From: Tejun Heo <tj@kernel.org> To: Petr Mladek <pmladek@suse.com> Cc: cgroups@vger.kernel.org, Michal Hocko <mhocko@suse.cz>, Cyril Hrubis <chrubis@suse.cz>, linux-kernel@vger.kernel.org, Johannes Weiner <hannes@cmpxchg.org> Subject: Re: [BUG] cgroup/workques/fork: deadlock when moving cgroups Date: Wed, 13 Apr 2016 14:57:54 -0400 [thread overview] Message-ID: <20160413185754.GI3676@htj.duckdns.org> (raw) In-Reply-To: <20160413183309.GG3676@htj.duckdns.org> On Wed, Apr 13, 2016 at 02:33:09PM -0400, Tejun Heo wrote: > An easy solution would be to make lru_add_drain_all() use a > WQ_MEM_RECLAIM workqueue. A better way would be making charge moving > asynchronous similar to cpuset node migration but I don't know whether > that's realistic. Will prep a patch to add a rescuer to > lru_add_drain_all(). So, something like the following. Can you please see whether the deadlock goes away with the patch? diff --git a/mm/swap.c b/mm/swap.c index a0bc206..7022872 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -664,8 +664,16 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) lru_add_drain(); } +static struct workqueue_struct *lru_add_drain_wq; static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); +static int __init lru_add_drain_wq_init(void) +{ + lru_add_drain_wq = alloc_workqueue("lru_add_drain", WQ_MEM_RECLAIM, 0); + return lru_add_drain_wq ? 0 : -ENOMEM; +} +core_initcall(lru_add_drain_wq_init); + void lru_add_drain_all(void) { static DEFINE_MUTEX(lock); @@ -685,13 +693,12 @@ void lru_add_drain_all(void) pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) || need_activate_page_drain(cpu)) { INIT_WORK(work, lru_add_drain_per_cpu); - schedule_work_on(cpu, work); + queue_work_on(cpu, lru_add_drain_wq, work); cpumask_set_cpu(cpu, &has_work); } } - for_each_cpu(cpu, &has_work) - flush_work(&per_cpu(lru_add_drain_work, cpu)); + flush_workqueue(lru_add_drain_wq); put_online_cpus(); mutex_unlock(&lock);
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> To: Petr Mladek <pmladek-IBi9RG/b67k@public.gmane.org> Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko <mhocko-AlSwsSmVLrQ@public.gmane.org>, Cyril Hrubis <chrubis-AlSwsSmVLrQ@public.gmane.org>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Subject: Re: [BUG] cgroup/workques/fork: deadlock when moving cgroups Date: Wed, 13 Apr 2016 14:57:54 -0400 [thread overview] Message-ID: <20160413185754.GI3676@htj.duckdns.org> (raw) In-Reply-To: <20160413183309.GG3676-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org> On Wed, Apr 13, 2016 at 02:33:09PM -0400, Tejun Heo wrote: > An easy solution would be to make lru_add_drain_all() use a > WQ_MEM_RECLAIM workqueue. A better way would be making charge moving > asynchronous similar to cpuset node migration but I don't know whether > that's realistic. Will prep a patch to add a rescuer to > lru_add_drain_all(). So, something like the following. Can you please see whether the deadlock goes away with the patch? diff --git a/mm/swap.c b/mm/swap.c index a0bc206..7022872 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -664,8 +664,16 @@ static void lru_add_drain_per_cpu(struct work_struct *dummy) lru_add_drain(); } +static struct workqueue_struct *lru_add_drain_wq; static DEFINE_PER_CPU(struct work_struct, lru_add_drain_work); +static int __init lru_add_drain_wq_init(void) +{ + lru_add_drain_wq = alloc_workqueue("lru_add_drain", WQ_MEM_RECLAIM, 0); + return lru_add_drain_wq ? 0 : -ENOMEM; +} +core_initcall(lru_add_drain_wq_init); + void lru_add_drain_all(void) { static DEFINE_MUTEX(lock); @@ -685,13 +693,12 @@ void lru_add_drain_all(void) pagevec_count(&per_cpu(lru_deactivate_pvecs, cpu)) || need_activate_page_drain(cpu)) { INIT_WORK(work, lru_add_drain_per_cpu); - schedule_work_on(cpu, work); + queue_work_on(cpu, lru_add_drain_wq, work); cpumask_set_cpu(cpu, &has_work); } } - for_each_cpu(cpu, &has_work) - flush_work(&per_cpu(lru_add_drain_work, cpu)); + flush_workqueue(lru_add_drain_wq); put_online_cpus(); mutex_unlock(&lock);
next prev parent reply other threads:[~2016-04-13 18:57 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-04-13 9:42 [BUG] cgroup/workques/fork: deadlock when moving cgroups Petr Mladek 2016-04-13 18:33 ` Tejun Heo 2016-04-13 18:33 ` Tejun Heo 2016-04-13 18:57 ` Tejun Heo [this message] 2016-04-13 18:57 ` Tejun Heo 2016-04-13 19:23 ` Michal Hocko 2016-04-13 19:23 ` Michal Hocko 2016-04-13 19:28 ` Michal Hocko 2016-04-13 19:28 ` Michal Hocko 2016-04-13 19:37 ` Tejun Heo 2016-04-13 19:48 ` Michal Hocko 2016-04-14 7:06 ` Michal Hocko 2016-04-14 7:06 ` Michal Hocko 2016-04-14 15:32 ` Tejun Heo 2016-04-14 15:32 ` Tejun Heo 2016-04-14 17:50 ` Johannes Weiner 2016-04-15 7:06 ` Michal Hocko 2016-04-15 14:38 ` Tejun Heo 2016-04-15 14:38 ` Tejun Heo 2016-04-15 15:08 ` Michal Hocko 2016-04-15 15:08 ` Michal Hocko 2016-04-15 15:25 ` Tejun Heo 2016-04-15 15:25 ` Tejun Heo 2016-04-17 12:00 ` Michal Hocko 2016-04-17 12:00 ` Michal Hocko 2016-04-18 14:40 ` Petr Mladek 2016-04-18 14:40 ` Petr Mladek 2016-04-19 14:01 ` Michal Hocko 2016-04-19 14:01 ` Michal Hocko 2016-04-19 15:39 ` Petr Mladek 2016-04-15 19:17 ` [PATCH for-4.6-fixes] memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() Tejun Heo 2016-04-17 12:07 ` Michal Hocko 2016-04-17 12:07 ` Michal Hocko 2016-04-20 21:29 ` Tejun Heo 2016-04-20 21:29 ` Tejun Heo 2016-04-21 3:27 ` Michal Hocko 2016-04-21 3:27 ` Michal Hocko 2016-04-21 15:00 ` Petr Mladek 2016-04-21 15:00 ` Petr Mladek 2016-04-21 15:51 ` Tejun Heo 2016-04-21 23:06 ` [PATCH 1/2] cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback Tejun Heo 2016-04-21 23:06 ` Tejun Heo 2016-04-21 23:09 ` [PATCH 2/2] memcg: relocate charge moving from ->attach to ->post_attach Tejun Heo 2016-04-21 23:09 ` Tejun Heo 2016-04-22 13:57 ` Petr Mladek 2016-04-22 13:57 ` Petr Mladek 2016-04-25 8:25 ` Michal Hocko 2016-04-25 8:25 ` Michal Hocko 2016-04-25 19:42 ` Tejun Heo 2016-04-25 19:42 ` Tejun Heo 2016-04-25 19:44 ` Tejun Heo 2016-04-25 19:44 ` Tejun Heo 2016-04-21 23:11 ` [PATCH 1/2] cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback Tejun Heo 2016-04-21 23:11 ` Tejun Heo 2016-04-21 15:56 ` [PATCH for-4.6-fixes] memcg: remove lru_add_drain_all() invocation from mem_cgroup_move_charge() Tejun Heo 2016-04-21 15:56 ` Tejun Heo
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