sched: Fix hotplug vs. set_cpus_allowed_ptr()
authorLai Jiangshan <laijs@cn.fujitsu.com>
Fri, 16 May 2014 03:50:42 +0000 (11:50 +0800)
committerIngo Molnar <mingo@kernel.org>
Thu, 22 May 2014 08:21:31 +0000 (10:21 +0200)
commit6acbfb96976fc3350e30d964acb1dbbdf876d55e
tree545a0c3d49d4603b568bf33c295f5c5504c0d334
parent4dac0b638310d2e92f6e19958b73d4c97c9734bb
sched: Fix hotplug vs. set_cpus_allowed_ptr()

Lai found that:

  WARNING: CPU: 1 PID: 13 at arch/x86/kernel/smp.c:124 native_smp_send_reschedule+0x2d/0x4b()
  ...
  migration_cpu_stop+0x1d/0x22

was caused by set_cpus_allowed_ptr() assuming that cpu_active_mask is
always a sub-set of cpu_online_mask.

This isn't true since 5fbd036b552f ("sched: Cleanup cpu_active madness").

So set active and online at the same time to avoid this particular
problem.

Fixes: 5fbd036b552f ("sched: Cleanup cpu_active madness")
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael wang <wangyun@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/53758B12.8060609@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/cpu.c
kernel/sched/core.c