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 <la...@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 1bfe407..979ef4f 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/