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| author | Peter Zijlstra <peterz@infradead.org> | 2016-04-04 11:57:12 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-14 12:54:27 +0300 |
| commit | 1f03e8d2919270bd6ef64f39a45ce8df8a9f012a (patch) | |
| tree | 0cdd5de370212a021d0a1a3439bbc4b0a77fea8b /kernel/smp.c | |
| parent | 245050c287a9176cee9f98109df101909c1eeef4 (diff) | |
| download | linux-1f03e8d2919270bd6ef64f39a45ce8df8a9f012a.tar.xz | |
locking/barriers: Replace smp_cond_acquire() with smp_cond_load_acquire()
This new form allows using hardware assisted waiting.
Some hardware (ARM64 and x86) allow monitoring an address for changes,
so by providing a pointer we can use this to replace the cpu_relax()
with hardware optimized methods in the future.
Requested-by: Will Deacon <will.deacon@arm.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/smp.c')
| -rw-r--r-- | kernel/smp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/smp.c b/kernel/smp.c index 74165443c240..36552beed397 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -107,7 +107,7 @@ void __init call_function_init(void) */ static __always_inline void csd_lock_wait(struct call_single_data *csd) { - smp_cond_acquire(!(csd->flags & CSD_FLAG_LOCK)); + smp_cond_load_acquire(&csd->flags, !(VAL & CSD_FLAG_LOCK)); } static __always_inline void csd_lock(struct call_single_data *csd) |