From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id ED16B6B026C for ; Tue, 17 Jan 2017 18:54:29 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id 194so144110858pgd.7 for ; Tue, 17 Jan 2017 15:54:29 -0800 (PST) Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com. [2607:f8b0:400e:c05::242]) by mx.google.com with ESMTPS id e23si19274021pga.134.2017.01.17.15.54.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Jan 2017 15:54:29 -0800 (PST) Received: by mail-pg0-x242.google.com with SMTP id t6so5033586pgt.1 for ; Tue, 17 Jan 2017 15:54:29 -0800 (PST) From: Tejun Heo Subject: [PATCH 10/10] slab: use memcg_kmem_cache_wq for slab destruction operations Date: Tue, 17 Jan 2017 15:54:11 -0800 Message-Id: <20170117235411.9408-11-tj@kernel.org> In-Reply-To: <20170117235411.9408-1-tj@kernel.org> References: <20170117235411.9408-1-tj@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: vdavydov.dev@gmail.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org Cc: jsvana@fb.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, kernel-team@fb.com, Tejun Heo If there's contention on slab_mutex, queueing the per-cache destruction work item on the system_wq can unnecessarily create and tie up a lot of kworkers. Rename memcg_kmem_cache_create_wq to memcg_kmem_cache_wq and make it global and use that workqueue for the destruction work items too. While at it, convert the workqueue from an unbound workqueue to a per-cpu one with concurrency limited to 1. It's generally preferable to use per-cpu workqueues and concurrency limit of 1 is safe enough. This is suggested by Joonsoo Kim. Signed-off-by: Tejun Heo Reported-by: Jay Vana Cc: Vladimir Davydov Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 16 ++++++++-------- mm/slab_common.c | 2 +- 3 files changed, 10 insertions(+), 9 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 4de925c..67f3303 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -810,6 +810,7 @@ void memcg_kmem_uncharge(struct page *page, int order); #if defined(CONFIG_MEMCG) && !defined(CONFIG_SLOB) extern struct static_key_false memcg_kmem_enabled_key; +extern struct workqueue_struct *memcg_kmem_cache_wq; extern int memcg_nr_cache_ids; void memcg_get_cache_ids(void); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a2b20f7f..8757403 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -317,6 +317,8 @@ void memcg_put_cache_ids(void) DEFINE_STATIC_KEY_FALSE(memcg_kmem_enabled_key); EXPORT_SYMBOL(memcg_kmem_enabled_key); +struct workqueue_struct *memcg_kmem_cache_wq; + #endif /* !CONFIG_SLOB */ /** @@ -2145,8 +2147,6 @@ struct memcg_kmem_cache_create_work { struct work_struct work; }; -static struct workqueue_struct *memcg_kmem_cache_create_wq; - static void memcg_kmem_cache_create_func(struct work_struct *w) { struct memcg_kmem_cache_create_work *cw = @@ -2178,7 +2178,7 @@ static void __memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, cw->cachep = cachep; INIT_WORK(&cw->work, memcg_kmem_cache_create_func); - queue_work(memcg_kmem_cache_create_wq, &cw->work); + queue_work(memcg_kmem_cache_wq, &cw->work); } static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg, @@ -5780,12 +5780,12 @@ static int __init mem_cgroup_init(void) #ifndef CONFIG_SLOB /* * Kmem cache creation is mostly done with the slab_mutex held, - * so use a special workqueue to avoid stalling all worker - * threads in case lots of cgroups are created simultaneously. + * so use a workqueue with limited concurrency to avoid stalling + * all worker threads in case lots of cgroups are created and + * destroyed simultaneously. */ - memcg_kmem_cache_create_wq = - alloc_ordered_workqueue("memcg_kmem_cache_create", 0); - BUG_ON(!memcg_kmem_cache_create_wq); + memcg_kmem_cache_wq = alloc_workqueue("memcg_kmem_cache", 0, 1); + BUG_ON(!memcg_kmem_cache_wq); #endif cpuhp_setup_state_nocalls(CPUHP_MM_MEMCQ_DEAD, "mm/memctrl:dead", NULL, diff --git a/mm/slab_common.c b/mm/slab_common.c index 32610d1..5e6a98c 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -656,7 +656,7 @@ static void kmemcg_deactivate_rcufn(struct rcu_head *head) * initialized eariler. */ INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn); - schedule_work(&s->memcg_params.deact_work); + queue_work(memcg_kmem_cache_wq, &s->memcg_params.deact_work); } /** -- 2.9.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org