linux-kernel - Re: [PATCH for 3.2.34] memcg: do not trigger OOM from add_to_page_cache

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 28 Dec 2012 17:35:21 +0100
From:	Michal Hocko <mhocko@...e.cz>
To:	azurIt <azurit@...ox.sk>
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	cgroups mailinglist <cgroups@...r.kernel.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Johannes Weiner <hannes@...xchg.org>
Subject: Re: [PATCH for 3.2.34] memcg: do not trigger OOM from
 add_to_page_cache_locked

On Mon 24-12-12 14:38:50, azurIt wrote:
> >OK, good to hear and fingers crossed. I will try to get back to the
> >original problem and a better solution sometimes early next year when
> >all the things settle a bit.
> 
> 
> Btw, i noticed one more thing when problem is happening (=when any
> cgroup is stucked), i fogot to mention it before, sorry :( . It's
> related to HDDs, something is slowing them down in a strange way. All
> services are working normally and i really cannot notice any slowness,
> the only thing which i noticed is affeceted is our backup software (
> www.Bacula.org ). When problem occurs at night, so it's happening when
> backup is running, backup is extremely slow and usually don't finish
> until i kill processes inside affected cgroup (=until i resolve the
> problem). Backup software is NOT doing big HDD bandwidth BUT it's
> doing quite huge number of disk operations (it needs to stat every
> file and directory). I believe that only speed of disk operations are
> affected and are very slow.

I would bet that this is caused by the blocked proceses in memcg oom
handler which hold i_mutex and the backup process wants to access the
same inode with an operation which requires the lock.
-- 
Michal Hocko
SUSE Labs
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/