[PATCH] powerpc: check_and_cede_processor never cedes
anton at samba.org
Thu Jun 28 08:45:09 EST 2012
Commit f948501b36c6 ("Make hard_irq_disable() actually hard-disable
interrupts") caused check_and_cede_processor to stop working.
->irq_happened will never be zero right after a hard_irq_disable
so the compiler removes the call to cede_processor completely.
The bug was introduced back in the lazy interrupt handling rework
of 3.4 but was hidden until recently because hard_irq_disable did
This issue will eventually appear in 3.4 stable since the
hard_irq_disable fix is marked stable, so mark this one for stable
Signed-off-by: Anton Blanchard <anton at samba.org>
Cc: stable at vger.kernel.org
--- linux-build.orig/arch/powerpc/platforms/pseries/processor_idle.c 2012-06-27 21:20:45.403761715 +1000
+++ linux-build/arch/powerpc/platforms/pseries/processor_idle.c 2012-06-27 21:57:14.796788823 +1000
@@ -106,7 +106,7 @@ static void check_and_cede_processor(voi
* we first hard disable then check.
- if (get_paca()->irq_happened == 0)
+ if (get_paca()->irq_happened == PACA_IRQ_HARD_DIS)
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