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yaml
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r: 221714
b: refs/heads/master
c: 3f9d35b
h: refs/heads/master
v: v3
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Eric Dumazet authored and Linus Torvalds committed Nov 12, 2010
1 parent 954b4f0 commit 534b672
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Showing 2 changed files with 38 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
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---
refs/heads/master: 8705a1baf78287eceeb00bc29401d0ae6a03f213
refs/heads/master: 3f9d35b9514da6757ca98831372518f9eeb71b33
37 changes: 37 additions & 0 deletions trunk/include/linux/atomic.h
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#ifndef _LINUX_ATOMIC_H
#define _LINUX_ATOMIC_H
#include <asm/atomic.h>

/**
* atomic_inc_not_zero_hint - increment if not null
* @v: pointer of type atomic_t
* @hint: probable value of the atomic before the increment
*
* This version of atomic_inc_not_zero() gives a hint of probable
* value of the atomic. This helps processor to not read the memory
* before doing the atomic read/modify/write cycle, lowering
* number of bus transactions on some arches.
*
* Returns: 0 if increment was not done, 1 otherwise.
*/
#ifndef atomic_inc_not_zero_hint
static inline int atomic_inc_not_zero_hint(atomic_t *v, int hint)
{
int val, c = hint;

/* sanity test, should be removed by compiler if hint is a constant */
if (!hint)
return atomic_inc_not_zero(v);

do {
val = atomic_cmpxchg(v, c, c + 1);
if (val == c)
return 1;
c = val;
} while (c);

return 0;
}
#endif

#endif /* _LINUX_ATOMIC_H */

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