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| author | Nicolai Hähnle <Nicolai.Haehnle@amd.com> | 2016-12-21 19:46:31 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-01-14 11:14:39 +0100 |
| commit | 3822da3ed0676e01f83fe0518c333c8e9ba249bf (patch) | |
| tree | b1fef389fa35df9745b0aa9ec8f76a0788622934 /kernel/locking | |
| parent | e274795ea7b7caa0fd74ef651594382a69e2a951 (diff) | |
| download | lwn-3822da3ed0676e01f83fe0518c333c8e9ba249bf.tar.gz lwn-3822da3ed0676e01f83fe0518c333c8e9ba249bf.zip | |
locking/ww_mutex: Extract stamp comparison to __ww_mutex_stamp_after()
The function will be re-used in subsequent patches.
Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <dev@mblankhorst.nl>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1482346000-9927-4-git-send-email-nhaehnle@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/mutex.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 24284497c425..9ad03b9a5f7f 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -281,6 +281,13 @@ static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww, ww_ctx->acquired++; } +static inline bool __sched +__ww_ctx_stamp_after(struct ww_acquire_ctx *a, struct ww_acquire_ctx *b) +{ + return a->stamp - b->stamp <= LONG_MAX && + (a->stamp != b->stamp || a > b); +} + /* * After acquiring lock with fastpath or when we lost out in contested * slowpath, set ctx and wake up any waiters so they can recheck. @@ -597,8 +604,7 @@ __ww_mutex_lock_check_stamp(struct mutex *lock, struct ww_acquire_ctx *ctx) if (!hold_ctx) return 0; - if (ctx->stamp - hold_ctx->stamp <= LONG_MAX && - (ctx->stamp != hold_ctx->stamp || ctx > hold_ctx)) { + if (__ww_ctx_stamp_after(ctx, hold_ctx)) { #ifdef CONFIG_DEBUG_MUTEXES DEBUG_LOCKS_WARN_ON(ctx->contending_lock); ctx->contending_lock = ww; |