)]}'
{
  "log": [
    {
      "commit": "5a0e3ad6af8660be21ca98a971cd00f331318c05",
      "tree": "5bfb7be11a03176a87296a43ac6647975c00a1d1",
      "parents": [
        "ed391f4ebf8f701d3566423ce8f17e614cde9806"
      ],
      "author": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Wed Mar 24 17:04:11 2010 +0900"
      },
      "committer": {
        "name": "Tejun Heo",
        "email": "tj@kernel.org",
        "time": "Tue Mar 30 22:02:32 2010 +0900"
      },
      "message": "include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h\n\npercpu.h is included by sched.h and module.h and thus ends up being\nincluded when building most .c files.  percpu.h includes slab.h which\nin turn includes gfp.h making everything defined by the two files\nuniversally available and complicating inclusion dependencies.\n\npercpu.h -\u003e slab.h dependency is about to be removed.  Prepare for\nthis change by updating users of gfp and slab facilities include those\nheaders directly instead of assuming availability.  As this conversion\nneeds to touch large number of source files, the following script is\nused as the basis of conversion.\n\n  http://userweb.kernel.org/~tj/misc/slabh-sweep.py\n\nThe script does the followings.\n\n* Scan files for gfp and slab usages and update includes such that\n  only the necessary includes are there.  ie. if only gfp is used,\n  gfp.h, if slab is used, slab.h.\n\n* When the script inserts a new include, it looks at the include\n  blocks and try to put the new include such that its order conforms\n  to its surrounding.  It\u0027s put in the include block which contains\n  core kernel includes, in the same order that the rest are ordered -\n  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there\n  doesn\u0027t seem to be any matching order.\n\n* If the script can\u0027t find a place to put a new include (mostly\n  because the file doesn\u0027t have fitting include block), it prints out\n  an error message indicating which .h file needs to be added to the\n  file.\n\nThe conversion was done in the following steps.\n\n1. The initial automatic conversion of all .c files updated slightly\n   over 4000 files, deleting around 700 includes and adding ~480 gfp.h\n   and ~3000 slab.h inclusions.  The script emitted errors for ~400\n   files.\n\n2. Each error was manually checked.  Some didn\u0027t need the inclusion,\n   some needed manual addition while adding it to implementation .h or\n   embedding .c file was more appropriate for others.  This step added\n   inclusions to around 150 files.\n\n3. The script was run again and the output was compared to the edits\n   from #2 to make sure no file was left behind.\n\n4. Several build tests were done and a couple of problems were fixed.\n   e.g. lib/decompress_*.c used malloc/free() wrappers around slab\n   APIs requiring slab.h to be added manually.\n\n5. The script was run on all .h files but without automatically\n   editing them as sprinkling gfp.h and slab.h inclusions around .h\n   files could easily lead to inclusion dependency hell.  Most gfp.h\n   inclusion directives were ignored as stuff from gfp.h was usually\n   wildly available and often used in preprocessor macros.  Each\n   slab.h inclusion directive was examined and added manually as\n   necessary.\n\n6. percpu.h was updated not to include slab.h.\n\n7. Build test were done on the following configurations and failures\n   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my\n   distributed build env didn\u0027t work with gcov compiles) and a few\n   more options had to be turned off depending on archs to make things\n   build (like ipr on powerpc/64 which failed due to missing writeq).\n\n   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.\n   * powerpc and powerpc64 SMP allmodconfig\n   * sparc and sparc64 SMP allmodconfig\n   * ia64 SMP allmodconfig\n   * s390 SMP allmodconfig\n   * alpha SMP allmodconfig\n   * um on x86_64 SMP allmodconfig\n\n8. percpu.h modifications were reverted so that it could be applied as\n   a separate patch and serve as bisection point.\n\nGiven the fact that I had only a couple of failures from tests on step\n6, I\u0027m fairly confident about the coverage of this conversion patch.\nIf there is a breakage, it\u0027s likely to be something in one of the arch\nheaders which should be easily discoverable easily on most builds of\nthe specific arch.\n\nSigned-off-by: Tejun Heo \u003ctj@kernel.org\u003e\nGuess-its-ok-by: Christoph Lameter \u003ccl@linux-foundation.org\u003e\nCc: Ingo Molnar \u003cmingo@redhat.com\u003e\nCc: Lee Schermerhorn \u003cLee.Schermerhorn@hp.com\u003e\n"
    },
    {
      "commit": "6f054164322bc6c1233402b9ed6b40d4af39a98f",
      "tree": "8bf63b1220db094a6865ff5254a3c55781e89b38",
      "parents": [
        "29e553631b2a0d4eebd23db630572e1027a9967a"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Tue Dec 01 13:38:45 2009 +0000"
      },
      "committer": {
        "name": "Linus Torvalds",
        "email": "torvalds@linux-foundation.org",
        "time": "Tue Dec 01 07:35:11 2009 -0800"
      },
      "message": "9p: fix build breakage introduced by FS-Cache\n\nWhile building 2.6.32-rc8-git2 for Fedora I noticed the following thinko\nin commit 201a15428bd54f83eccec8b7c64a04b8f9431204 (\"FS-Cache: Handle\npages pending storage that get evicted under OOM conditions\"):\n\n  fs/9p/cache.c: In function \u0027__v9fs_fscache_release_page\u0027:\n  fs/9p/cache.c:346: error: \u0027vnode\u0027 undeclared (first use in this function)\n  fs/9p/cache.c:346: error: (Each undeclared identifier is reported only once\n  fs/9p/cache.c:346: error: for each function it appears in.)\n  make[2]: *** [fs/9p/cache.o] Error 1\n\nFix the 9P filesystem to correctly construct the argument to\nfscache_maybe_release_page().\n\nSigned-off-by: Kyle McMartin \u003ckyle@redhat.com\u003e\nSigned-off-by: Xiaotian Feng \u003cdfeng@redhat.com\u003e [from identical patch]\nSigned-off-by: Stefan Lippers-Hollmann \u003cs.l-h@gmx.de\u003e [from identical patch]\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n"
    },
    {
      "commit": "201a15428bd54f83eccec8b7c64a04b8f9431204",
      "tree": "326fcce64ce96657253fd141a3f4a767ac95418a",
      "parents": [
        "e3d4d28b1c8cc7c26536a50b43d86ccd39878550"
      ],
      "author": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:35 2009 +0000"
      },
      "committer": {
        "name": "David Howells",
        "email": "dhowells@redhat.com",
        "time": "Thu Nov 19 18:11:35 2009 +0000"
      },
      "message": "FS-Cache: Handle pages pending storage that get evicted under OOM conditions\n\nHandle netfs pages that the vmscan algorithm wants to evict from the pagecache\nunder OOM conditions, but that are waiting for write to the cache.  Under these\nconditions, vmscan calls the releasepage() function of the netfs, asking if a\npage can be discarded.\n\nThe problem is typified by the following trace of a stuck process:\n\n\tkslowd005     D 0000000000000000     0  4253      2 0x00000080\n\t ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007\n\t 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8\n\t 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8\n\tCall Trace:\n\t [\u003cffffffffa00782d8\u003e] __fscache_wait_on_page_write+0x8b/0xa7 [fscache]\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffffa0078240\u003e] ? __fscache_check_page_write+0x63/0x70 [fscache]\n\t [\u003cffffffffa00b671d\u003e] nfs_fscache_release_page+0x4e/0xc4 [nfs]\n\t [\u003cffffffffa00927f0\u003e] nfs_release_page+0x3c/0x41 [nfs]\n\t [\u003cffffffff810885d3\u003e] try_to_release_page+0x32/0x3b\n\t [\u003cffffffff81093203\u003e] shrink_page_list+0x316/0x4ac\n\t [\u003cffffffff8109372b\u003e] shrink_inactive_list+0x392/0x67c\n\t [\u003cffffffff813532fa\u003e] ? __mutex_unlock_slowpath+0x100/0x10b\n\t [\u003cffffffff81058df0\u003e] ? trace_hardirqs_on_caller+0x10c/0x130\n\t [\u003cffffffff8135330e\u003e] ? mutex_unlock+0x9/0xb\n\t [\u003cffffffff81093aa2\u003e] shrink_list+0x8d/0x8f\n\t [\u003cffffffff81093d1c\u003e] shrink_zone+0x278/0x33c\n\t [\u003cffffffff81052d6c\u003e] ? ktime_get_ts+0xad/0xba\n\t [\u003cffffffff81094b13\u003e] try_to_free_pages+0x22e/0x392\n\t [\u003cffffffff81091e24\u003e] ? isolate_pages_global+0x0/0x212\n\t [\u003cffffffff8108e743\u003e] __alloc_pages_nodemask+0x3dc/0x5cf\n\t [\u003cffffffff81089529\u003e] grab_cache_page_write_begin+0x65/0xaa\n\t [\u003cffffffff8110f8c0\u003e] ext3_write_begin+0x78/0x1eb\n\t [\u003cffffffff81089ec5\u003e] generic_file_buffered_write+0x109/0x28c\n\t [\u003cffffffff8103cb69\u003e] ? current_fs_time+0x22/0x29\n\t [\u003cffffffff8108a509\u003e] __generic_file_aio_write+0x350/0x385\n\t [\u003cffffffff8108a588\u003e] ? generic_file_aio_write+0x4a/0xae\n\t [\u003cffffffff8108a59e\u003e] generic_file_aio_write+0x60/0xae\n\t [\u003cffffffff810b2e82\u003e] do_sync_write+0xe3/0x120\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff810b18e1\u003e] ? __dentry_open+0x1a5/0x2b8\n\t [\u003cffffffff810b1a76\u003e] ? dentry_open+0x82/0x89\n\t [\u003cffffffffa00e693c\u003e] cachefiles_write_page+0x298/0x335 [cachefiles]\n\t [\u003cffffffffa0077147\u003e] fscache_write_op+0x178/0x2c2 [fscache]\n\t [\u003cffffffffa0075656\u003e] fscache_op_execute+0x7a/0xd1 [fscache]\n\t [\u003cffffffff81082093\u003e] slow_work_execute+0x18f/0x2d1\n\t [\u003cffffffff8108239a\u003e] slow_work_thread+0x1c5/0x308\n\t [\u003cffffffff8104c0f1\u003e] ? autoremove_wake_function+0x0/0x34\n\t [\u003cffffffff810821d5\u003e] ? slow_work_thread+0x0/0x308\n\t [\u003cffffffff8104be91\u003e] kthread+0x7a/0x82\n\t [\u003cffffffff8100beda\u003e] child_rip+0xa/0x20\n\t [\u003cffffffff8100b87c\u003e] ? restore_args+0x0/0x30\n\t [\u003cffffffff8102ef83\u003e] ? tg_shares_up+0x171/0x227\n\t [\u003cffffffff8104be17\u003e] ? kthread+0x0/0x82\n\t [\u003cffffffff8100bed0\u003e] ? child_rip+0x0/0x20\n\nIn the above backtrace, the following is happening:\n\n (1) A page storage operation is being executed by a slow-work thread\n     (fscache_write_op()).\n\n (2) FS-Cache farms the operation out to the cache to perform\n     (cachefiles_write_page()).\n\n (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3\u0027s\n     standard write (do_sync_write()) under KERNEL_DS directly from the netfs\n     page.\n\n (4) However, for Ext3 to perform the write, it must allocate some memory, in\n     particular, it must allocate at least one page cache page into which it\n     can copy the data from the netfs page.\n\n (5) Under OOM conditions, the memory allocator can\u0027t immediately come up with\n     a page, so it uses vmscan to find something to discard\n     (try_to_free_pages()).\n\n (6) vmscan finds a clean netfs page it might be able to discard (possibly the\n     one it\u0027s trying to write out).\n\n (7) The netfs is called to throw the page away (nfs_release_page()) - but it\u0027s\n     called with __GFP_WAIT, so the netfs decides to wait for the store to\n     complete (__fscache_wait_on_page_write()).\n\n (8) This blocks a slow-work processing thread - possibly against itself.\n\nThe system ends up stuck because it can\u0027t write out any netfs pages to the\ncache without allocating more memory.\n\nTo avoid this, we make FS-Cache cancel some writes that aren\u0027t in the middle of\nactually being performed.  This means that some data won\u0027t make it into the\ncache this time.  To support this, a new FS-Cache function is added\nfscache_maybe_release_page() that replaces what the netfs releasepage()\nfunctions used to do with respect to the cache.\n\nThe decisions fscache_maybe_release_page() makes are counted and displayed\nthrough /proc/fs/fscache/stats on a line labelled \"VmScan\".  There are four\ncounters provided: \"nos\u003dN\" - pages that weren\u0027t pending storage; \"gon\u003dN\" -\npages that were pending storage when we first looked, but weren\u0027t by the time\nwe got the object lock; \"bsy\u003dN\" - pages that we ignored as they were actively\nbeing written when we looked; and \"can\u003dN\" - pages that we cancelled the storage\nof.\n\nWhat I\u0027d really like to do is alter the behaviour of the cancellation\nheuristics, depending on how necessary it is to expel pages.  If there are\nplenty of other pages that aren\u0027t waiting to be written to the cache that\ncould be ejected first, then it would be nice to hold up on immediate\ncancellation of cache writes - but I don\u0027t see a way of doing that.\n\nSigned-off-by: David Howells \u003cdhowells@redhat.com\u003e\n"
    },
    {
      "commit": "60e78d2c993e58d890596d951fff77d5965adcd6",
      "tree": "3d53ed7254c613ef8d8de36fdceda25bc493f4f7",
      "parents": [
        "637d020a02cd734bf27acfc56c6d942cddd9eb80"
      ],
      "author": {
        "name": "Abhishek Kulkarni",
        "email": "adkulkar@umail.iu.edu",
        "time": "Wed Sep 23 13:00:27 2009 -0500"
      },
      "committer": {
        "name": "Eric Van Hensbergen",
        "email": "ericvh@strongmad.austin.ibm.com",
        "time": "Wed Sep 23 13:03:46 2009 -0500"
      },
      "message": "9p: Add fscache support to 9p\n\nThis patch adds a persistent, read-only caching facility for\n9p clients using the FS-Cache caching backend.\n\nWhen the fscache facility is enabled, each inode is associated\nwith a corresponding vcookie which is an index into the FS-Cache\nindexing tree. The FS-Cache indexing tree is indexed at 3 levels:\n- session object associated with each mount.\n- inode/vcookie\n- actual data (pages)\n\nA cache tag is chosen randomly for each session. These tags can\nbe read off /sys/fs/9p/caches and can be passed as a mount-time\nparameter to re-attach to the specified caching session.\n\nSigned-off-by: Abhishek Kulkarni \u003cadkulkar@umail.iu.edu\u003e\nSigned-off-by: Eric Van Hensbergen \u003cericvh@gmail.com\u003e\n"
    }
  ]
}
