Re: [block IO crash] Re: 2.6.39-rc5-git2 boot crashs

[Christoph Lameter]

On Wed, 4 May 2011, Tejun Heo wrote:

> The cmpxchg_double optimization made the fast path go quite faster
> when CPU supports it but it may as well slow things down considerably
> if CPU doesn't, due to extra irq on/off's.  Anyways, here's hoping
> that the slow down is acceptable compared to the base code without
> cmpxchg_double and the ugliness can be removed.

I think we are all in agreement. First path to fix the percpu macros:


Subject: percpu: Fix irqsafe_cpu_cmpxchg_double

The function in the macro was not updated when the function was given a bool return value.

Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>

---
 include/linux/percpu.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/include/linux/percpu.h
===================================================================
--- linux-2.6.orig/include/linux/percpu.h	2011-05-04 09:33:08.000000000 -0500
+++ linux-2.6/include/linux/percpu.h	2011-05-04 09:33:39.000000000 -0500
@@ -948,7 +948,7 @@ do {									\
 	irqsafe_generic_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)
 # endif
 # define irqsafe_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)	\
-	__pcpu_double_call_return_int(irqsafe_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
+	__pcpu_double_call_return_bool(irqsafe_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
 #endif

 #endif /* __LINUX_PERCPU_H */
--
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