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2017-12-11workqueue: remove unneeded kallsyms includeSergey Senozhatsky1-1/+0
The filw was converted from print_symbol() to %pf some time ago (044c782ce3a901fb "workqueue: fix checkpatch issues"). kallsyms does not seem to be needed anymore. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-04workqueue/hotplug: remove the workaround in rebind_workers()Lai Jiangshan1-10/+0
Since the cpu/hotplug refactoring, DOWN_FAILED is never called without preceding DOWN_PREPARE making the workaround unnecessary. Remove it. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-04workqueue/hotplug: simplify workqueue_offline_cpu()Lai Jiangshan1-9/+6
Since the recent cpu/hotplug refactoring, workqueue_offline_cpu() is guaranteed to run on the local cpu which is going offline. This also fixes the following deadlock by removing work item scheduling and flushing from CPU hotplug path. http://lkml.kernel.org/r/1504764252-29091-1-git-send-email-prsood@codeaurora.org tj: Description update. Signed-off-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-11-27workqueue: respect isolated cpus when queueing an unbound workTal Shorer1-1/+6
Initialize wq_unbound_cpumask to exclude cpus that were isolated by the cmdline's isolcpus parameter. Signed-off-by: Tal Shorer <tal.shorer@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-11-21treewide: Remove TIMER_FUNC_TYPE and TIMER_DATA_TYPE castsKees Cook1-1/+1
With all callbacks converted, and the timer callback prototype switched over, the TIMER_FUNC_TYPE cast is no longer needed, so remove it. Conversion was done with the following scripts: perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \ $(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u) perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \ $(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u) The now unused macros are also dropped from include/linux/timer.h. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-11-15Merge branch 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-1/+2
Pull workqueue updates from Tejun Heo: "There was a commit to make unbound kworkers respect cpu isolation but it conflicted with the restructuring of cpu isolation and got reverted, so the only thing left is the trivial comment fix. Will retry the cpu isolation change after this merge window" * 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix comment for unbound workqueue's attrbutes Revert "workqueue: respect isolated cpus when queueing an unbound work" workqueue: respect isolated cpus when queueing an unbound work
2017-11-13Merge branch 'timers-core-for-linus' of ↵Linus Torvalds1-17/+12
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Yet another big pile of changes: - More year 2038 work from Arnd slowly reaching the point where we need to think about the syscalls themself. - A new timer function which allows to conditionally (re)arm a timer only when it's either not running or the new expiry time is sooner than the armed expiry time. This allows to use a single timer for multiple timeout requirements w/o caring about the first expiry time at the call site. - A new NMI safe accessor to clock real time for the printk timestamp work. Can be used by tracing, perf as well if required. - A large number of timer setup conversions from Kees which got collected here because either maintainers requested so or they simply got ignored. As Kees pointed out already there are a few trivial merge conflicts and some redundant commits which was unavoidable due to the size of this conversion effort. - Avoid a redundant iteration in the timer wheel softirq processing. - Provide a mechanism to treat RTC implementations depending on their hardware properties, i.e. don't inflict the write at the 0.5 seconds boundary which originates from the PC CMOS RTC to all RTCs. No functional change as drivers need to be updated separately. - The usual small updates to core code clocksource drivers. Nothing really exciting" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (111 commits) timers: Add a function to start/reduce a timer pstore: Use ktime_get_real_fast_ns() instead of __getnstimeofday() timer: Prepare to change all DEFINE_TIMER() callbacks netfilter: ipvs: Convert timers to use timer_setup() scsi: qla2xxx: Convert timers to use timer_setup() block/aoe: discover_timer: Convert timers to use timer_setup() ide: Convert timers to use timer_setup() drbd: Convert timers to use timer_setup() mailbox: Convert timers to use timer_setup() crypto: Convert timers to use timer_setup() drivers/pcmcia: omap1: Fix error in automated timer conversion ARM: footbridge: Fix typo in timer conversion drivers/sgi-xp: Convert timers to use timer_setup() drivers/pcmcia: Convert timers to use timer_setup() drivers/memstick: Convert timers to use timer_setup() drivers/macintosh: Convert timers to use timer_setup() hwrng/xgene-rng: Convert timers to use timer_setup() auxdisplay: Convert timers to use timer_setup() sparc/led: Convert timers to use timer_setup() mips: ip22/32: Convert timers to use timer_setup() ...
2017-11-08workqueue: Use lockdep to assert IRQs are disabled/enabledFrederic Weisbecker1-1/+1
Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: David S . Miller <davem@davemloft.net> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1509980490-4285-4-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-07Merge branch 'linus' into locking/core, to resolve conflictsIngo Molnar1-22/+15
Conflicts: include/linux/compiler-clang.h include/linux/compiler-gcc.h include/linux/compiler-intel.h include/uapi/linux/stddef.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-11-06workqueue: Fix comment for unbound workqueue's attrbutesWang Long1-1/+2
Signed-off-by: Wang Long <wanglong19@meituan.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-11-03Revert "workqueue: respect isolated cpus when queueing an unbound work"Tejun Heo1-5/+1
This reverts commit b5149873a0c299195b5346fe4dc2c5b04ae2f995. It conflicts with the following isolcpus change from the sched branch. edb9382175c3 ("sched/isolation: Move isolcpus= handling to the housekeeping code") Let's revert for now. Signed-off-by: Tejun Heo <tj@kernel.org>
2017-10-25workqueue: Remove now redundant lock acquisitions wrt. workqueue flushesByungchul Park1-16/+3
The workqueue code added manual lock acquisition annotations to catch deadlocks. After lockdepcrossrelease was introduced, some of those became redundant, since wait_for_completion() already does the acquisition and tracking. Remove the duplicate annotations. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: amir73il@gmail.com Cc: axboe@kernel.dk Cc: darrick.wong@oracle.com Cc: david@fromorbit.com Cc: hch@infradead.org Cc: idryomov@gmail.com Cc: johan@kernel.org Cc: johannes.berg@intel.com Cc: kernel-team@lge.com Cc: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/1508921765-15396-9-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25locking/atomics, workqueue: Convert ACCESS_ONCE() to READ_ONCE()/WRITE_ONCE()Mark Rutland1-2/+2
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't currently harmful. However, for some features it is necessary to instrument reads and writes separately, which is not possible with ACCESS_ONCE(). This distinction is critical to correct operation. It's possible to transform the bulk of kernel code using the Coccinelle script below. However, this doesn't handle comments, leaving references to ACCESS_ONCE() instances which have been removed. As a preparatory step, this patch converts the workqueue code and comments to use {READ,WRITE}_ONCE() consistently. ---- virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-12-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-21workqueue: respect isolated cpus when queueing an unbound workTal Shorer1-1/+5
Initialize wq_unbound_cpumask to exclude cpus that were isolated by the cmdline's isolcpus parameter. Signed-off-by: Tal Shorer <tal.shorer@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-10-18workqueue: Convert timers to use timer_setup() (part 2)Kees Cook1-8/+6
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. (The prior workqueue patch missed a few timers.) Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Link: https://lkml.kernel.org/r/20171016225825.GA99101@beast Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-10-10workqueue: replace pool->manager_arb mutex with a flagTejun Heo1-22/+15
Josef reported a HARDIRQ-safe -> HARDIRQ-unsafe lock order detected by lockdep: [ 1270.472259] WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected [ 1270.472783] 4.14.0-rc1-xfstests-12888-g76833e8 #110 Not tainted [ 1270.473240] ----------------------------------------------------- [ 1270.473710] kworker/u5:2/5157 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 1270.474239] (&(&lock->wait_lock)->rlock){+.+.}, at: [<ffffffff8da253d2>] __mutex_unlock_slowpath+0xa2/0x280 [ 1270.474994] [ 1270.474994] and this task is already holding: [ 1270.475440] (&pool->lock/1){-.-.}, at: [<ffffffff8d2992f6>] worker_thread+0x366/0x3c0 [ 1270.476046] which would create a new lock dependency: [ 1270.476436] (&pool->lock/1){-.-.} -> (&(&lock->wait_lock)->rlock){+.+.} [ 1270.476949] [ 1270.476949] but this new dependency connects a HARDIRQ-irq-safe lock: [ 1270.477553] (&pool->lock/1){-.-.} ... [ 1270.488900] to a HARDIRQ-irq-unsafe lock: [ 1270.489327] (&(&lock->wait_lock)->rlock){+.+.} ... [ 1270.494735] Possible interrupt unsafe locking scenario: [ 1270.494735] [ 1270.495250] CPU0 CPU1 [ 1270.495600] ---- ---- [ 1270.495947] lock(&(&lock->wait_lock)->rlock); [ 1270.496295] local_irq_disable(); [ 1270.496753] lock(&pool->lock/1); [ 1270.497205] lock(&(&lock->wait_lock)->rlock); [ 1270.497744] <Interrupt> [ 1270.497948] lock(&pool->lock/1); , which will cause a irq inversion deadlock if the above lock scenario happens. The root cause of this safe -> unsafe lock order is the mutex_unlock(pool->manager_arb) in manage_workers() with pool->lock held. Unlocking mutex while holding an irq spinlock was never safe and this problem has been around forever but it never got noticed because the only time the mutex is usually trylocked while holding irqlock making actual failures very unlikely and lockdep annotation missed the condition until the recent b9c16a0e1f73 ("locking/mutex: Fix lockdep_assert_held() fail"). Using mutex for pool->manager_arb has always been a bit of stretch. It primarily is an mechanism to arbitrate managership between workers which can easily be done with a pool flag. The only reason it became a mutex is that pool destruction path wants to exclude parallel managing operations. This patch replaces the mutex with a new pool flag POOL_MANAGER_ACTIVE and make the destruction path wait for the current manager on a wait queue. v2: Drop unnecessary flag clearing before pool destruction as suggested by Boqun. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: stable@vger.kernel.org
2017-10-05workqueue: Convert callback to use from_timer()Kees Cook1-4/+3
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch workqueue to use from_timer() and pass the timer pointer explicitly. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Cc: Petr Mladek <pmladek@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: linux-s390@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ursula Braun <ubraun@linux.vnet.ibm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Harish Patil <harish.patil@cavium.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Manish Chopra <manish.chopra@cavium.com> Cc: Len Brown <len.brown@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-pm@vger.kernel.org Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mark Gross <mark.gross@intel.com> Cc: linux-watchdog@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Michael Reed <mdr@sgi.com> Cc: netdev@vger.kernel.org Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lkml.kernel.org/r/1507159627-127660-14-git-send-email-keescook@chromium.org
2017-10-05timer: Remove users of TIMER_DEFERRED_INITIALIZERKees Cook1-5/+3
This removes uses of TIMER_DEFERRED_INITIALIZER and chooses a location to call timer_setup() from before add_timer() or mod_timer() is called. Adjusts callbacks to use from_timer() as needed. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mips@linux-mips.org Cc: Petr Mladek <pmladek@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: linux1394-devel@lists.sourceforge.net Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: linux-s390@vger.kernel.org Cc: linux-wireless@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Ursula Braun <ubraun@linux.vnet.ibm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Harish Patil <harish.patil@cavium.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Manish Chopra <manish.chopra@cavium.com> Cc: Len Brown <len.brown@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: linux-pm@vger.kernel.org Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Julian Wiedmann <jwi@linux.vnet.ibm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Mark Gross <mark.gross@intel.com> Cc: linux-watchdog@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Michael Reed <mdr@sgi.com> Cc: netdev@vger.kernel.org Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lkml.kernel.org/r/1507159627-127660-7-git-send-email-keescook@chromium.org
2017-09-06Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-3/+3
Pull workqueue updates from Tejun Heo: "Nothing major. I introduced a flag collsion bug during v4.13 cycle which is fixed in this pull request. Fortunately, the flag is for debugging / verification and the bug isn't critical" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix flag collision workqueue: Use TASK_IDLE workqueue: fix path to documentation workqueue: doc change for ST behavior on NUMA systems
2017-09-05Merge branch 'for-4.13-fixes' into for-4.14Tejun Heo1-4/+26
2017-08-29locking/lockdep: Untangle xhlock history save/restore from task independencePeter Zijlstra1-5/+4
Where XHLOCK_{SOFT,HARD} are save/restore points in the xhlocks[] to ensure the temporal IRQ events don't interact with task state, the XHLOCK_PROC is a fundament different beast that just happens to share the interface. The purpose of XHLOCK_PROC is to annotate independent execution inside one task. For example workqueues, each work should appear to run in its own 'pristine' 'task'. Remove XHLOCK_PROC in favour of its own interface to avoid confusion. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boqun.feng@gmail.com Cc: david@fromorbit.com Cc: johannes@sipsolutions.net Cc: kernel-team@lge.com Cc: oleg@redhat.com Cc: tj@kernel.org Link: http://lkml.kernel.org/r/20170829085939.ggmb6xiohw67micb@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25locking/lockdep: Fix workqueue crossrelease annotationPeter Zijlstra1-1/+22
The new completion/crossrelease annotations interact unfavourable with the extant flush_work()/flush_workqueue() annotations. The problem is that when a single work class does: wait_for_completion(&C) and complete(&C) in different executions, we'll build dependencies like: lock_map_acquire(W) complete_acquire(C) and lock_map_acquire(W) complete_release(C) which results in the dependency chain: W->C->W, which lockdep thinks spells deadlock, even though there is no deadlock potential since works are ran concurrently. One possibility would be to change the work 'lock' to recursive-read, but that would mean hitting a lockdep limitation on recursive locks. Also, unconditinoally switching to recursive-read here would fail to detect the actual deadlock on single-threaded workqueues, which do have a problem with this. For now, forcefully disregard these locks for crossrelease. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boqun.feng@gmail.com Cc: byungchul.park@lge.com Cc: david@fromorbit.com Cc: johannes@sipsolutions.net Cc: oleg@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-25workqueue/lockdep: 'Fix' flush_work() annotationPeter Zijlstra1-9/+11
The flush_work() annotation as introduced by commit: e159489baa71 ("workqueue: relax lockdep annotation on flush_work()") hits on the lockdep problem with recursive read locks. The situation as described is: Work W1: Work W2: Task: ARR(Q) ARR(Q) flush_workqueue(Q) A(W1) A(W2) A(Q) flush_work(W2) R(Q) A(W2) R(W2) if (special) A(Q) else ARR(Q) R(Q) where: A - acquire, ARR - acquire-read-recursive, R - release. Where under 'special' conditions we want to trigger a lock recursion deadlock, but otherwise allow the flush_work(). The allowing is done by using recursive read locks (ARR), but lockdep is broken for recursive stuff. However, there appears to be no need to acquire the lock if we're not 'special', so if we remove the 'else' clause things become much simpler and no longer need the recursion thing at all. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boqun.feng@gmail.com Cc: byungchul.park@lge.com Cc: david@fromorbit.com Cc: johannes@sipsolutions.net Cc: oleg@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-23workqueue: Use TASK_IDLEPeter Zijlstra1-2/+2
Workqueues don't use signals, it (ab)uses TASK_INTERRUPTIBLE to avoid increasing the loadavg numbers. We've 'recently' introduced TASK_IDLE for this case: 80ed87c8a9ca ("sched/wait: Introduce TASK_NOLOAD and TASK_IDLE") use it. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-08-17locking/lockdep: Explicitly initialize wq_barrier::done::mapBoqun Feng1-1/+10
With the new lockdep crossrelease feature, which checks completions usage, a false positive is reported in the workqueue code: > Worker A : acquired of wfc.work -> wait for cpu_hotplug_lock to be released > Task B : acquired of cpu_hotplug_lock -> wait for lock#3 to be released > Task C : acquired of lock#3 -> wait for completion of barr->done > (Task C is in lru_add_drain_all_cpuslocked()) > Worker D : wait for wfc.work to be released -> will complete barr->done Such a dead lock can not happen because Task C's barr->done and Worker D's barr->done can not be the same instance. The reason of this false positive is we initialize all wq_barrier::done at insert_wq_barrier() via init_completion(), which makes them belong to the same lock class, therefore, impossible circles are reported. To fix this, explicitly initialize the lockdep map for wq_barrier::done in insert_wq_barrier(), so that the lock class key of wq_barrier::done is a subkey of the corresponding work_struct, as a result we won't build a dependency between a wq_barrier with a unrelated work, and we can differ wq barriers based on the related works, so the false positive above is avoided. Also define the empty lockdep_init_map_crosslock() for !CROSSRELEASE to make the code simple and away from unnecessary #ifdefs. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170817094622.12915-1-boqun.feng@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-10locking/lockdep: Implement the 'crossrelease' featureByungchul Park1-0/+2
Lockdep is a runtime locking correctness validator that detects and reports a deadlock or its possibility by checking dependencies between locks. It's useful since it does not report just an actual deadlock but also the possibility of a deadlock that has not actually happened yet. That enables problems to be fixed before they affect real systems. However, this facility is only applicable to typical locks, such as spinlocks and mutexes, which are normally released within the context in which they were acquired. However, synchronization primitives like page locks or completions, which are allowed to be released in any context, also create dependencies and can cause a deadlock. So lockdep should track these locks to do a better job. The 'crossrelease' implementation makes these primitives also be tracked. Signed-off-by: Byungchul Park <byungchul.park@lge.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: boqun.feng@gmail.com Cc: kernel-team@lge.com Cc: kirill@shutemov.name Cc: npiggin@gmail.com Cc: walken@google.com Cc: willy@infradead.org Link: http://lkml.kernel.org/r/1502089981-21272-6-git-send-email-byungchul.park@lge.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-07workqueue: fix path to documentationBenjamin Peterson1-1/+1
Signed-off-by: Benjamin Peterson <bp@benjamin.pe> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-28workqueue: Work around edge cases for calc of pool's cpumaskMichael Bringmann1-0/+7
There is an underlying assumption/trade-off in many layers of the Linux system that CPU <-> node mapping is static. This is despite the presence of features like NUMA and 'hotplug' that support the dynamic addition/ removal of fundamental system resources like CPUs and memory. PowerPC systems, however, do provide extensive features for the dynamic change of resources available to a system. Currently, there is little or no synchronization protection around the updating of the CPU <-> node mapping, and the export/update of this information for other layers / modules. In systems which can change this mapping during 'hotplug', like PowerPC, the information is changing underneath all layers that might reference it. This patch attempts to ensure that a valid, usable cpumask attribute is used by the workqueue infrastructure when setting up new resource pools. It prevents a crash that has been observed when an 'empty' cpumask is passed along to the worker/task scheduling code. It is intended as a temporary workaround until a more fundamental review and correction of the issue can be done. [With additions to the patch provided by Tejun Hao <tj@kernel.org>] Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-07-25workqueue: implicit ordered attribute should be overridableTejun Heo1-4/+9
5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered") automatically enabled ordered attribute for unbound workqueues w/ max_active == 1. Because ordered workqueues reject max_active and some attribute changes, this implicit ordered mode broke cases where the user creates an unbound workqueue w/ max_active == 1 and later explicitly changes the related attributes. This patch distinguishes explicit and implicit ordered setting and overrides from attribute changes if implict. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
2017-07-19workqueue: restore WQ_UNBOUND/max_active==1 to be orderedTejun Heo1-0/+10
The combination of WQ_UNBOUND and max_active == 1 used to imply ordered execution. After NUMA affinity 4c16bd327c74 ("workqueue: implement NUMA affinity for unbound workqueues"), this is no longer true due to per-node worker pools. While the right way to create an ordered workqueue is alloc_ordered_workqueue(), the documentation has been misleading for a long time and people do use WQ_UNBOUND and max_active == 1 for ordered workqueues which can lead to subtle bugs which are very difficult to trigger. It's unlikely that we'd see noticeable performance impact by enforcing ordering on WQ_UNBOUND / max_active == 1 workqueues. Let's automatically set __WQ_ORDERED for those workqueues. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Christoph Hellwig <hch@infradead.org> Reported-by: Alexei Potashnik <alexei@purestorage.com> Fixes: 4c16bd327c74 ("workqueue: implement NUMA affinity for unbound workqueues") Cc: stable@vger.kernel.org # v3.10+
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar1-2/+2
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-01Merge branch 'sched-core-for-linus' of ↵Linus Torvalds1-0/+23
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - another round of rq-clock handling debugging, robustization and fixes - PELT accounting improvements - CPU hotplug related ->cpus_allowed affinity handling fixes all around the tree - ... plus misc fixes, cleanups and updates" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) sched/x86: Update reschedule warning text crypto: N2 - Replace racy task affinity logic cpufreq/sparc-us2e: Replace racy task affinity logic cpufreq/sparc-us3: Replace racy task affinity logic cpufreq/sh: Replace racy task affinity logic cpufreq/ia64: Replace racy task affinity logic ACPI/processor: Replace racy task affinity logic ACPI/processor: Fix error handling in __acpi_processor_start() sparc/sysfs: Replace racy task affinity logic powerpc/smp: Replace open coded task affinity logic ia64/sn/hwperf: Replace racy task affinity logic ia64/salinfo: Replace racy task affinity logic workqueue: Provide work_on_cpu_safe() ia64/topology: Remove cpus_allowed manipulation sched/fair: Move the PELT constants into a generated header sched/fair: Increase PELT accuracy for small tasks sched/fair: Fix comments sched/Documentation: Add 'sched-pelt' tool sched/fair: Fix corner case in __accumulate_sum() sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags() ...
2017-05-01Merge branch 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds1-3/+2
Pull workqueue update from Tejun Heo: "One trivial patch to use setup_deferrable_timer() instead of open-coding the initialization" * 'for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: use setup_deferrable_timer
2017-04-15workqueue: Provide work_on_cpu_safe()Thomas Gleixner1-0/+23
work_on_cpu() is not protected against CPU hotplug. For code which requires to be either executed on an online CPU or to fail if the CPU is not available the callsite would have to protect against CPU hotplug. Provide a function which does get/put_online_cpus() around the call to work_on_cpu() and fails the call with -ENODEV if the target CPU is not online. Preparatory patch to convert several racy task affinity manipulations. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/20170412201042.262610721@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-03-06workqueue: use setup_deferrable_timerGeliang Tang1-3/+2
Use setup_deferrable_timer() instead of init_timer_deferrable() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-03-06workqueue: trigger WARN if queue_delayed_work() is called with NULL @wqTejun Heo1-0/+1
If queue_delayed_work() gets called with NULL @wq, the kernel will oops asynchronuosly on timer expiration which isn't too helpful in tracking down the offender. This actually happened with smc. __queue_delayed_work() already does several input sanity checks synchronously. Add NULL @wq check. Reported-by: Dave Jones <davej@codemonkey.org.uk> Link: http://lkml.kernel.org/r/20170227171439.jshx3qplflyrgcv7@codemonkey.org.uk Signed-off-by: Tejun Heo <tj@kernel.org>
2017-02-10time: Remove CONFIG_TIMER_STATSKees Cook1-2/+0
Currently CONFIG_TIMER_STATS exposes process information across namespaces: kernel/time/timer_list.c print_timer(): SEQ_printf(m, ", %s/%d", tmp, timer->start_pid); /proc/timer_list: #11: <0000000000000000>, hrtimer_wakeup, S:01, do_nanosleep, cron/2570 Given that the tracer can give the same information, this patch entirely removes CONFIG_TIMER_STATS. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: linux-doc@vger.kernel.org Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Xing Gao <xgao01@email.wm.edu> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jessica Frazelle <me@jessfraz.com> Cc: kernel-hardening@lists.openwall.com Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Michal Marek <mmarek@suse.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Olof Johansson <olof@lixom.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-api@vger.kernel.org Cc: Arjan van de Ven <arjan@linux.intel.com> Link: http://lkml.kernel.org/r/20170208192659.GA32582@beast Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-19Merge branch 'for-4.9' into for-4.10Tejun Heo1-18/+85
2016-10-19workqueue: move wq_numa_init() to workqueue_init()Tejun Heo1-2/+23
While splitting up workqueue initialization into two parts, ac8f73400782 ("workqueue: make workqueue available early during boot") put wq_numa_init() into workqueue_init_early(). Unfortunately, on some archs including power and arm64, cpu to node mapping isn't yet established by the time the early init is called leading to incorrect NUMA initialization and subsequently the following oops due to zero cpumask on node-specific unbound pools. Unable to handle kernel paging request for data at address 0x00000038 Faulting instruction address: 0xc0000000000fc0cc Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-compiler_gcc-6.2.0-next-20161005 #94 task: c0000007f5400000 task.stack: c000001ffc084000 NIP: c0000000000fc0cc LR: c0000000000ed928 CTR: c0000000000fbfd0 REGS: c000001ffc087780 TRAP: 0300 Not tainted (4.8.0-compiler_gcc-6.2.0-next-20161005) MSR: 9000000002009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE> CR: 48000424 XER: 00000000 CFAR: c0000000000089dc DAR: 0000000000000038 DSISR: 40000000 SOFTE: 0 GPR00: c0000000000ed928 c000001ffc087a00 c000000000e63200 c000000010d6d600 GPR04: c0000007f5409200 0000000000000021 000000000748e08c 000000000000001f GPR08: 0000000000000000 0000000000000021 000000000748f1f8 0000000000000000 GPR12: 0000000028000422 c00000000fb80000 c00000000000e0c8 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000021 0000000000000001 GPR20: ffffffffafb50401 0000000000000000 c000000010d6d600 000000000000ba7e GPR24: 000000000000ba7e c000000000d8bc58 afb504000afb5041 0000000000000001 GPR28: 0000000000000000 0000000000000004 c0000007f5409280 0000000000000000 NIP [c0000000000fc0cc] enqueue_task_fair+0xfc/0x18b0 LR [c0000000000ed928] activate_task+0x78/0xe0 Call Trace: [c000001ffc087a00] [c0000007f5409200] 0xc0000007f5409200 (unreliable) [c000001ffc087b10] [c0000000000ed928] activate_task+0x78/0xe0 [c000001ffc087b50] [c0000000000ede58] ttwu_do_activate+0x68/0xc0 [c000001ffc087b90] [c0000000000ef1b8] try_to_wake_up+0x208/0x4f0 [c000001ffc087c10] [c0000000000d3484] create_worker+0x144/0x250 [c000001ffc087cb0] [c000000000cd72d0] workqueue_init+0x124/0x150 [c000001ffc087d00] [c000000000cc0e74] kernel_init_freeable+0x158/0x360 [c000001ffc087dc0] [c00000000000e0e4] kernel_init+0x24/0x160 [c000001ffc087e30] [c00000000000bfa0] ret_from_kernel_thread+0x5c/0xbc Instruction dump: 62940401 3b800000 3aa00000 7f17c378 3a600001 3b600001 60000000 60000000 60420000 72490021 ebfe0150 2f890001 <ebbf0038> 419e0de0 7fbee840 419e0e58 ---[ end trace 0000000000000000 ]--- Fix it by moving wq_numa_init() to workqueue_init(). As this means that the early intialization may not have full NUMA info for per-cpu pools and ignores NUMA affinity for unbound pools, fix them up from workqueue_init() after wq_numa_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Link: http://lkml.kernel.org/r/87twck5wqo.fsf@concordia.ellerman.id.au Fixes: ac8f73400782 ("workqueue: make workqueue available early during boot") Signed-off-by: Tejun Heo <tj@kernel.org>
2016-10-11kthread: rename probe_kthread_data() to kthread_probe_data()Petr Mladek1-1/+1
Patch series "kthread: Kthread worker API improvements" The intention of this patchset is to make it easier to manipulate and maintain kthreads. Especially, I want to replace all the custom main cycles with a generic one. Also I want to make the kthreads sleep in a consistent state in a common place when there is no work. This patch (of 11): A good practice is to prefix the names of functions by the name of the subsystem. This patch fixes the name of probe_kthread_data(). The other wrong functions names are part of the kthread worker API and will be fixed separately. Link: http://lkml.kernel.org/r/1470754545-17632-2-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-17workqueue: remove keventd_up()Tejun Heo1-1/+1
keventd_up() no longer has in-kernel users. Remove it and make wq_online static. Signed-off-by: Tejun Heo <tj@kernel.org>
2016-09-17workqueue: make workqueue available early during bootTejun Heo1-16/+60
Workqueue is currently initialized in an early init call; however, there are cases where early boot code has to be split and reordered to come after workqueue initialization or the same code path which makes use of workqueues is used both before workqueue initailization and after. The latter cases have to gate workqueue usages with keventd_up() tests, which is nasty and easy to get wrong. Workqueue usages have become widespread and it'd be a lot more convenient if it can be used very early from boot. This patch splits workqueue initialization into two steps. workqueue_init_early() which sets up the basic data structures so that workqueues can be created and work items queued, and workqueue_init() which actually brings up workqueues online and starts executing queued work items. The former step can be done very early during boot once memory allocation, cpumasks and idr are initialized. The latter right after kthreads become available. This allows work item queueing and canceling from very early boot which is what most of these use cases want. * As systemd_wq being initialized doesn't indicate that workqueue is fully online anymore, update keventd_up() to test wq_online instead. The follow-up patches will get rid of all its usages and the function itself. * Flushing doesn't make sense before workqueue is fully initialized. The flush functions trigger WARN and return immediately before fully online. * Work items are never in-flight before fully online. Canceling can always succeed by skipping the flush step. * Some code paths can no longer assume to be called with irq enabled as irq is disabled during early boot. Use irqsave/restore operations instead. v2: Watchdog init, which requires timer to be running, moved from workqueue_init_early() to workqueue_init(). Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/CA+55aFx0vPuMuxn00rBSM192n-Du5uxy+4AvKa0SBSOVJeuCGg@mail.gmail.com
2016-09-16workqueue: dump workqueue state on sanity check failures in destroy_workqueue()Tejun Heo1-0/+2
destroy_workqueue() performs a number of sanity checks to ensure that the workqueue is empty before proceeding with destruction. However, it's not always easy to tell what's going on just from the warning message. Let's dump workqueue state after sanity check failures to help debugging. Signed-off-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/CACT4Y+Zs6vkjHo9qHb4TrEiz3S4+quvvVQ9VWvj2Mx6pETGb9Q@mail.gmail.com Cc: Dmitry Vyukov <dvyukov@google.com>
2016-08-29workqueue: add cancel_work()Jens Axboe1-14/+26
Like cancel_delayed_work(), but for regular work. Signed-off-by: Jens Axboe <axboe@fb.com> Mehed-by: Tejun Heo <tj@kernel.org> Acked-by: Tejun Heo <tj@kernel.org>
2016-07-29Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds1-65/+43
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug updates from Thomas Gleixner: "This is the next part of the hotplug rework. - Convert all notifiers with a priority assigned - Convert all CPU_STARTING/DYING notifiers The final removal of the STARTING/DYING infrastructure will happen when the merge window closes. Another 700 hundred line of unpenetrable maze gone :)" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits) timers/core: Correct callback order during CPU hot plug leds/trigger/cpu: Move from CPU_STARTING to ONLINE level powerpc/numa: Convert to hotplug state machine arm/perf: Fix hotplug state machine conversion irqchip/armada: Avoid unused function warnings ARC/time: Convert to hotplug state machine clocksource/atlas7: Convert to hotplug state machine clocksource/armada-370-xp: Convert to hotplug state machine clocksource/exynos_mct: Convert to hotplug state machine clocksource/arm_global_timer: Convert to hotplug state machine rcu: Convert rcutree to hotplug state machine KVM/arm/arm64/vgic-new: Convert to hotplug state machine smp/cfd: Convert core to hotplug state machine x86/x2apic: Convert to CPU hotplug state machine profile: Convert to hotplug state machine timers/core: Convert to hotplug state machine hrtimer: Convert to hotplug state machine x86/tboot: Convert to hotplug state machine arm64/armv8 deprecated: Convert to hotplug state machine hwtracing/coresight-etm4x: Convert to hotplug state machine ...
2016-07-25Merge branches 'pm-sleep' and 'pm-tools'Rafael J. Wysocki1-2/+2
* pm-sleep: PM / hibernate: Introduce test_resume mode for hibernation x86 / hibernate: Use hlt_play_dead() when resuming from hibernation PM / hibernate: Image data protection during restoration PM / hibernate: Add missing braces in __register_nosave_region() PM / hibernate: Clean up comments in snapshot.c PM / hibernate: Clean up function headers in snapshot.c PM / hibernate: Add missing braces in hibernate_setup() PM / hibernate: Recycle safe pages after image restoration PM / hibernate: Simplify mark_unsafe_pages() PM / hibernate: Do not free preallocated safe pages during image restore PM / suspend: show workqueue state in suspend flow PM / sleep: make PM notifiers called symmetrically PM / sleep: Make pm_prepare_console() return void PM / Hibernate: Don't let kasan instrument snapshot.c * pm-tools: PM / tools: scripts: AnalyzeSuspend v4.2 tools/turbostat: allow user to alter DESTDIR and PREFIX
2016-07-14workqueue: Convert to state machine callbacksThomas Gleixner1-65/+43
Get rid of the prio ordering of the separate notifiers and use a proper state callback pair. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153335.197083890@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-02PM / suspend: show workqueue state in suspend flowRoger Lu1-2/+2
If freezable workqueue aborts suspend flow, show workqueue state for debug purpose. Signed-off-by: Roger Lu <roger.lu@mediatek.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-16workqueue: Fix setting affinity of unbound worker threadsPeter Zijlstra1-5/+1
With commit e9d867a67fd03ccc ("sched: Allow per-cpu kernel threads to run on online && !active"), __set_cpus_allowed_ptr() expects that only strict per-cpu kernel threads can have affinity to an online CPU which is not yet active. This assumption is currently broken in the CPU_ONLINE notification handler for the workqueues where restore_unbound_workers_cpumask() calls set_cpus_allowed_ptr() when the first cpu in the unbound worker's pool->attr->cpumask comes online. Since set_cpus_allowed_ptr() is called with pool->attr->cpumask in which only one CPU is online which is not yet active, we get the following WARN_ON during an CPU online operation. ------------[ cut here ]------------ WARNING: CPU: 40 PID: 248 at kernel/sched/core.c:1166 __set_cpus_allowed_ptr+0x228/0x2e0 Modules linked in: CPU: 40 PID: 248 Comm: cpuhp/40 Not tainted 4.6.0-autotest+ #4 <..snip..> Call Trace: [c000000f273ff920] [c00000000010493c] __set_cpus_allowed_ptr+0x2cc/0x2e0 (unreliable) [c000000f273ffac0] [c0000000000ed4b0] workqueue_cpu_up_callback+0x2c0/0x470 [c000000f273ffb70] [c0000000000f5c58] notifier_call_chain+0x98/0x100 [c000000f273ffbc0] [c0000000000c5ed0] __cpu_notify+0x70/0xe0 [c000000f273ffc00] [c0000000000c6028] notify_online+0x38/0x50 [c000000f273ffc30] [c0000000000c5214] cpuhp_invoke_callback+0x84/0x250 [c000000f273ffc90] [c0000000000c562c] cpuhp_up_callbacks+0x5c/0x120 [c000000f273ffce0] [c0000000000c64d4] cpuhp_thread_fun+0x184/0x1c0 [c000000f273ffd20] [c0000000000fa050] smpboot_thread_fn+0x290/0x2a0 [c000000f273ffd80] [c0000000000f45b0] kthread+0x110/0x130 [c000000f273ffe30] [c000000000009570] ret_from_kernel_thread+0x5c/0x6c ---[ end trace 00f1456578b2a3b2 ]--- This patch fixes this by limiting the mask to the intersection of the pool affinity and online CPUs. Changelog-cribbed-from: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-19debugobjects: insulate non-fixup logic related to static obj from fixup ↵Du, Changbin1-34/+8
callbacks When activating a static object we need make sure that the object is tracked in the object tracker. If it is a non-static object then the activation is illegal. In previous implementation, each subsystem need take care of this in their fixup callbacks. Actually we can put it into debugobjects core. Thus we can save duplicated code, and have *pure* fixup callbacks. To achieve this, a new callback "is_static_object" is introduced to let the type specific code decide whether a object is static or not. If yes, we take it into object tracker, otherwise give warning and invoke fixup callback. This change has paassed debugobjects selftest, and I also do some test with all debugobjects supports enabled. At last, I have a concern about the fixups that can it change the object which is in incorrect state on fixup? Because the 'addr' may not point to any valid object if a non-static object is not tracked. Then Change such object can overwrite someone's memory and cause unexpected behaviour. For example, the timer_fixup_activate bind timer to function stub_timer. Link: http://lkml.kernel.org/r/1462576157-14539-1-git-send-email-changbin.du@intel.com [changbin.du@intel.com: improve code comments where invoke the new is_static_object callback] Link: http://lkml.kernel.org/r/1462777431-8171-1-git-send-email-changbin.du@intel.com Signed-off-by: Du, Changbin <changbin.du@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Triplett <josh@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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