Tejun Heo feb245e304 sched/core: Allow kthreads to fall back to online && !active cpus ...

During CPU hotplug, CPU_ONLINE callbacks are run while the CPU is
online but not active.  A CPU_ONLINE callback may create or bind a
kthread so that its cpus_allowed mask only allows the CPU which is
being brought online.  The kthread may start executing before the CPU
is made active and can end up in select_fallback_rq().

In such cases, the expected behavior is selecting the CPU which is
coming online; however, because select_fallback_rq() only chooses from
active CPUs, it determines that the task doesn't have any viable CPU
in its allowed mask and ends up overriding it to cpu_possible_mask.

CPU_ONLINE callbacks should be able to put kthreads on the CPU which
is coming online.  Update select_fallback_rq() so that it follows
cpu_online() rather than cpu_active() for kthreads.

Reported-by: Gautham R Shenoy <[email protected]>
Tested-by: Gautham R. Shenoy <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Abdul Haleem <[email protected]>
Cc: Aneesh Kumar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

2016-06-24 08:26:53 +02:00

..

auto_group.c

sched/core: Move the sched_to_prio[] arrays out of line

2015-12-04 10:34:46 +01:00

auto_group.h

sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE()

2015-05-08 12:11:32 +02:00

clock.c

sched/clock: Make local_clock()/cpu_clock() inline

2016-04-13 12:25:22 +02:00

completion.c

sched/completion: Serialize completion_done() with complete()

2015-02-18 14:27:40 +01:00

core.c

sched/core: Allow kthreads to fall back to online && !active cpus

2016-06-24 08:26:53 +02:00

cpuacct.c

sched/cpuacct: Check for NULL when using task_pt_regs()

2016-04-13 13:22:37 +02:00

cpuacct.h

sched/cpuacct: Simplify the cpuacct code

2016-03-21 11:00:28 +01:00

cpudeadline.c

sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed

2016-05-12 09:55:35 +02:00

cpudeadline.h

sched/deadline: Unify dl_time_before() usage

2015-09-23 09:51:25 +02:00

cpufreq_schedutil.c

cpufreq: schedutil: Improve prints messages with pr_fmt

2016-05-19 01:02:52 +02:00

cpufreq.c

cpufreq: sched: Helpers to add and remove update_util hooks

2016-04-02 01:08:43 +02:00

cpupri.c

sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed

2016-05-12 09:55:35 +02:00

cpupri.h

sched/cpupri: Remove unnecessary definitions in cpupri.h

2014-11-16 10:58:59 +01:00

cputime.c

sched/cputime: Fix steal_account_process_tick() to always return jiffies

2016-03-08 12:24:56 +01:00

deadline.c

sched/core: Provide a tsk_nr_cpus_allowed() helper

2016-05-12 09:55:36 +02:00

debug.c

sched/debug: Fix /proc/sched_debug regression

2016-06-08 14:31:58 +02:00

fair.c

sched/fair: Do not announce throttled next buddy in dequeue_task_fair()

2016-06-24 08:26:45 +02:00

features.h

sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define

2015-09-13 09:52:55 +02:00

idle_task.c

locking/lockdep, sched/core: Implement a better lock pinning scheme

2016-05-05 09:23:59 +02:00

idle.c

cpuidle: Do not access cpuidle_devices when !CONFIG_CPU_IDLE

2016-06-02 23:05:27 +02:00

loadavg.c

sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems

2016-05-12 09:55:34 +02:00

Makefile

cpufreq: schedutil: New governor based on scheduler utilization data

2016-04-02 01:09:12 +02:00

rt.c

sched/core: Provide a tsk_nr_cpus_allowed() helper

2016-05-12 09:55:36 +02:00

sched.h

sched/fair: Initialize throttle_count for new task-groups lazily

2016-06-24 08:26:44 +02:00

stats.c

sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks

2015-02-13 21:21:37 -08:00

stats.h

sched/debug: Fix /proc/sched_debug regression

2016-06-08 14:31:58 +02:00

stop_task.c

locking/lockdep, sched/core: Implement a better lock pinning scheme

2016-05-05 09:23:59 +02:00

swait.c

wait.[ch]: Introduce the simple waitqueue (swait) implementation

2016-02-25 11:27:16 +01:00

wait.c

sched/wait: Fix the signal handling fix

2015-12-13 14:30:59 -08:00