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authorTejun Heo <tj@kernel.org>2011-01-20 12:07:13 +0100
committerIngo Molnar <mingo@elte.hu>2011-01-20 13:32:34 +0100
commitbd924e8cbd4b73ffb7d707a774c04f7e2cae88ed (patch)
tree338d08c708b195acb9c8d6e0bab2e6ea720051a3 /kernel
parent2ce802f62ba32a7d95748ac92bf351f76affb6ff (diff)
downloadlinux-linaro-precise-bd924e8cbd4b73ffb7d707a774c04f7e2cae88ed.tar.gz
smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c
percpu may end up calling vfree() during early boot which in turn may call on_each_cpu() for TLB flushes. The function of on_each_cpu() can be done safely while IRQ is disabled during early boot but it assumed that the function is always called with local IRQ enabled which ended up enabling local IRQ prematurely during boot and triggering a couple of warnings. This patch updates on_each_cpu() and smp_call_function_many() such on_each_cpu() can be used safely while early_boot_irqs_disabled is set. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110120110713.GC6036@htj.dyndns.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Reported-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/smp.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/kernel/smp.c b/kernel/smp.c
index 4ec30e06998..4b83cd6815e 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -430,7 +430,7 @@ void smp_call_function_many(const struct cpumask *mask,
* can't happen.
*/
WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
- && !oops_in_progress);
+ && !oops_in_progress && !early_boot_irqs_disabled);
/* So, what's a CPU they want? Ignoring this one. */
cpu = cpumask_first_and(mask, cpu_online_mask);
@@ -533,17 +533,20 @@ void ipi_call_unlock_irq(void)
#endif /* USE_GENERIC_SMP_HELPERS */
/*
- * Call a function on all processors
+ * Call a function on all processors. May be used during early boot while
+ * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead
+ * of local_irq_disable/enable().
*/
int on_each_cpu(void (*func) (void *info), void *info, int wait)
{
+ unsigned long flags;
int ret = 0;
preempt_disable();
ret = smp_call_function(func, info, wait);
- local_irq_disable();
+ local_irq_save(flags);
func(info);
- local_irq_enable();
+ local_irq_restore(flags);
preempt_enable();
return ret;
}