)]}'
{
  "log": [
    {
      "commit": "9a59d64256bad8ce156acd44c533f66cf9879c95",
      "tree": "c68f53d75330e4d9857dcd1f856d1d34c8c5d0f3",
      "parents": [
        "b0de7572f02ecc18dd73e653e4f46bf68ed1a21f"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Tue Feb 26 18:44:33 2013 +0100"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:58 2014 -0700"
      },
      "message": "stop_machine: Mark per cpu stopper enabled early\n\ncommit 14e568e78 (stop_machine: Use smpboot threads) introduced the\nfollowing regression:\n\nBefore this commit the stopper enabled bit was set in the online\nnotifier.\n\nCPU0\t\t\t\tCPU1\ncpu_up\n\t\t\t\tcpu online\nhotplug_notifier(ONLINE)\n  stopper(CPU1)-\u003eenabled \u003d true;\n...\nstop_machine()\n\nThe conversion to smpboot threads moved the enablement to the wakeup\npath of the parked thread. The majority of users seem to have the\nfollowing working order:\n\nCPU0\t\t\t\tCPU1\ncpu_up\n\t\t\t\tcpu online\nunpark_threads()\n  wakeup(stopper[CPU1])\n....\n\t\t\t\tstopper thread runs\n\t\t\t\t  stopper(CPU1)-\u003eenabled \u003d true;\nstop_machine()\n\nBut Konrad and Sander have observed:\n\nCPU0\t\t\t\tCPU1\ncpu_up\n\t\t\t\tcpu online\nunpark_threads()\n  wakeup(stopper[CPU1])\n....\nstop_machine()\n\t\t\t\tstopper thread runs\n\t\t\t\t  stopper(CPU1)-\u003eenabled \u003d true;\n\nNow the stop machinery kicks CPU0 into the stop loop, where it gets\nstuck forever because the queue code saw stopper(CPU1)-\u003eenabled \u003d\u003d\nfalse, so CPU0 waits for CPU1 to enter stomp_machine, but the CPU1\nstopper work got discarded due to enabled \u003d\u003d false.\n\nAdd a pre_unpark function to the smpboot thread descriptor and call it\nbefore waking the thread.\n\nThis fixes the problem at hand, but the stop_machine code should be\nmore robust. The stopper-\u003eenabled flag smells fishy at best.\n\nThanks to Konrad for going through a loop of debug patches and\nproviding the information to decode this issue.\n\nReported-and-tested-by: Konrad Rzeszutek Wilk \u003ckonrad.wilk@oracle.com\u003e\nReported-and-tested-by: Sander Eikelenboom \u003clinux@eikelenboom.it\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nLink: http://lkml.kernel.org/r/alpine.LFD.2.02.1302261843240.22263@ionos\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: Iaff8824879eb21552fc9e46e259b604dfce113bc\n"
    },
    {
      "commit": "bb32d268211f1c70858a32e1402ecc09af173205",
      "tree": "d8f191500ea1020ed0028fadc23ece0d7c3ee973",
      "parents": [
        "ceced05d7f2bedf5da09f4eb48075339cc23876e"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Tue Apr 09 09:33:34 2013 +0200"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:56 2014 -0700"
      },
      "message": "kthread: Prevent unpark race which puts threads on the wrong cpu\n\nThe smpboot threads rely on the park/unpark mechanism which binds per\ncpu threads on a particular core. Though the functionality is racy:\n\nCPU0\t       \t \tCPU1  \t     \t    CPU2\nunpark(T)\t\t\t\t    wake_up_process(T)\n  clear(SHOULD_PARK)\tT runs\n\t\t\tleave parkme() due to !SHOULD_PARK\n  bind_to(CPU2)\t\tBUG_ON(wrong CPU)\n\nWe cannot let the tasks move themself to the target CPU as one of\nthose tasks is actually the migration thread itself, which requires\nthat it starts running on the target cpu right away.\n\nThe solution to this problem is to prevent wakeups in park mode which\nare not from unpark(). That way we can guarantee that the association\nof the task to the target cpu is working correctly.\n\nAdd a new task state (TASK_PARKED) which prevents other wakeups and\nuse this state explicitly for the unpark wakeup.\n\nPeter noticed: Also, since the task state is visible to userspace and\nall the parked tasks are still in the PID space, its a good hint in ps\nand friends that these tasks aren\u0027t really there for the moment.\n\nThe migration thread has another related issue.\n\nCPU0\t      \t     \t CPU1\nBring up CPU2\ncreate_thread(T)\npark(T)\n wait_for_completion()\n\t\t\t parkme()\n\t\t\t complete()\nsched_set_stop_task()\n\t\t\t schedule(TASK_PARKED)\n\nThe sched_set_stop_task() call is issued while the task is on the\nrunqueue of CPU1 and that confuses the hell out of the stop_task class\non that cpu. So we need the same synchronizaion before\nsched_set_stop_task().\n\nReported-by: Dave Jones \u003cdavej@redhat.com\u003e\nReported-and-tested-by: Dave Hansen \u003cdave@sr71.net\u003e\nReported-and-tested-by: Borislav Petkov \u003cbp@alien8.de\u003e\nAcked-by: Peter Ziljstra \u003cpeterz@infradead.org\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: dhillf@gmail.com\nCc: Ingo Molnar \u003cmingo@kernel.org\u003e\nCc: stable@vger.kernel.org\nLink: http://lkml.kernel.org/r/alpine.LFD.2.02.1304091635430.21884@ionos\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: If1e9993951c4ad1f6f35ad0698f6ccd05a67e81f\n"
    },
    {
      "commit": "ceced05d7f2bedf5da09f4eb48075339cc23876e",
      "tree": "766043bd6b44b5126b3d68deeef2fda57a15a5e4",
      "parents": [
        "04d903e40c1030e78f5953e7a904f03ab4e4fc34"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Thu Jan 31 12:11:12 2013 +0000"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:56 2014 -0700"
      },
      "message": "smpboot: Allow selfparking per cpu threads\n\nThe stop machine threads are still killed when a cpu goes offline. The\nreason is that the thread is used to bring the cpu down, so it can\u0027t\nbe parked along with the other per cpu threads.\n\nAllow a per cpu thread to be excluded from automatic parking, so it\ncan park itself once it\u0027s done\n\nAdd a create callback function as well.\n\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nCc: Paul McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Arjan van de Veen \u003carjan@infradead.org\u003e\nCc: Paul Turner \u003cpjt@google.com\u003e\nCc: Richard Weinberger \u003crw@linutronix.de\u003e\nCc: Magnus Damm \u003cmagnus.damm@gmail.com\u003e\nLink: http://lkml.kernel.org/r/20130131120741.553993267@linutronix.de\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: I864f39336a2cb648c518526459929c081f831216\n"
    },
    {
      "commit": "04d903e40c1030e78f5953e7a904f03ab4e4fc34",
      "tree": "4eded8134694e474f844a2fbb52c63521b252739",
      "parents": [
        "a63b4ccf0332e6ddea65fa473dc0912e8433432f"
      ],
      "author": {
        "name": "Paul E. McKenney",
        "email": "paul.mckenney@linaro.org",
        "time": "Thu Jul 12 01:55:54 2012 -0700"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:55 2014 -0700"
      },
      "message": "hotplug: Fix UP bug in smpboot hotplug code\n\nBecause kernel subsystems need their per-CPU kthreads on UP systems as\nwell as on SMP systems, the smpboot hotplug kthread functions must be\nprovided in UP builds as well as in SMP builds.  This commit therefore\nadds smpboot.c to UP builds and excludes irrelevant code via #ifdef.\n\nSigned-off-by: Paul E. McKenney \u003cpaul.mckenney@linaro.org\u003e\nSigned-off-by: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: I7b570d6c241c513227c3fdc1d843bf369bed036c\n"
    },
    {
      "commit": "a63b4ccf0332e6ddea65fa473dc0912e8433432f",
      "tree": "f96709aa87d8ea7a4bf81d9c0e54ffa151cb6180",
      "parents": [
        "20bdb6ed0478fc5d79e1fb3f9ae97808a2670fee"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Mon Jul 16 10:42:36 2012 +0000"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:55 2014 -0700"
      },
      "message": "smpboot: Provide infrastructure for percpu hotplug threads\n\nProvide a generic interface for setting up and tearing down percpu\nthreads.\n\nOn registration the threads for already online cpus are created and\nstarted. On deregistration (modules) the threads are stoppped.\n\nDuring hotplug operations the threads are created, started, parked and\nunparked. The datastructure for registration provides a pointer to\npercpu storage space and optional setup, cleanup, park, unpark\nfunctions. These functions are called when the thread state changes.\n\nEach implementation has to provide a function which is queried and\nreturns whether the thread should run and the thread function itself.\n\nThe core code handles all state transitions and avoids duplicated code\nin the call sites.\n\n[ paulmck: Preemption leak fix ]\n\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nReviewed-by: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nReviewed-by: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Namhyung Kim \u003cnamhyung@kernel.org\u003e\nLink: http://lkml.kernel.org/r/20120716103948.352501068@linutronix.de\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: Ib2ac667cd13cf26a042d65c1b3f20fe7e4b02423\n"
    },
    {
      "commit": "d5d863438d56dd89f31d23a350ea745088d1c754",
      "tree": "0c503b29f7cb1d520164dd92cd0f9bfb26f98515",
      "parents": [
        "d7ee3647abc09781343e58c75a103f6e421e841e"
      ],
      "author": {
        "name": "Srivatsa S. Bhat",
        "email": "srivatsa.bhat@linux.vnet.ibm.com",
        "time": "Thu May 24 20:41:00 2012 +0530"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:54 2014 -0700"
      },
      "message": "smpboot, idle: Fix comment mismatch over idle_threads_init()\n\nThe comment over idle_threads_init() really talks about the functionality\nof idle_init(). Move that comment to idle_init(), and add a suitable\ncomment over idle_threads_init().\n\nSigned-off-by: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: suresh.b.siddha@intel.com\nCc: venki@google.com\nCc: nikunj@linux.vnet.ibm.com\nLink: http://lkml.kernel.org/r/20120524151100.2549.66501.stgit@srivatsabhat.in.ibm.com\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: Ib0cd6d6e19e0c64868a42a77101b080a5f3b04f8\n"
    },
    {
      "commit": "d7ee3647abc09781343e58c75a103f6e421e841e",
      "tree": "cadd17cd08b49e827d3f64082bb645629ff231e5",
      "parents": [
        "ad6a2c704a934a832a9e90fdfa15cc7c2f144437"
      ],
      "author": {
        "name": "Srivatsa S. Bhat",
        "email": "srivatsa.bhat@linux.vnet.ibm.com",
        "time": "Thu May 24 20:40:55 2012 +0530"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:53 2014 -0700"
      },
      "message": "smpboot, idle: Optimize calls to smp_processor_id() in idle_threads_init()\n\nWhile trying to initialize idle threads for all cpus, idle_threads_init()\ncalls smp_processor_id() in a loop, which is unnecessary. The intent\nis to initialize idle threads for all non-boot cpus. So just use a variable\nto note the boot cpu and use it in the loop.\n\nSigned-off-by: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: suresh.b.siddha@intel.com\nCc: venki@google.com\nCc: nikunj@linux.vnet.ibm.com\nLink: http://lkml.kernel.org/r/20120524151055.2549.64309.stgit@srivatsabhat.in.ibm.com\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: Ib65df4c31e93e1622c26f2c2a4946ffd28c1839d\n"
    },
    {
      "commit": "ad6a2c704a934a832a9e90fdfa15cc7c2f144437",
      "tree": "c5523330b69324738f7c3d79265415f937074fec",
      "parents": [
        "c5989bd43645dbb5d48197b02397565d1ceffa29"
      ],
      "author": {
        "name": "Suresh Siddha",
        "email": "suresh.b.siddha@intel.com",
        "time": "Fri Apr 20 17:08:50 2012 -0700"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:53 2014 -0700"
      },
      "message": "smp, idle: Allocate idle thread for each possible cpu during boot\n\npercpu areas are already allocated during boot for each possible cpu.\npercpu idle threads can be considered as an extension of the percpu areas,\nand allocate them for each possible cpu during boot.\n\nThis will eliminate the need for workqueue based idle thread allocation.\nIn future we can move the idle thread area into the percpu area too.\n\n[ tglx: Moved the loop into smpboot.c and added an error check when\n  the init code failed to allocate an idle thread for a cpu which\n  should be onlined ]\n\nSigned-off-by: Suresh Siddha \u003csuresh.b.siddha@intel.com\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nCc: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Tejun Heo \u003ctj@kernel.org\u003e\nCc: David Rientjes \u003crientjes@google.com\u003e\nCc: venki@google.com\nLink: http://lkml.kernel.org/r/1334966930.28674.245.camel@sbsiddha-desk.sc.intel.com\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n\nChange-Id: I36828165fc08b7c0a8a0fe6a2aa24d358e623dd2\n"
    },
    {
      "commit": "c5989bd43645dbb5d48197b02397565d1ceffa29",
      "tree": "bda6cd4ad20680299c06d3c459804f92ec44dbdb",
      "parents": [
        "33d588d0d93e7bf0af4b05420585bfc5df474e63"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Fri Apr 20 13:05:45 2012 +0000"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:53 2014 -0700"
      },
      "message": "smp: Provide generic idle thread allocation\n\nAll SMP architectures have magic to fork the idle task and to store it\nfor reusage when cpu hotplug is enabled. Provide a generic\ninfrastructure for it.\n\nCreate/reinit the idle thread for the cpu which is brought up in the\ngeneric code and hand the thread pointer to the architecture code via\n__cpu_up().\n\nNote, that fork_idle() is called via a workqueue, because this\nguarantees that the idle thread does not get a reference to a user\nspace VM. This can happen when the boot process did not bring up all\npossible cpus and a later cpu_up() is initiated via the sysfs\ninterface. In that case fork_idle() would be called in the context of\nthe user space task and take a reference on the user space VM.\n\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nCc: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Matt Turner \u003cmattst88@gmail.com\u003e\nCc: Russell King \u003clinux@arm.linux.org.uk\u003e\nCc: Mike Frysinger \u003cvapier@gentoo.org\u003e\nCc: Jesper Nilsson \u003cjesper.nilsson@axis.com\u003e\nCc: Richard Kuo \u003crkuo@codeaurora.org\u003e\nCc: Tony Luck \u003ctony.luck@intel.com\u003e\nCc: Hirokazu Takata \u003ctakata@linux-m32r.org\u003e\nCc: Ralf Baechle \u003cralf@linux-mips.org\u003e\nCc: David Howells \u003cdhowells@redhat.com\u003e\nCc: James E.J. Bottomley \u003cjejb@parisc-linux.org\u003e\nCc: Benjamin Herrenschmidt \u003cbenh@kernel.crashing.org\u003e\nCc: Martin Schwidefsky \u003cschwidefsky@de.ibm.com\u003e\nCc: Paul Mundt \u003clethal@linux-sh.org\u003e\nCc: David S. Miller \u003cdavem@davemloft.net\u003e\nCc: Chris Metcalf \u003ccmetcalf@tilera.com\u003e\nCc: Richard Weinberger \u003crichard@nod.at\u003e\nCc: x86@kernel.org\nAcked-by: Venkatesh Pallipadi \u003cvenki@google.com\u003e\nLink: http://lkml.kernel.org/r/20120420124557.102478630@linutronix.de\n\nChange-Id: Ie2d32789f3a69ee15f38ba704aaa84d6be85bcd4\n"
    },
    {
      "commit": "33d588d0d93e7bf0af4b05420585bfc5df474e63",
      "tree": "3f8cd716316674e2f68e3e4717cb2b2f6a37b5e7",
      "parents": [
        "2e418308459c3a9171f345ba1769bdd0969be97f"
      ],
      "author": {
        "name": "Thomas Gleixner",
        "email": "tglx@linutronix.de",
        "time": "Fri Apr 20 13:05:44 2012 +0000"
      },
      "committer": {
        "name": "Ethan Chen",
        "email": "intervigil@gmail.com",
        "time": "Sat Mar 29 00:49:52 2014 -0700"
      },
      "message": "smp: Add generic smpboot facility\n\nStart a new file, which will hold SMP and CPU hotplug related generic\ninfrastructure.\n\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\nCc: Peter Zijlstra \u003cpeterz@infradead.org\u003e\nCc: Rusty Russell \u003crusty@rustcorp.com.au\u003e\nCc: Paul E. McKenney \u003cpaulmck@linux.vnet.ibm.com\u003e\nCc: Srivatsa S. Bhat \u003csrivatsa.bhat@linux.vnet.ibm.com\u003e\nCc: Matt Turner \u003cmattst88@gmail.com\u003e\nCc: Russell King \u003clinux@arm.linux.org.uk\u003e\nCc: Mike Frysinger \u003cvapier@gentoo.org\u003e\nCc: Jesper Nilsson \u003cjesper.nilsson@axis.com\u003e\nCc: Richard Kuo \u003crkuo@codeaurora.org\u003e\nCc: Tony Luck \u003ctony.luck@intel.com\u003e\nCc: Hirokazu Takata \u003ctakata@linux-m32r.org\u003e\nCc: Ralf Baechle \u003cralf@linux-mips.org\u003e\nCc: David Howells \u003cdhowells@redhat.com\u003e\nCc: James E.J. Bottomley \u003cjejb@parisc-linux.org\u003e\nCc: Benjamin Herrenschmidt \u003cbenh@kernel.crashing.org\u003e\nCc: Martin Schwidefsky \u003cschwidefsky@de.ibm.com\u003e\nCc: Paul Mundt \u003clethal@linux-sh.org\u003e\nCc: David S. Miller \u003cdavem@davemloft.net\u003e\nCc: Chris Metcalf \u003ccmetcalf@tilera.com\u003e\nCc: Richard Weinberger \u003crichard@nod.at\u003e\nCc: x86@kernel.org\nLink: http://lkml.kernel.org/r/20120420124557.035417523@linutronix.de\n\nChange-Id: Ia1ad435435aa12c47ac0d381ae031ebf6edcff1f\n"
    }
  ]
}