)]}'
{
  "log": [
    {
      "commit": "4ac845a2e9a816ed5a7b301f56dcc0a3d0b1ba4d",
      "tree": "602f15808d0f3dcdfcd7cc4491b2cc2ccd266fd2",
      "parents": [
        "66dac98ed0de7a1125fb0dd7907f238f6b9d2f60"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Jan 24 08:44:49 2008 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Jan 28 10:50:33 2008 +0100"
      },
      "message": "block: cfq: make the io contect sharing lockless\n\nThe io context sharing introduced a per-ioc spinlock, that would protect\nthe cfq io context lookup. That is a regression from the original, since\nwe never needed any locking there because the ioc/cic were process private.\n\nThe cic lookup is changed from an rbtree construct to a radix tree, which\nwe can then use RCU to make the reader side lockless. That is the performance\ncritical path, modifying the radix tree is only done on process creation\n(when that process first does IO, actually) and on process exit (if that\nprocess has done IO).\n\nAs it so happens, radix trees are also much faster for this type of\nlookup where the key is a pointer. It\u0027s a very sparse tree.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "d38ecf935fcb10264a6bc190855d9595165e6eeb",
      "tree": "64e3146ef76678ad3ae8f75c32df9f25ea470953",
      "parents": [
        "fd0928df98b9578be8a786ac0cb78a47a5e17a20"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Jan 24 08:53:35 2008 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Jan 28 10:50:31 2008 +0100"
      },
      "message": "io context sharing: preliminary support\n\nDetach task state from ioc, instead keep track of how many processes\nare accessing the ioc.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    },
    {
      "commit": "fd0928df98b9578be8a786ac0cb78a47a5e17a20",
      "tree": "70a34cf207bea1bec28e59cf0dba7d20e7f8b0f1",
      "parents": [
        "91525300baf162e83e923b09ca286f9205e21522"
      ],
      "author": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Thu Jan 24 08:52:45 2008 +0100"
      },
      "committer": {
        "name": "Jens Axboe",
        "email": "jens.axboe@oracle.com",
        "time": "Mon Jan 28 10:50:29 2008 +0100"
      },
      "message": "ioprio: move io priority from task_struct to io_context\n\nThis is where it belongs and then it doesn\u0027t take up space for a\nprocess that doesn\u0027t do IO.\n\nSigned-off-by: Jens Axboe \u003cjens.axboe@oracle.com\u003e\n"
    }
  ]
}