)]}'
{
  "commit": "b8900bc0217fac8e68085997bee2f05e6db931a2",
  "tree": "43c7ddba331b1cf3d7c984e7b0ba528cd295b44d",
  "parents": [
    "e12d0271774fea9fddf1e2a7952a0bffb2ee8e8b"
  ],
  "author": {
    "name": "Frederic Weisbecker",
    "email": "fweisbec@gmail.com",
    "time": "Thu Jun 06 15:42:53 2013 +0200"
  },
  "committer": {
    "name": "Frederic Weisbecker",
    "email": "fweisbec@gmail.com",
    "time": "Thu Jun 20 01:16:09 2013 +0200"
  },
  "message": "watchdog: Register / unregister watchdog kthreads on sysctl control\n\nThe user activation/deactivation of the watchdog through boot parameters\nor systcl is currently implemented with a dance involving kthreads parking\nand unparking methods: the threads are unconditionally registered on\nboot and they park as soon as the user want the watchdog to be disabled.\n\nThis method involves a few noisy details to handle though: the watchdog\nkthreads may be unparked anytime due to hotplug operations, after which\nthe watchdog internals have to decide to park again if it is user-disabled.\n\nAs a result the setup() and unpark() methods need to be able to request a\nreparking. This is not currently supported in the kthread infrastructure\nso this piece of the watchdog code only works halfway.\n\nBesides, unparking/reparking the watchdog kthreads consume unnecessary\ncputime on hotplug operations when those could be simply ignored in the\nfirst place.\n\nAs suggested by Srivatsa, let\u0027s instead only register the watchdog\nthreads when they are needed. This way we don\u0027t need to think about\nhotplug operations and we don\u0027t burden the CPU onlining when the watchdog\nis simply disabled.\n\nSuggested-by: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nSigned-off-by: Frederic Weisbecker \u003cfweisbec@gmail.com\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Anish Singh \u003canish198519851985@gmail.com\u003e\nCc: Steven Rostedt \u003crostedt@goodmis.org\u003e\nCc: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Ingo Molnar \u003cmingo@kernel.org\u003e\nCc: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nCc: Borislav Petkov \u003cbp@alien8.de\u003e\nCc: Li Zhong \u003czhong@linux.vnet.ibm.com\u003e\nCc: Don Zickus \u003cdzickus@redhat.com\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "05039e348f07e242c63392a8758b8371c1a42beb",
      "old_mode": 33188,
      "old_path": "kernel/watchdog.c",
      "new_id": "52c9a9b91bdd40cfa6a76e29abe4e9fa38fd74bb",
      "new_mode": 33188,
      "new_path": "kernel/watchdog.c"
    }
  ]
}