3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Lai Jiangshan <la...@cn.fujitsu.com>
commit 6acbfb96976fc3350e30d964acb1dbbdf876d55e upstream.
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 <la...@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <pet...@infradead.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Gautham R. Shenoy <e...@linux.vnet.ibm.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Michael wang <wang...@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortma...@windriver.com>
Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
Cc: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com>
Cc: Toshi Kani <toshi.k...@hp.com>
Link: http://lkml.kernel.org/r/53758b12.8060...@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
kernel/cpu.c | 6 ++++--
kernel/sched/core.c | 1 -
2 files changed, 4 insertions(+), 3 deletions(-)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -631,10 +631,12 @@ void set_cpu_present(unsigned int cpu, b
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)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5656,7 +5656,6 @@ static int __cpuinit sched_cpu_active(st
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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