[patch-rt 2/4] ftrace: fix erroneous histogram stop WARN_ON() messages

From: Thomas Gleixner
Date: Wed Jan 28 2009 - 16:45:55 EST


IRQs are temporarily disabled during histogram calculation in
cycles_2_ns(). This causes a nested irqs_off histogram processing
which emittes an erroneous WARN_ON() message and also confuses the
histogramm output.

Change local_irq to raw_local_irq in cycles_2_ns to prevent irqs_off
histogram processing.

Tested-by: Carsten Emde <C.Emde@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
include/asm-x86/timer.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

Index: linux-2.6.26/include/asm-x86/timer.h
===================================================================
--- linux-2.6.26.orig/include/asm-x86/timer.h
+++ linux-2.6.26/include/asm-x86/timer.h
@@ -53,9 +53,9 @@ static inline notrace unsigned long long
unsigned long long ns;
unsigned long flags;

- local_irq_save(flags);
+ raw_local_irq_save(flags);
ns = __cycles_2_ns(cyc);
- local_irq_restore(flags);
+ raw_local_irq_restore(flags);

return ns;
}

--

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