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| author | Peter Zijlstra <peterz@infradead.org> | 2016-07-14 14:26:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-08-10 14:16:02 +0200 |
| commit | 64a5e3cb308028dba0676daae0a7821d770036fa (patch) | |
| tree | c50fac7c350895f3ec81662f53cbee6c4e64d9e2 /kernel/locking/qspinlock_paravirt.h | |
| parent | locking/pvqspinlock: Fix a bug in qstat_read() (diff) | |
| download | linux-64a5e3cb308028dba0676daae0a7821d770036fa.tar.xz linux-64a5e3cb308028dba0676daae0a7821d770036fa.zip | |
locking/qspinlock: Improve readability
Restructure pv_queued_spin_steal_lock() as I found it hard to read.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <waiman.long@hpe.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking/qspinlock_paravirt.h')
| -rw-r--r-- | kernel/locking/qspinlock_paravirt.h | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index 8a99abf58080..429c3dc2a5f3 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -70,11 +70,14 @@ struct pv_node { static inline bool pv_queued_spin_steal_lock(struct qspinlock *lock) { struct __qspinlock *l = (void *)lock; - int ret = !(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && - (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0); - qstat_inc(qstat_pv_lock_stealing, ret); - return ret; + if (!(atomic_read(&lock->val) & _Q_LOCKED_PENDING_MASK) && + (cmpxchg(&l->locked, 0, _Q_LOCKED_VAL) == 0)) { + qstat_inc(qstat_pv_lock_stealing, true); + return true; + } + + return false; } /* @@ -257,7 +260,6 @@ static struct pv_node *pv_unhash(struct qspinlock *lock) static inline bool pv_wait_early(struct pv_node *prev, int loop) { - if ((loop & PV_PREV_CHECK_MASK) != 0) return false; |