From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758316Ab3AQBnD (ORCPT ); Wed, 16 Jan 2013 20:43:03 -0500 Received: from mail-ie0-f180.google.com ([209.85.223.180]:41638 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758290Ab3AQBnA (ORCPT ); Wed, 16 Jan 2013 20:43:00 -0500 From: Tejun Heo To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Tejun Heo Subject: [PATCH 04/17] workqueue: make GCWQ_FREEZING a pool flag Date: Wed, 16 Jan 2013 17:42:36 -0800 Message-Id: <1358386969-945-5-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.8.0.2 In-Reply-To: <1358386969-945-1-git-send-email-tj@kernel.org> References: <1358386969-945-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make GCWQ_FREEZING a pool flag POOL_FREEZING. This patch doesn't change locking - FREEZING on both pools of a CPU are set or clear together while holding gcwq->lock. It shouldn't cause any functional difference. This leaves gcwq->flags w/o any flags. Removed. While at it, convert BUG_ON()s in freeze_workqueue_begin() and thaw_workqueues() to WARN_ON_ONCE(). This is part of an effort to remove global_cwq and make worker_pool the top level abstraction, which in turn will help implementing worker pools with user-specified attributes. Signed-off-by: Tejun Heo --- kernel/workqueue.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 8feef7e..6e8bad6 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -47,11 +47,6 @@ enum { /* - * global_cwq flags - */ - GCWQ_FREEZING = 1 << 1, /* freeze in progress */ - - /* * worker_pool flags * * A bound pool is either associated or disassociated with its CPU. @@ -70,6 +65,7 @@ enum { POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */ POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */ POOL_DISASSOCIATED = 1 << 2, /* cpu can't serve workers */ + POOL_FREEZING = 1 << 3, /* freeze in progress */ /* worker flags */ WORKER_STARTED = 1 << 0, /* started */ @@ -179,7 +175,6 @@ struct worker_pool { struct global_cwq { spinlock_t lock; /* the gcwq lock */ unsigned int cpu; /* I: the associated cpu */ - unsigned int flags; /* L: GCWQ_* flags */ /* workers are chained either in busy_hash or pool idle_list */ DECLARE_HASHTABLE(busy_hash, BUSY_WORKER_HASH_ORDER); @@ -3389,13 +3384,15 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) wq->saved_max_active = max_active; for_each_cwq_cpu(cpu, wq) { - struct global_cwq *gcwq = get_gcwq(cpu); + struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); + struct worker_pool *pool = cwq->pool; + struct global_cwq *gcwq = pool->gcwq; spin_lock_irq(&gcwq->lock); if (!(wq->flags & WQ_FREEZABLE) || - !(gcwq->flags & GCWQ_FREEZING)) - cwq_set_max_active(get_cwq(gcwq->cpu, wq), max_active); + !(pool->flags & POOL_FREEZING)) + cwq_set_max_active(cwq, max_active); spin_unlock_irq(&gcwq->lock); } @@ -3685,12 +3682,15 @@ void freeze_workqueues_begin(void) for_each_gcwq_cpu(cpu) { struct global_cwq *gcwq = get_gcwq(cpu); + struct worker_pool *pool; struct workqueue_struct *wq; spin_lock_irq(&gcwq->lock); - BUG_ON(gcwq->flags & GCWQ_FREEZING); - gcwq->flags |= GCWQ_FREEZING; + for_each_worker_pool(pool, gcwq) { + WARN_ON_ONCE(pool->flags & POOL_FREEZING); + pool->flags |= POOL_FREEZING; + } list_for_each_entry(wq, &workqueues, list) { struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); @@ -3776,8 +3776,10 @@ void thaw_workqueues(void) spin_lock_irq(&gcwq->lock); - BUG_ON(!(gcwq->flags & GCWQ_FREEZING)); - gcwq->flags &= ~GCWQ_FREEZING; + for_each_worker_pool(pool, gcwq) { + WARN_ON_ONCE(!(pool->flags & POOL_FREEZING)); + pool->flags &= ~POOL_FREEZING; + } list_for_each_entry(wq, &workqueues, list) { struct cpu_workqueue_struct *cwq = get_cwq(cpu, wq); -- 1.8.0.2