From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Subject: [PATCH 3/9 V3] workqueue: add POOL_MANAGING_WORKERS
Date: Thu, 30 Aug 2012 00:51:54 +0800 [thread overview]
Message-ID: <1346259120-6216-4-git-send-email-laijs@cn.fujitsu.com> (raw)
In-Reply-To: <1346259120-6216-1-git-send-email-laijs@cn.fujitsu.com>
When hotplug happens, the plug code will also grab the manager_mutex,
it will break too_many_workers()'s assumption, and make too_many_workers()
ugly(kick the timer wrongly, no found bug).
To avoid assumption-coruption, we add the original POOL_MANAGING_WORKERS back.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
---
kernel/workqueue.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1363b39..0673598 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -66,6 +66,7 @@ enum {
/* pool flags */
POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */
+ POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */
/* worker flags */
WORKER_STARTED = 1 << 0, /* started */
@@ -652,7 +653,7 @@ static bool need_to_manage_workers(struct worker_pool *pool)
/* Do we have too many workers and should some go away? */
static bool too_many_workers(struct worker_pool *pool)
{
- bool managing = mutex_is_locked(&pool->manager_mutex);
+ bool managing = pool->flags & POOL_MANAGING_WORKERS;
int nr_idle = pool->nr_idle + managing; /* manager is considered idle */
int nr_busy = pool->nr_workers - nr_idle;
@@ -1836,6 +1837,7 @@ static bool manage_workers(struct worker *worker)
return ret;
pool->flags &= ~POOL_MANAGE_WORKERS;
+ pool->flags |= POOL_MANAGING_WORKERS;
/*
* Destroy and then create so that may_start_working() is true
@@ -1844,6 +1846,7 @@ static bool manage_workers(struct worker *worker)
ret |= maybe_destroy_workers(pool);
ret |= maybe_create_worker(pool);
+ pool->flags &= ~POOL_MANAGING_WORKERS;
mutex_unlock(&pool->manager_mutex);
return ret;
}
--
1.7.4.4
next prev parent reply other threads:[~2012-08-29 16:50 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-29 16:51 [PATCH 0/9 V3] workqueue: fix and cleanup hotplug/rebind_workers() Lai Jiangshan
2012-08-29 16:51 ` [PATCH 1/9 V3] workqueue: ensure the wq_worker_sleeping() see the right flags Lai Jiangshan
2012-08-29 16:51 ` [PATCH 2/9 V3] workqueue: fix deadlock in rebind_workers() Lai Jiangshan
2012-08-29 16:51 ` Lai Jiangshan [this message]
2012-08-29 18:21 ` [PATCH 3/9 V3] workqueue: add POOL_MANAGING_WORKERS Tejun Heo
2012-08-30 2:38 ` Lai Jiangshan
2012-08-29 16:51 ` [PATCH 4/9 V3] workqueue: add non_manager_role_manager_mutex_unlock() Lai Jiangshan
2012-08-29 18:25 ` Tejun Heo
2012-08-30 9:16 ` Lai Jiangshan
2012-08-30 9:17 ` Tejun Heo
2012-08-31 1:08 ` Lai Jiangshan
2012-08-29 16:51 ` [PATCH 5/9 V3] workqueue: move rebind_hold to idle_rebind Lai Jiangshan
2012-08-29 16:51 ` [PATCH 6/9 V3] workqueue: simple clear WORKER_REBIND Lai Jiangshan
2012-08-29 16:51 ` [PATCH 7/9 V3] workqueue: explicit way to wait for idles workers to finish Lai Jiangshan
2012-08-29 18:34 ` Tejun Heo
2012-08-29 16:51 ` [PATCH 8/9 V3] workqueue: single pass rebind_workers Lai Jiangshan
2012-08-29 18:40 ` Tejun Heo
2012-08-29 16:52 ` [PATCH 9/9 V3] workqueue: merge the role of rebind_hold to idle_done Lai Jiangshan
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