable_count\n\n* ftrace: rename test_event_disable to ftrace_test_event_disable\n\n* kmemleak: rename test_pointer to kmemleak_test_pointer\n\n* mce: rename next_interval to mce_next_interval\n\n[ Impact: percpu usage cleanups, no duplicate static percpu var names ]\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nReviewed-by: Christoph Lameter \u003ccl@linux-foundation.org\u003e\nCc: Ivan Kokshaysky \u003cink@jurassic.park.msu.ru\u003e\nCc: Jens Axboe \u003cjens.axboe@oracle.com\u003e\nCc: Dave Jones \u003cdavej@redhat.com\u003e\nCc: Jeremy Fitzhardinge \u003cjeremy@xensource.com\u003e\nCc: linux-mm \u003clinux-mm@kvack.org\u003e\nCc: David S. Miller \u003cdavem@davemloft.net\u003e\nCc: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nCc: Steven Rostedt \u003csrostedt@redhat.com\u003e\nCc: Li Zefan \u003clizf@cn.fujitsu.com\u003e\nCc: Catalin Marinas \u003ccatalin.marinas@arm.com\u003e\nCc: Andi Kleen \u003candi@firstfloor.org\u003e\n"
    },
    {
      "commit": "6923715ae39ed39ac2fc1993e5061668f4f71ad0",
      "tree": "98810062c76a07bf6914a192806ba2f927b3cb41",
      "parents": [
        "a979eff1811a07f5fd331c5f6f727370747b42ad"
      ],
      "author": {
        "name": "Jeff Moyer",
        "email": "jmoyer@redhat.com",
        "time": "Fri Jun 12 15:29:30 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Jun 16 08:21:04 2009 +0200"
      },
      "message": "cfq: remove extraneous \u0027\\n\u0027 in blktrace output\n\nI noticed a blank line in blktrace output.  This patch fixes that.\n\nSigned-off-by: Jeff Moyer \u003cjmoyer@redhat.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "81be834713a7d6b9463663145d493fe9daee2d61",
      "tree": "1f70583e9148554abaf4b6128bdb7d9bd8bacb6c",
      "parents": [
        "03347e2592078a90df818670fddf97a33eec70fb"
      ],
      "author": {
        "name": "Gui Jianfeng",
        "email": "guijianfeng@cn.fujitsu.com",
        "time": "Fri Jun 12 15:27:50 2009 +0200"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Tue Jun 16 08:21:03 2009 +0200"
      },
      "message": "cfq: cleanup for last_end_request in cfq_data\n\nActually, last_end_request in cfq_data isn\u0027t used now. So lets\njust remove it.\n\nSigned-off-by: Gui Jianfeng \u003cguijianfeng@cn.fujitsu.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "d9c7d394a8ebacb60097b192939ae9f15235225e",
      "tree": "4fbf9c7677acb03c23d05faba1a4b0bcfb6702b4",
      "parents": [
        "1d589bb16b825b3a7b4edd34d997f1f1f953033d"
      ],
      "author": {
        "name": "Nikanth Karthikesan",
        "email": "knikanth@novell.com",
        "time": "Wed Jun 10 12:57:06 2009 -0700"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Wed Jun 10 23:07:15 2009 +0200"
      },
      "message": "block: prevent possible io_context-\u003erefcount overflow\n\nCurrently io_context has an atomic_t(32-bit) as refcount.  In the case of\ncfq, for each device against whcih a task does I/O, a reference to the\nio_context would be taken.  And when there are multiple process sharing\nio_contexts(CLONE_IO) would also have a reference to the same io_context.\n\nTheoretically the possible maximum number of processes sharing the same\nio_context + the number of disks/cfq_data referring to the same io_context\ncan overflow the 32-bit counter on a very high-end machine.\n\nEven though it is an improbable case, let us make it atomic_long_t.\n\nSigned-off-by: Nikanth Karthikesan \u003cknikanth@suse.de\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "2e46e8b27aa57c6bd34b3102b40ee4d0144b4fab",
      "tree": "134f560f66c2af277f0f25e5b85f6c1acaddfc06",
      "parents": [
        "9780e2dd8254351f6cbe11304849126b51dbd561"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Thu May 07 22:24:41 2009 +0900"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon May 11 09:50:54 2009 +0200"
      },
      "message": "block: drop request-\u003ehard_* and *nr_sectors\n\nstruct request has had a few different ways to represent some\nproperties of a request.  -\u003ehard_* represent block layer\u0027s view of the\nrequest progress (completion cursor) and the ones without the prefix\nare supposed to represent the issue cursor and allowed to be updated\nas necessary by the low level drivers.  The thing is that as block\nlayer supports partial completion, the two cursors really aren\u0027t\nnecessary and only cause confusion.  In addition, manual management of\nrequest detail from low level drivers is cumbersome and error-prone at\nthe very least.\n\nAnother interesting duplicate fields are rq-\u003e[hard_]nr_sectors and\nrq-\u003e{hard_cur|current}_nr_sectors against rq-\u003edata_len and\nrq-\u003ebio-\u003ebi_size.  This is more convoluted than the hard_ case.\n\nrq-\u003e[hard_]nr_sectors are initialized for requests with bio but\nblk_rq_bytes() uses it only for !pc requests.  rq-\u003edata_len is\ninitialized for all request but blk_rq_bytes() uses it only for pc\nrequests.  This causes good amount of confusion throughout block layer\nand its drivers and determining the request length has been a bit of\nblack magic which may or may not work depending on circumstances and\nwhat the specific LLD is actually doing.\n\nrq-\u003e{hard_cur|current}_nr_sectors represent the number of sectors in\nthe contiguous data area at the front.  This is mainly used by drivers\nwhich transfers data by walking request segment-by-segment.  This\nvalue always equals rq-\u003ebio-\u003ebi_size \u003e\u003e 9.  However, data length for\npc requests may not be multiple of 512 bytes and using this field\nbecomes a bit confusing.\n\nIn general, having multiple fields to represent the same property\nleads only to confusion and subtle bugs.  With recent block low level\ndriver cleanups, no driver is accessing or manipulating these\nduplicate fields directly.  Drop all the duplicates.  Now rq-\u003esector\nmeans the current sector, rq-\u003edata_len the current total length and\nrq-\u003ebio-\u003ebi_size the current segment length.  Everything else is\ndefined in terms of these three and available only through accessors.\n\n* blk_recalc_rq_sectors() is collapsed into blk_update_request() and\n  now handles pc and fs requests equally other than rq-\u003esector update.\n  This means that now pc requests can use partial completion too (no\n  in-kernel user yet tho).\n\n* bio_cur_sectors() is replaced with bio_cur_bytes() as block layer\n  now uses byte count as the primary data length.\n\n* blk_rq_pos() is now guranteed to be always correct.  In-block users\n  converted.\n\n* blk_rq_bytes() is now guaranteed to be always valid as is\n  blk_rq_sectors().  In-block users converted.\n\n* blk_rq_sectors() is now guaranteed to equal blk_rq_bytes() \u003e\u003e 9.\n  More convenient one is used.\n\n* blk_rq_bytes() and blk_rq_cur_bytes() are now inlined and take const\n  pointer to request.\n\n[ Impact: API cleanup, single way to represent one property of a request ]\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nCc: Boaz Harrosh \u003cbharrosh@panasas.com\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "83096ebf1263b2c1ee5e653ba37d993d02e3eb7b",
      "tree": "2226b71a616ec1cb2d37511c6a09ba9507a1cd69",
      "parents": [
        "5b93629b4509c03ffa87a9316412fedf6f58cb37"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Thu May 07 22:24:39 2009 +0900"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon May 11 09:50:54 2009 +0200"
      },
      "message": "block: convert to pos and nr_sectors accessors\n\nWith recent cleanups, there is no place where low level driver\ndirectly manipulates request fields.  This means that the \u0027hard\u0027\nrequest fields always equal the !hard fields.  Convert all\nrq-\u003esectors, nr_sectors and current_nr_sectors references to\naccessors.\n\nWhile at it, drop superflous blk_rq_pos() \u003c 0 test in swim.c.\n\n[ Impact: use pos and nr_sectors accessors ]\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nAcked-by: Geert Uytterhoeven \u003cGeert.Uytterhoeven@sonycom.com\u003e\nTested-by: Grant Likely \u003cgrant.likely@secretlab.ca\u003e\nAcked-by: Grant Likely \u003cgrant.likely@secretlab.ca\u003e\nTested-by: Adrian McMenamin \u003cadrian@mcmen.demon.co.uk\u003e\nAcked-by: Adrian McMenamin \u003cadrian@mcmen.demon.co.uk\u003e\nAcked-by: Mike Miller \u003cmike.miller@hp.com\u003e\nCc: James Bottomley \u003cJames.Bottomley@HansenPartnership.com\u003e\nCc: Bartlomiej Zolnierkiewicz \u003cbzolnier@gmail.com\u003e\nCc: Borislav Petkov \u003cpetkovbb@googlemail.com\u003e\nCc: Sergei Shtylyov \u003csshtylyov@ru.mvista.com\u003e\nCc: Eric Moore \u003cEric.Moore@lsi.com\u003e\nCc: Alan Stern \u003cstern@rowland.harvard.edu\u003e\nCc: FUJITA Tomonori \u003cfujita.tomonori@lab.ntt.co.jp\u003e\nCc: Pete Zaitcev \u003czaitcev@redhat.com\u003e\nCc: Stephen Rothwell \u003csfr@canb.auug.org.au\u003e\nCc: Paul Clements \u003cpaul.clements@steeleye.com\u003e\nCc: Tim Waugh \u003ctim@cyberelk.net\u003e\nCc: Jeff Garzik \u003cjgarzik@pobox.com\u003e\nCc: Jeremy Fitzhardinge \u003cjeremy@xensource.com\u003e\nCc: Alex Dubov \u003coakad@yahoo.com\u003e\nCc: David Woodhouse \u003cdwmw2@infradead.org\u003e\nCc: Martin Schwidefsky \u003cschwidefsky@de.ibm.com\u003e\nCc: Dario Ballabio \u003cballabio_dario@emc.com\u003e\nCc: David S. Miller \u003cdavem@davemloft.net\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nCc: unsik Kim \u003cdonari75@gmail.com\u003e\nCc: Laurent Vivier \u003cLaurent@lvivier.info\u003e\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    }
  ],
  "next": "5b93629b4509c03ffa87a9316412fedf6f58cb37"
}