From: Byungchul Park <byungchul.park@lge.com> To: peterz@infradead.org, mingo@kernel.org Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, tj@kernel.org, johannes.berg@intel.com, oleg@redhat.com, amir73il@gmail.com, david@fromorbit.com, darrick.wong@oracle.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, hch@infradead.org, idryomov@gmail.com, kernel-team@lge.com Subject: [RESEND PATCH 2/3] lockdep: Remove unnecessary acquisitions wrt workqueue flush Date: Wed, 18 Oct 2017 18:38:51 +0900 [thread overview] Message-ID: <1508319532-24655-3-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1508319532-24655-1-git-send-email-byungchul.park@lge.com> The workqueue added manual acquisitions to catch deadlock cases. Now crossrelease was introduced, some of those are redundant, since wait_for_completion() already includes the acquisition for itself. Removed it. Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- include/linux/workqueue.h | 4 ++-- kernel/workqueue.c | 20 ++++---------------- 2 files changed, 6 insertions(+), 18 deletions(-) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index db6dc9d..1bef13e 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -218,7 +218,7 @@ static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { } \ __init_work((_work), _onstack); \ (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ - lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \ + lockdep_init_map(&(_work)->lockdep_map, "(complete)"#_work, &__key, 0); \ INIT_LIST_HEAD(&(_work)->entry); \ (_work)->func = (_func); \ } while (0) @@ -398,7 +398,7 @@ enum { static struct lock_class_key __key; \ const char *__lock_name; \ \ - __lock_name = #fmt#args; \ + __lock_name = "(complete)"#fmt#args; \ \ __alloc_workqueue_key((fmt), (flags), (max_active), \ &__key, __lock_name, ##args); \ diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ab3c0dc..72f68b1 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2497,15 +2497,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_with_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2611,16 +2604,14 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), }; int next_color; + init_completion_with_map(&this_flusher.done, &wq->lockdep_map); + if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2883,9 +2874,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work); -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Byungchul Park <byungchul.park@lge.com> To: peterz@infradead.org, mingo@kernel.org Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, tj@kernel.org, johannes.berg@intel.com, oleg@redhat.com, amir73il@gmail.com, david@fromorbit.com, darrick.wong@oracle.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, hch@infradead.org, idryomov@gmail.com, kernel-team@lge.com Subject: [RESEND PATCH 2/3] lockdep: Remove unnecessary acquisitions wrt workqueue flush Date: Wed, 18 Oct 2017 18:38:51 +0900 [thread overview] Message-ID: <1508319532-24655-3-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1508319532-24655-1-git-send-email-byungchul.park@lge.com> The workqueue added manual acquisitions to catch deadlock cases. Now crossrelease was introduced, some of those are redundant, since wait_for_completion() already includes the acquisition for itself. Removed it. Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- include/linux/workqueue.h | 4 ++-- kernel/workqueue.c | 20 ++++---------------- 2 files changed, 6 insertions(+), 18 deletions(-) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index db6dc9d..1bef13e 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -218,7 +218,7 @@ static inline void destroy_delayed_work_on_stack(struct delayed_work *work) { } \ __init_work((_work), _onstack); \ (_work)->data = (atomic_long_t) WORK_DATA_INIT(); \ - lockdep_init_map(&(_work)->lockdep_map, #_work, &__key, 0); \ + lockdep_init_map(&(_work)->lockdep_map, "(complete)"#_work, &__key, 0); \ INIT_LIST_HEAD(&(_work)->entry); \ (_work)->func = (_func); \ } while (0) @@ -398,7 +398,7 @@ enum { static struct lock_class_key __key; \ const char *__lock_name; \ \ - __lock_name = #fmt#args; \ + __lock_name = "(complete)"#fmt#args; \ \ __alloc_workqueue_key((fmt), (flags), (max_active), \ &__key, __lock_name, ##args); \ diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ab3c0dc..72f68b1 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2497,15 +2497,8 @@ static void insert_wq_barrier(struct pool_workqueue *pwq, INIT_WORK_ONSTACK(&barr->work, wq_barrier_func); __set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(&barr->work)); - /* - * Explicitly init the crosslock for wq_barrier::done, make its lock - * key a subkey of the corresponding work. As a result we won't - * build a dependency between wq_barrier::done and unrelated work. - */ - lockdep_init_map_crosslock((struct lockdep_map *)&barr->done.map, - "(complete)wq_barr::done", - target->lockdep_map.key, 1); - __init_completion(&barr->done); + init_completion_with_map(&barr->done, &target->lockdep_map); + barr->task = current; /* @@ -2611,16 +2604,14 @@ void flush_workqueue(struct workqueue_struct *wq) struct wq_flusher this_flusher = { .list = LIST_HEAD_INIT(this_flusher.list), .flush_color = -1, - .done = COMPLETION_INITIALIZER_ONSTACK(this_flusher.done), }; int next_color; + init_completion_with_map(&this_flusher.done, &wq->lockdep_map); + if (WARN_ON(!wq_online)) return; - lock_map_acquire(&wq->lockdep_map); - lock_map_release(&wq->lockdep_map); - mutex_lock(&wq->mutex); /* @@ -2883,9 +2874,6 @@ bool flush_work(struct work_struct *work) if (WARN_ON(!wq_online)) return false; - lock_map_acquire(&work->lockdep_map); - lock_map_release(&work->lockdep_map); - if (start_flush_work(work, &barr)) { wait_for_completion(&barr.done); destroy_work_on_stack(&barr.work); -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-10-18 9:38 UTC|newest] Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-10-18 9:38 Fix false positive by LOCKDEP_CROSSRELEASE Byungchul Park 2017-10-18 9:38 ` Byungchul Park 2017-10-18 9:38 ` [RESEND PATCH 1/3] completion: Add support for initializing completion with lockdep_map Byungchul Park 2017-10-18 9:38 ` Byungchul Park 2017-10-19 23:24 ` Bart Van Assche 2017-10-19 23:24 ` Bart Van Assche 2017-10-20 6:14 ` Byungchul Park 2017-10-20 6:14 ` Byungchul Park 2017-10-20 6:34 ` Thomas Gleixner 2017-10-20 6:34 ` Thomas Gleixner 2017-10-20 19:58 ` Bart Van Assche 2017-10-20 19:58 ` Bart Van Assche 2017-10-20 19:58 ` Bart Van Assche 2017-10-21 2:23 ` Byungchul Park 2017-10-21 2:23 ` Byungchul Park 2017-10-22 14:34 ` Bart Van Assche 2017-10-22 14:34 ` Bart Van Assche 2017-10-23 2:08 ` Byungchul Park 2017-10-23 2:08 ` Byungchul Park 2017-10-25 7:07 ` Bart Van Assche 2017-10-25 7:07 ` Bart Van Assche 2017-10-25 11:49 ` Byungchul Park 2017-10-25 11:49 ` Byungchul Park 2017-10-18 9:38 ` Byungchul Park [this message] 2017-10-18 9:38 ` [RESEND PATCH 2/3] lockdep: Remove unnecessary acquisitions wrt workqueue flush Byungchul Park 2017-10-18 9:38 ` [RESEND PATCH 3/3] lockdep: Assign a lock_class per gendisk used for wait_for_completion() Byungchul Park 2017-10-18 9:38 ` Byungchul Park 2017-10-18 9:59 ` Ingo Molnar 2017-10-18 9:59 ` Ingo Molnar 2017-10-19 1:57 ` Byungchul Park 2017-10-19 1:57 ` Byungchul Park 2017-10-18 14:29 ` Fix false positive by LOCKDEP_CROSSRELEASE Bart Van Assche 2017-10-18 14:29 ` Bart Van Assche 2017-10-19 1:57 ` Byungchul Park 2017-10-19 1:57 ` Byungchul Park 2017-10-19 14:52 ` Bart Van Assche 2017-10-19 14:52 ` Bart Van Assche 2017-10-19 14:52 ` Bart Van Assche
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