Messages in this thread Patch in this message | | | Date | Thu, 22 May 2014 05:26:02 -0700 | From | tip-bot for Lai Jiangshan <> | Subject | [tip:sched/core] sched: Fix hotplug vs. set_cpus_allowed_ptr() |
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Commit-ID: 6acbfb96976fc3350e30d964acb1dbbdf876d55e Gitweb: http://git.kernel.org/tip/6acbfb96976fc3350e30d964acb1dbbdf876d55e Author: Lai Jiangshan <laijs@cn.fujitsu.com> AuthorDate: Fri, 16 May 2014 11:50:42 +0800 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Thu, 22 May 2014 10:21:31 +0200
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 | 6 ++++-- kernel/sched/core.c | 1 - 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c index a9e710e..247979a 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -726,10 +726,12 @@ void set_cpu_present(unsigned int cpu, bool present) void set_cpu_online(unsigned int cpu, bool online) { - if (online) + if (online) { cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); - else + cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); + } else { cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); + } } void set_cpu_active(unsigned int cpu, bool active) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 44e00ab..86f3890 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5076,7 +5076,6 @@ static int sched_cpu_active(struct notifier_block *nfb, unsigned long action, void *hcpu) { switch (action & ~CPU_TASKS_FROZEN) { - case CPU_STARTING: case CPU_DOWN_FAILED: set_cpu_active((long)hcpu, true); return NOTIFY_OK;
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