From: Johannes Weiner <hannes@cmpxchg.org>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>, Michal Hocko <mhocko@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
cgroups@vger.kernel.org
Subject: Re: [patch v2] mm, memcg: periodically schedule when emptying page list
Date: Mon, 2 Jun 2014 21:15:10 -0400 [thread overview]
Message-ID: <20140603011510.GO2878@cmpxchg.org> (raw)
In-Reply-To: <alpine.DEB.2.02.1406021749590.13910@chino.kir.corp.google.com>
On Mon, Jun 02, 2014 at 05:51:25PM -0700, David Rientjes wrote:
> From: Hugh Dickins <hughd@google.com>
>
> mem_cgroup_force_empty_list() can iterate a large number of pages on an lru and
> mem_cgroup_move_parent() doesn't return an errno unless certain criteria, none
> of which indicate that the iteration may be taking too long, is met.
>
> We have encountered the following stack trace many times indicating
> "need_resched set for > 51000020 ns (51 ticks) without schedule", for example:
>
> scheduler_tick()
> <timer irq>
> mem_cgroup_move_account+0x4d/0x1d5
> mem_cgroup_move_parent+0x8d/0x109
> mem_cgroup_reparent_charges+0x149/0x2ba
> mem_cgroup_css_offline+0xeb/0x11b
> cgroup_offline_fn+0x68/0x16b
> process_one_work+0x129/0x350
>
> If this iteration is taking too long, we still need to do cond_resched() even
> when an individual page is not busy.
>
> [rientjes@google.com: changelog]
> Signed-off-by: Hugh Dickins <hughd@google.com>
> Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
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next prev parent reply other threads:[~2014-06-03 1:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-02 23:13 [patch] " David Rientjes
2014-06-02 23:44 ` Hugh Dickins
2014-06-02 23:48 ` David Rientjes
2014-06-03 0:01 ` Hugh Dickins
2014-06-03 0:51 ` [patch v2] " David Rientjes
2014-06-03 1:15 ` Johannes Weiner [this message]
2014-06-03 6:27 ` Michal Hocko
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