From: Roman Gushchin <guro@fb.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Kernel Team <Kernel-team@fb.com>,
"Shakeel Butt" <shakeelb@google.com>,
Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
Rik van Riel <riel@surriel.com>,
Konstantin Khlebnikov <koct9i@gmail.com>,
Matthew Wilcox <willy@infradead.org>,
"Stable@vger.kernel.org" <Stable@vger.kernel.org>
Subject: Re: Will the recent memory leak fixes be backported to longterm kernels?
Date: Fri, 2 Nov 2018 15:48:57 +0000 [thread overview]
Message-ID: <20181102154844.GA17619@tower.DHCP.thefacebook.com> (raw)
In-Reply-To: <20181102073009.GP23921@dhcp22.suse.cz>
On Fri, Nov 02, 2018 at 09:03:55AM +0100, Michal Hocko wrote:
> On Fri 02-11-18 02:45:42, Dexuan Cui wrote:
> [...]
> > I totally agree. I'm now just wondering if there is any temporary workaround,
> > even if that means we have to run the kernel with some features disabled or
> > with a suboptimal performance?
>
> One way would be to disable kmem accounting (cgroup.memory=nokmem kernel
> option). That would reduce the memory isolation because quite a lot of
> memory will not be accounted for but the primary source of in-flight and
> hard to reclaim memory will be gone.
In my experience disabling the kmem accounting doesn't really solve the issue
(without patches), but can lower the rate of the leak.
>
> Another workaround could be to use force_empty knob we have in v1 and
> use it when removing a cgroup. We do not have it in cgroup v2 though.
> The file hasn't been added to v2 because we didn't really have any
> proper usecase. Working around a bug doesn't sound like a _proper_
> usecase but I can imagine workloads that bring a lot of metadata objects
> that are not really interesting for later use so something like a
> targeted drop_caches...
This can help a bit too, but even using the system-wide drop_caches knob
unfortunately doesn't return all the memory back.
Thanks!
next prev parent reply other threads:[~2018-11-02 15:49 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-02 0:16 Will the recent memory leak fixes be backported to longterm kernels? Dexuan Cui
2018-11-02 0:45 ` Sasha Levin
2018-11-02 0:58 ` Roman Gushchin
2018-11-02 2:45 ` Dexuan Cui
2018-11-02 3:16 ` Roman Gushchin
2018-11-02 8:03 ` Michal Hocko
2018-11-02 15:48 ` Roman Gushchin [this message]
2018-11-02 16:13 ` Michal Hocko
2018-11-02 16:22 ` Roman Gushchin
2018-11-02 16:51 ` Michal Hocko
2018-11-02 17:25 ` Roman Gushchin
2018-11-02 17:48 ` Michal Hocko
2018-11-02 19:38 ` Roman Gushchin
2018-11-05 9:21 ` Michal Hocko
2018-12-28 10:50 ` Greg KH
2019-01-30 0:23 ` Sasha Levin
2019-01-30 5:58 ` Roman Gushchin
2018-11-02 16:01 ` Sasha Levin
2018-11-04 9:16 ` Mike Rapoport
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