From: Lai Jiangshan <[email protected]> To simplify locking, the previous patches expanded wq->mutex to protect all fields of each workqueue instance including the pwqs list leaving pwq_lock without any user. Remove the unused pwq_lock.
tj: Rebased on top of the current dev branch. Updated description. Signed-off-by: Lai Jiangshan <[email protected]> Signed-off-by: Tejun Heo <[email protected]> --- kernel/workqueue.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index af6087a..04a8b98 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -125,12 +125,9 @@ enum { * * PR: wq_pool_mutex protected for writes. Sched-RCU protected for reads. * - * PW: pwq_lock protected. - * * WQ: wq->mutex protected. * - * WR: wq->mutex and pwq_lock protected for writes. Sched-RCU protected - * for reads. + * WR: wq->mutex protected for writes. Sched-RCU protected for reads. * * MD: wq_mayday_lock protected. */ @@ -257,7 +254,6 @@ struct workqueue_struct { static struct kmem_cache *pwq_cache; static DEFINE_MUTEX(wq_pool_mutex); /* protects pools and workqueues list */ -static DEFINE_SPINLOCK(pwq_lock); /* protects pool_workqueues */ static DEFINE_SPINLOCK(wq_mayday_lock); /* protects wq->maydays list */ static LIST_HEAD(workqueues); /* PL: list of all workqueues */ @@ -300,8 +296,7 @@ static void copy_workqueue_attrs(struct workqueue_attrs *to, #define assert_rcu_or_wq_mutex(wq) \ rcu_lockdep_assert(rcu_read_lock_sched_held() || \ - lockdep_is_held(&wq->mutex) || \ - lockdep_is_held(&pwq_lock), \ + lockdep_is_held(&wq->mutex), \ "sched RCU or wq->mutex should be held") #ifdef CONFIG_LOCKDEP @@ -3549,9 +3544,7 @@ static void pwq_unbound_release_workfn(struct work_struct *work) * and consistent with the linking path. */ mutex_lock(&wq->mutex); - spin_lock_irq(&pwq_lock); list_del_rcu(&pwq->pwqs_node); - spin_unlock_irq(&pwq_lock); mutex_unlock(&wq->mutex); put_unbound_pool(pool); @@ -3635,9 +3628,7 @@ static void init_and_link_pwq(struct pool_workqueue *pwq, pwq_adjust_max_active(pwq); /* link in @pwq */ - spin_lock_irq(&pwq_lock); list_add_rcu(&pwq->pwqs_node, &wq->pwqs); - spin_unlock_irq(&pwq_lock); mutex_unlock(&wq->mutex); } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
