linux-kernel - Re: [PATCH v5] mm: Add memory allocation watchdog kernel thread.

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] [day] [month] [year] [list]

Message-ID: <20160512163824.GA4940@dhcp22.suse.cz>
Date:	Thu, 12 May 2016 18:38:25 +0200
From:	Michal Hocko <mhocko@...nel.org>
To:	Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
Cc:	hillf.zj@...baba-inc.com, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: Re: [PATCH v5] mm: Add memory allocation watchdog kernel thread.

On Fri 13-05-16 00:09:07, Tetsuo Handa wrote:
[...]
> Michal, this version eliminated overhead of walking the process list
> when nothing is wrong. You are aware of the possibility of
> debug_show_all_locks() failing to report the culprit, aren't you?
> So, what are unacceptable major problems for you?

I do not remember complaining about anything unacceptable for this
patch. I just thought it was way too large the last time I have looked
at it. Johannes was suggesting to simply extend warn_alloc_failed to
also report too many retries with some extended information as a more
lightweight approach.  It wouldn't give as much information as your
watchdog but maybe it would be sufficient to figure out that something
really bad is going on. Dunno but I would rather see a more lightweight
debugging aid than a lot of code which sit basically unused most of the
time.

That being said I cannot comment on this particular version as I haven't
checked it properly yet.
-- 
Michal Hocko
SUSE Labs