Re: [PATCH v3 -rcu] workqueue: Convert for_each_wq to use built-in list check
From: Paul E. McKenney <hidden>
Date: 2019-08-16 16:46:04
Also in:
lkml, rcu
On Thu, Aug 15, 2019 at 10:18:42AM -0400, Joel Fernandes (Google) wrote:
list_for_each_entry_rcu now has support to check for RCU reader sections as well as lock. Just use the support in it, instead of explicitly checking in the caller. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Joel Fernandes (Google) <redacted>
Pulled into -rcu for testing and further review, thank you! Thanx, Paul
quoted hunk ↗ jump to hunk
--- v1->v3: Changed lock_is_held() to lockdep_is_held() kernel/workqueue.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 601d61150b65..e882477ebf6e 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c@@ -364,11 +364,6 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); !lockdep_is_held(&wq_pool_mutex), \ "RCU or wq_pool_mutex should be held") -#define assert_rcu_or_wq_mutex(wq) \ - RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ - !lockdep_is_held(&wq->mutex), \ - "RCU or wq->mutex should be held") - #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \ RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \ !lockdep_is_held(&wq->mutex) && \@@ -425,9 +420,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); * ignored. */ #define for_each_pwq(pwq, wq) \ - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ - else + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \ + lockdep_is_held(&(wq->mutex))) #ifdef CONFIG_DEBUG_OBJECTS_WORK-- 2.23.0.rc1.153.gdeed80330f-goog