From e6a9a7712331b9d2f551cad8630f6a6c6428c721 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 3 Jun 2014 15:32:07 +0800 Subject: [PATCH] workqueue: remove the empty check in too_many_workers() The commit ea1abd6197d5 ("workqueue: reimplement idle worker rebinding") used a trick which simply removes all to-be-bound idle workers from the idle list and lets them add themselves back after completing rebinding. And this trick caused the @worker_pool->nr_idle may deviate than the actual number of idle workers on @worker_pool->idle_list. More specifically, nr_idle may be non-zero while ->idle_list is empty. All users of ->nr_idle and ->idle_list are audited. The only affected one is too_many_workers() which is updated to check %false if ->idle_list is empty regardless of ->nr_idle. The commit/trick was complicated due to it just tried to simplify an even more complicated problem (workers had to rebind itself). But the commit a9ab775bcadf ("workqueue: directly restore CPU affinity of workers from CPU_ONLINE") fixed all these problems and the mentioned trick was useless and is gone. So, now the @worker_pool->nr_idle is exactly the actual number of workers on @worker_pool->idle_list. too_many_workers() should recover as it was before the trick. So we remove the empty check. Signed-off-by: Lai Jiangshan Signed-off-by: Tejun Heo --- kernel/workqueue.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ea2c5de502aa..170b724b2d69 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -758,13 +758,6 @@ static bool too_many_workers(struct worker_pool *pool) int nr_idle = pool->nr_idle + managing; /* manager is considered idle */ int nr_busy = pool->nr_workers - nr_idle; - /* - * nr_idle and idle_list may disagree if idle rebinding is in - * progress. Never return %true if idle_list is empty. - */ - if (list_empty(&pool->idle_list)) - return false; - return nr_idle > 2 && (nr_idle - 2) * MAX_IDLE_WORKERS_RATIO >= nr_busy; }