)]}'
{
  "commit": "bb97a91e2549a7f2df9c21d32542582f549ab3ec",
  "tree": "fdddcb458b74a39e97089e5bcc93234cb50704c6",
  "parents": [
    "f607c6685774811b8112e124f10a053d77015485"
  ],
  "author": {
    "name": "Peter Zijlstra",
    "email": "a.p.zijlstra@chello.nl",
    "time": "Mon Jul 20 19:15:35 2009 +0200"
  },
  "committer": {
    "name": "Ingo Molnar",
    "email": "mingo@elte.hu",
    "time": "Sun Aug 02 15:41:35 2009 +0200"
  },
  "message": "lockdep: Deal with many similar locks\n\nspin_lock_nest_lock() allows to take many instances of the same\nclass, this can easily lead to overflow of MAX_LOCK_DEPTH.\n\nTo avoid this overflow, we\u0027ll stop accounting instances but\nstart reference counting the class in the held_lock structure.\n\n[ We could maintain a list of instances, if we\u0027d move the hlock\n  stuff into __lock_acquired(), but that would require\n  significant modifications to the current code. ]\n\nWe restrict this mode to spin_lock_nest_lock() only, because it\ndegrades the lockdep quality due to lost of instance.\n\nFor lockstat this means we don\u0027t track lock statistics for any\nbut the first lock in the series.\n\nCurrently nesting is limited to 11 bits because that was the\nspare space available in held_lock. This yields a 2048\ninstances maximium.\n\nSigned-off-by: Peter Zijlstra \u003ca.p.zijlstra@chello.nl\u003e\nCc: Marcelo Tosatti \u003cmtosatti@redhat.com\u003e\nCc: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "a6d5e5e4d084a800d2e4a739d8443f5b63445d9f",
      "old_mode": 33188,
      "old_path": "include/linux/lockdep.h",
      "new_id": "47d42eff6124670ee19813f3cfc64d22d67bc4f8",
      "new_mode": 33188,
      "new_path": "include/linux/lockdep.h"
    },
    {
      "type": "modify",
      "old_id": "28914a5099142a596d6838e9ab8c9504a98f361e",
      "old_mode": 33188,
      "old_path": "kernel/lockdep.c",
      "new_id": "0bb246e21cd792eb88ac3fc45495bbde654ca01b",
      "new_mode": 33188,
      "new_path": "kernel/lockdep.c"
    }
  ]
}