linux/kernel/workqueue.c, branch v5.6

workqueue: don't use wq_select_unbound_cpu() for bound works

2020-03-10T14:30:51Z

wq_select_unbound_cpu() is designed for unbound workqueues only, but it's wrongly called when using a bound workqueue too. Fixing this ensures work queued to a bound workqueue with cpu=WORK_CPU_UNBOUND always runs on the local CPU. Before, that would happen only if wq_unbound_cpumask happened to include it (likely almost always the case), or was empty, or we got lucky with forced round-robin placement. So restricting /sys/devices/virtual/workqueue/cpumask to a small subset of a machine's CPUs would cause some bound work items to run unexpectedly there. Fixes: ef557180447f ("workqueue: schedule WORK_CPU_UNBOUND work on wq_unbound_cpumask CPUs") Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Hillf Danton [dj: massage changelog] Signed-off-by: Daniel Jordan Cc: Tejun Heo Cc: Lai Jiangshan Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-01-28T18:07:09Z

Pull scheduler updates from Ingo Molnar: "These were the main changes in this cycle: - More -rt motivated separation of CONFIG_PREEMPT and CONFIG_PREEMPTION. - Add more low level scheduling topology sanity checks and warnings to filter out nonsensical topologies that break scheduling. - Extend uclamp constraints to influence wakeup CPU placement - Make the RT scheduler more aware of asymmetric topologies and CPU capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y - Make idle CPU selection more consistent - Various fixes, smaller cleanups, updates and enhancements - please see the git log for details" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits) sched/fair: Define sched_idle_cpu() only for SMP configurations sched/topology: Assert non-NUMA topology masks don't (partially) overlap idle: fix spelling mistake "iterrupts" -> "interrupts" sched/fair: Remove redundant call to cpufreq_update_util() sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP sched/fair: calculate delta runnable load only when it's needed sched/cputime: move rq parameter in irqtime_account_process_tick stop_machine: Make stop_cpus() static sched/debug: Reset watchdog on all CPUs while processing sysrq-t sched/core: Fix size of rq::uclamp initialization sched/uclamp: Fix a bug in propagating uclamp value in new cgroups sched/fair: Load balance aggressively for SCHED_IDLE CPUs sched/fair : Improve update_sd_pick_busiest for spare capacity case watchdog: Remove soft_lockup_hrtimer_cnt and related code sched/rt: Make RT capacity-aware sched/fair: Make EAS wakeup placement consider uclamp restrictions sched/fair: Make task_fits_capacity() consider uclamp restrictions sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with() sched/uclamp: Make uclamp util helpers use and return UL values ...

workqueue: add worker function to workqueue_execute_end tracepoint

2020-01-15T16:02:47Z

It's surprising that workqueue_execute_end includes only the work when its counterpart workqueue_execute_start has both the work and the worker function. You can't set a tracing filter or trigger based on the function, and postprocessing scripts interested in specific functions are harder to write since they have to remember the work from _start and match it up with the same field in _end. Add the function name, taking care to use the copy stashed in the worker since the work is no longer safe to touch. Signed-off-by: Daniel Jordan Cc: Tejun Heo Cc: Lai Jiangshan Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo

Merge tag 'v5.5-rc3' into sched/core, to pick up fixes

2019-12-25T09:41:37Z

Signed-off-by: Ingo Molnar

sched/rt, workqueue: Use PREEMPTION

2019-12-08T13:37:37Z

CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Update the comment to use PREEMPTION because it is true for both preemption models. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: Lai Jiangshan Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Tejun Heo Link: https://lore.kernel.org/r/20191015191821.11479-35-bigeasy@linutronix.de Signed-off-by: Ingo Molnar

workqueue: Use pr_warn instead of pr_warning

2019-12-06T08:59:30Z

Use pr_warn() instead of the remaining pr_warning() calls. Link: http://lkml.kernel.org/r/20191128004752.35268-2-wangkefeng.wang@huawei.com To: joe@perches.com To: linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org Cc: tj@kernel.org Cc: arnd@arndb.de Cc: sergey.senozhatsky@gmail.com Cc: rostedt@goodmis.org Signed-off-by: Kefeng Wang Acked-by: Tejun Heo Signed-off-by: Petr Mladek

Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-26T23:42:43Z

Pull RCU updates from Ingo Molnar: "The main changes in this cycle were: - Dynamic tick (nohz) updates, perhaps most notably changes to force the tick on when needed due to lengthy in-kernel execution on CPUs on which RCU is waiting. - Linux-kernel memory consistency model updates. - Replace rcu_swap_protected() with rcu_prepace_pointer(). - Torture-test updates. - Documentation updates. - Miscellaneous fixes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) security/safesetid: Replace rcu_swap_protected() with rcu_replace_pointer() net/sched: Replace rcu_swap_protected() with rcu_replace_pointer() net/netfilter: Replace rcu_swap_protected() with rcu_replace_pointer() net/core: Replace rcu_swap_protected() with rcu_replace_pointer() bpf/cgroup: Replace rcu_swap_protected() with rcu_replace_pointer() fs/afs: Replace rcu_swap_protected() with rcu_replace_pointer() drivers/scsi: Replace rcu_swap_protected() with rcu_replace_pointer() drm/i915: Replace rcu_swap_protected() with rcu_replace_pointer() x86/kvm/pmu: Replace rcu_swap_protected() with rcu_replace_pointer() rcu: Upgrade rcu_swap_protected() to rcu_replace_pointer() rcu: Suppress levelspread uninitialized messages rcu: Fix uninitialized variable in nocb_gp_wait() rcu: Update descriptions for rcu_future_grace_period tracepoint rcu: Update descriptions for rcu_nocb_wake tracepoint rcu: Remove obsolete descriptions for rcu_barrier tracepoint rcu: Ensure that ->rcu_urgent_qs is set before resched IPI workqueue: Convert for_each_wq to use built-in list check rcu: Several rcu_segcblist functions can be static rcu: Remove unused function hlist_bl_del_init_rcu() Documentation: Rename rcu_node_context_switch() to rcu_note_context_switch() ...

workqueue: Add RCU annotation for pwq list walk

2019-11-15T19:53:35Z

An additional check has been recently added to ensure that a RCU related lock is held while the RCU list is iterated. The `pwqs' are sometimes iterated without a RCU lock but with the &wq->mutex acquired leading to a warning. Teach list_for_each_entry_rcu() that the RCU usage is okay if &wq->mutex is acquired during the list traversal. Fixes: 28875945ba98d ("rcu: Add support for consolidated-RCU reader checking") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tejun Heo

workqueue: Convert for_each_wq to use built-in list check

2019-10-30T15:34:10Z

Because list_for_each_entry_rcu() can now check for holding a lock as well as for being in an RCU read-side critical section, this commit replaces the workqueue_sysfs_unregister() function's use of assert_rcu_or_wq_mutex() and list_for_each_entry_rcu() with list_for_each_entry_rcu() augmented with a lockdep_is_held() optional argument. Acked-by: Tejun Heo Signed-off-by: Joel Fernandes (Google) Signed-off-by: Paul E. McKenney

workqueue: Fix pwq ref leak in rescuer_thread()

2019-10-04T17:23:11Z

008847f66c3 ("workqueue: allow rescuer thread to do more work.") made the rescuer worker requeue the pwq immediately if there may be more work items which need rescuing instead of waiting for the next mayday timer expiration. Unfortunately, it doesn't check whether the pwq is already on the mayday list and unconditionally gets the ref and moves it onto the list. This doesn't corrupt the list but creates an additional reference to the pwq. It got queued twice but will only be removed once. This leak later can trigger pwq refcnt warning on workqueue destruction and prevent freeing of the workqueue. Signed-off-by: Tejun Heo Cc: "Williams, Gerald S" Cc: NeilBrown Cc: stable@vger.kernel.org # v3.19+