From: Bart Van Assche <bvanassche@acm.org>
To: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org,
Johannes Berg <johannes.berg@intel.com>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
tytso@mit.edu, bvanassche@acm.org
Subject: [PATCH 1/3] kernel/workqueue: Remove lockdep annotation from __flush_work()
Date: Thu, 25 Oct 2018 08:05:38 -0700 [thread overview]
Message-ID: <20181025150540.259281-2-bvanassche@acm.org> (raw)
In-Reply-To: <20181025150540.259281-1-bvanassche@acm.org>
As documented in a comment in start_flush_work(), calling flush_work()
from a multi-threaded workqueue is safe if that workqueue is not
equipped with a rescuer. Avoid that flush_work() calls from inside a
work item executing on such a queue trigger a lockdep complaint. Remove
the lockdep annotation from __flush_work() because start_flush_work()
already has such an annotation.
Fixes: 87915adc3f0a ("workqueue: re-add lockdep dependencies for flushing")
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
kernel/workqueue.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 0280deac392e..6755ef21a679 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2908,11 +2908,6 @@ static bool __flush_work(struct work_struct *work, bool from_cancel)
if (WARN_ON(!wq_online))
return false;
- if (!from_cancel) {
- lock_map_acquire(&work->lockdep_map);
- lock_map_release(&work->lockdep_map);
- }
-
if (start_flush_work(work, &barr, from_cancel)) {
wait_for_completion(&barr.done);
destroy_work_on_stack(&barr.work);
--
2.19.1.568.g152ad8e336-goog
next prev parent reply other threads:[~2018-10-25 15:07 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-25 15:05 [PATCH 0/3] Suppress false positives triggered by workqueue lockdep annotations Bart Van Assche
2018-10-25 15:05 ` Bart Van Assche [this message]
2018-10-25 15:31 ` [PATCH 1/3] kernel/workqueue: Remove lockdep annotation from __flush_work() Johannes Berg
2018-10-25 15:57 ` Johannes Berg
2018-10-25 16:01 ` Bart Van Assche
2018-10-25 15:05 ` [PATCH 2/3] kernel/workqueue: Surround work execution with shared lock annotations Bart Van Assche
2018-10-25 16:53 ` Johannes Berg
2018-10-25 17:22 ` Bart Van Assche
2018-10-25 19:17 ` Johannes Berg
2018-10-25 15:05 ` [PATCH 3/3] kernel/workqueue: Suppress a false positive lockdep complaint Bart Van Assche
2018-10-25 15:34 ` Johannes Berg
2018-10-25 15:55 ` Bart Van Assche
2018-10-25 19:59 ` Johannes Berg
2018-10-25 20:21 ` Theodore Y. Ts'o
2018-10-25 20:26 ` Johannes Berg
2018-10-25 15:36 ` Tejun Heo
2018-10-25 15:37 ` Tejun Heo
2018-10-25 20:13 ` Johannes Berg
2018-10-25 15:40 ` Theodore Y. Ts'o
2018-10-25 17:02 ` Johannes Berg
2018-10-25 17:11 ` Bart Van Assche
2018-10-25 19:51 ` Johannes Berg
2018-10-25 20:39 ` Bart Van Assche
2018-10-25 20:47 ` Johannes Berg
2018-10-25 15:27 ` [PATCH 0/3] Suppress false positives triggered by workqueue lockdep annotations Johannes Berg
2018-10-25 15:47 ` Bart Van Assche
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