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Subject[PATCH 1/7] atomic: Export fetch_or()
Date
Export fetch_or() that's implemented and used internally by the
scheduler. We are going to use it for NO_HZ so make it generally
available.

Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
include/linux/atomic.h | 18 ++++++++++++++++++
kernel/sched/core.c | 14 --------------
2 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 00a5763..c3b99f8 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -451,6 +451,24 @@ static inline int atomic_dec_if_positive(atomic_t *v)
}
#endif

+/**
+ * fetch_or - perform *ptr |= mask and return old value of *ptr
+ * @ptr: pointer to value
+ * @mask: mask to OR on the value
+ *
+ * cmpxchg based fetch_or, macro so it works for different integer types
+ */
+#define fetch_or(ptr, mask) \
+({ typeof(*(ptr)) __old, __val = *(ptr); \
+ for (;;) { \
+ __old = cmpxchg((ptr), __val, __val | (mask)); \
+ if (__old == __val) \
+ break; \
+ __val = __old; \
+ } \
+ __old; \
+})
+
#include <asm-generic/atomic-long.h>
#ifdef CONFIG_GENERIC_ATOMIC64
#include <asm-generic/atomic64.h>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 10a8faa..63d22bd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -453,20 +453,6 @@ static inline void init_hrtick(void)
}
#endif /* CONFIG_SCHED_HRTICK */

-/*
- * cmpxchg based fetch_or, macro so it works for different integer types
- */
-#define fetch_or(ptr, val) \
-({ typeof(*(ptr)) __old, __val = *(ptr); \
- for (;;) { \
- __old = cmpxchg((ptr), __val, __val | (val)); \
- if (__old == __val) \
- break; \
- __val = __old; \
- } \
- __old; \
-})
-
#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG)
/*
* Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG,
--
2.5.3


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