)]}'
{
  "commit": "42aee6c495e07dba7410b863a360db6bb9ec6d66",
  "tree": "d014b2b5c7aa9d1a1f13686fa06699f9f734ee1c",
  "parents": [
    "9f7de8275b46d9d11b1505adbfe6c2bb48df4741"
  ],
  "author": {
    "name": "Hugh Dickins",
    "email": "hughd@google.com",
    "time": "Wed Mar 21 16:34:21 2012 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Wed Mar 21 17:55:01 2012 -0700"
  },
  "message": "cgroup: revert ss_id_lock to spinlock\n\nCommit c1e2ee2dc436 (\"memcg: replace ss-\u003eid_lock with a rwlock\") has now\nbeen seen to cause the unfair behavior we should have expected from\nconverting a spinlock to an rwlock: softlockup in cgroup_mkdir(), whose\nget_new_cssid() is waiting for the wlock, while there are 19 tasks using\nthe rlock in css_get_next() to get on with their memcg workload (in an\nartificial test, admittedly).  Yet lib/idr.c was made suitable for RCU\nway back: revert that commit, restoring ss-\u003eid_lock to a spinlock.\n\nSigned-off-by: Hugh Dickins \u003chughd@google.com\u003e\nAcked-by: KAMEZAWA Hiroyuki \u003ckamezawa.hiroyu@jp.fujitsu.com\u003e\nAcked-by: Li Zefan \u003clizf@cn.fujitsu.com\u003e\nCc: Eric Dumazet \u003ceric.dumazet@gmail.com\u003e\nAcked-by: Tejun Heo \u003ctj@kernel.org\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "501adb1b2f439f9ec746ba9a83b1f243682a9237",
      "old_mode": 33188,
      "old_path": "include/linux/cgroup.h",
      "new_id": "5a85b3415c1b56b971f54a6f65e87ea1bf5e64af",
      "new_mode": 33188,
      "new_path": "include/linux/cgroup.h"
    },
    {
      "type": "modify",
      "old_id": "c6877fe9a831057759899555326d55933c1b467b",
      "old_mode": 33188,
      "old_path": "kernel/cgroup.c",
      "new_id": "8eb90f25bd7b13341acf66bb6a0c8d796e3b064c",
      "new_mode": 33188,
      "new_path": "kernel/cgroup.c"
    }
  ]
}