Searched hist:"9 ab03be4" (Results 1 – 1 of 1) sorted by relevance
| /openbmc/linux/kernel/ |
| H A D | workqueue.c | 9ab03be4 Thu Jan 12 10:14:30 CST 2023 Valentin Schneider <vschneid@redhat.com> workqueue: Don't hold any lock while rcuwait'ing for !POOL_MANAGER_ACTIVE
put_unbound_pool() currently passes wq_manager_inactive() as exit condition
to rcuwait_wait_event(), which grabs pool->lock to check for
pool->flags & POOL_MANAGER_ACTIVE
A later patch will require destroy_worker() to be invoked with
wq_pool_attach_mutex held, which needs to be acquired before
pool->lock. A mutex cannot be acquired within rcuwait_wait_event(), as
it could clobber the task state set by rcuwait_wait_event()
Instead, restructure the waiting logic to acquire any necessary lock
outside of rcuwait_wait_event().
Since further work cannot be inserted into unbound pwqs that have reached
->refcnt==0, this is bound to make forward progress as eventually the
worklist will be drained and need_more_worker(pool) will remain false,
preventing any worker from stealing the manager position from us.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|