asm-generic: use raw_local_irq_save/restore instead local_irq_save/restore
authorMichal Simek <monstr@monstr.eu>
Tue, 10 Aug 2010 00:18:24 +0000 (17:18 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 10 Aug 2010 03:44:54 +0000 (20:44 -0700)
The start/stop_critical_timing functions for preemptirqsoff, preemptoff
and irqsoff tracers contain atomic_inc() and atomic_dec() operations.

Atomic operations use local_irq_save/restore macros to ensure atomic
access but they are traced by the same function which is causing recursion
problem.

The reason is when these tracers are turn ON then the
local_irq_save/restore macros are changed in include/linux/irqflags.h to
call trace_hardirqs_on/off which call start/stop_critical_timing.

Microblaze was affected because it uses generic atomic implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-generic/atomic.h

index 058129e9b04c75f8cf7d5c24a9f1fa5b0cbe7bed..e53347fbf1da6bdc85aa45ef66ed1c47bdb65a08 100644 (file)
@@ -57,11 +57,11 @@ static inline int atomic_add_return(int i, atomic_t *v)
        unsigned long flags;
        int temp;
 
-       local_irq_save(flags);
+       raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
        temp = v->counter;
        temp += i;
        v->counter = temp;
-       local_irq_restore(flags);
+       raw_local_irq_restore(flags);
 
        return temp;
 }
@@ -78,11 +78,11 @@ static inline int atomic_sub_return(int i, atomic_t *v)
        unsigned long flags;
        int temp;
 
-       local_irq_save(flags);
+       raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
        temp = v->counter;
        temp -= i;
        v->counter = temp;
-       local_irq_restore(flags);
+       raw_local_irq_restore(flags);
 
        return temp;
 }
@@ -135,9 +135,9 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
        unsigned long flags;
 
        mask = ~mask;
-       local_irq_save(flags);
+       raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
        *addr &= mask;
-       local_irq_restore(flags);
+       raw_local_irq_restore(flags);
 }
 
 #define atomic_xchg(ptr, v)            (xchg(&(ptr)->counter, (v)))