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authorDavidlohr Bueso <dave@stgolabs.net>2015-01-06 11:45:06 -0800
committerIngo Molnar <mingo@kernel.org>2015-01-14 15:07:30 +0100
commit4bd19084faa61a8c68586e74f03f5776179f65c2 (patch)
treec240de51529bea98656f06fcdb9a0af383b6b29a /kernel/locking
parente42f678a0237f84f0004fbaf0fad0b844751eadd (diff)
downloadlinux-4bd19084faa61a8c68586e74f03f5776179f65c2.tar.bz2
locking/mutex: Introduce ww_mutex_set_context_slowpath()
... which is equivalent to the fastpath counter part. This mainly allows getting some WW specific code out of generic mutex paths. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1420573509-24774-4-git-send-email-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/mutex.c44
1 files changed, 26 insertions, 18 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 6db3d0dea6da..c67a60b61625 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -147,7 +147,7 @@ static __always_inline void ww_mutex_lock_acquired(struct ww_mutex *ww,
}
/*
- * after acquiring lock with fastpath or when we lost out in contested
+ * After acquiring lock with fastpath or when we lost out in contested
* slowpath, set ctx and wake up any waiters so they can recheck.
*
* This function is never called when CONFIG_DEBUG_LOCK_ALLOC is set,
@@ -191,6 +191,30 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock,
spin_unlock_mutex(&lock->base.wait_lock, flags);
}
+/*
+ * After acquiring lock in the slowpath set ctx and wake up any
+ * waiters so they can recheck.
+ *
+ * Callers must hold the mutex wait_lock.
+ */
+static __always_inline void
+ww_mutex_set_context_slowpath(struct ww_mutex *lock,
+ struct ww_acquire_ctx *ctx)
+{
+ struct mutex_waiter *cur;
+
+ ww_mutex_lock_acquired(lock, ctx);
+ lock->ctx = ctx;
+
+ /*
+ * Give any possible sleeping processes the chance to wake up,
+ * so they can recheck if they have to back off.
+ */
+ list_for_each_entry(cur, &lock->base.wait_list, list) {
+ debug_mutex_wake_waiter(&lock->base, cur);
+ wake_up_process(cur->task);
+ }
+}
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
@@ -576,23 +600,7 @@ skip_wait:
if (use_ww_ctx) {
struct ww_mutex *ww = container_of(lock, struct ww_mutex, base);
- struct mutex_waiter *cur;
-
- /*
- * This branch gets optimized out for the common case,
- * and is only important for ww_mutex_lock.
- */
- ww_mutex_lock_acquired(ww, ww_ctx);
- ww->ctx = ww_ctx;
-
- /*
- * Give any possible sleeping processes the chance to wake up,
- * so they can recheck if they have to back off.
- */
- list_for_each_entry(cur, &lock->wait_list, list) {
- debug_mutex_wake_waiter(lock, cur);
- wake_up_process(cur->task);
- }
+ ww_mutex_set_context_slowpath(ww, ww_ctx);
}
spin_unlock_mutex(&lock->wait_lock, flags);