search for: wait_lock

...wsem_downgrade_wake(struct rw_semaphore *sem) return sem; } +/* + * check to see if the rwsem we''re holding has anybody waiting to acquire it. + */ +int rwsem_is_contended(struct rw_semaphore *sem) +{ + int ret = 0; + unsigned long flags; + + if (!raw_spin_trylock_irqsave(&sem->wait_lock, flags)) + return 1; + if (!list_empty(&sem->wait_list)) + ret = 1; + raw_spin_unlock_irqrestore(&sem->wait_lock, flags); + return ret; +} + +EXPORT_SYMBOL(rwsem_is_contended); EXPORT_SYMBOL(rwsem_down_read_failed); EXPORT_SYMBOL(rwsem_down_write_failed); EXPORT_SYMBOL(rwsem_wake...

...owlatency(); + cpu_relax(); } /* When no more readers, set the locked flag */ @@ -141,7 +141,7 @@ void queued_write_lock_slowpath(struct qrwlock *lock) _QW_LOCKED) == _QW_WAITING)) break; - cpu_relax_lowlatency(); + cpu_relax(); } unlock: arch_spin_unlock(&lock->wait_lock); diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c index 2337b4b..2fa2e2e6 100644 --- a/kernel/locking/rwsem-xadd.c +++ b/kernel/locking/rwsem-xadd.c @@ -368,7 +368,7 @@ static noinline bool rwsem_spin_on_owner(struct rw_semaphore *sem) return false; } - cpu_relax_lo...

This series introduces a generic readahead interface for btrfs trees. The intention is to use it to speed up scrub in a first run, but balance is another hot candidate. In general, every tree walk could be accompanied by a readahead. Deletion of large files comes to mind, where the fetching of the csums takes most of the time. Also the initial build-ups of free-space-caches and

This series introduces a generic readahead interface for btrfs trees. The intention is to use it to speed up scrub in a first run, but balance is another hot candidate. In general, every tree walk could be accompanied by a readahead. Deletion of large files comes to mind, where the fetching of the csums takes most of the time. Also the initial build-ups of free-space-caches and

Peter, here is v2 with some improved patch descriptions and some fixes. The previous version has survived one day of linux-next and I only changed small parts. So unless there is some other issue, feel free to pull (or to apply the patches) to tip/locking. The following changes since commit 07d9a380680d1c0eb51ef87ff2eab5c994949e69: Linux 4.9-rc2 (2016-10-23 17:10:14 -0700) are available in

Peter, here is v2 with some improved patch descriptions and some fixes. The previous version has survived one day of linux-next and I only changed small parts. So unless there is some other issue, feel free to pull (or to apply the patches) to tip/locking. The following changes since commit 07d9a380680d1c0eb51ef87ff2eab5c994949e69: Linux 4.9-rc2 (2016-10-23 17:10:14 -0700) are available in