linux-kernel - Re: regression caused by cgroups optimization in 3.17-rc2

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]

Message-ID: <5406262F.4050705@intel.com>
Date:	Tue, 02 Sep 2014 13:18:55 -0700
From:	Dave Hansen <dave.hansen@...el.com>
To:	Dave Hansen <dave@...1.net>, Johannes Weiner <hannes@...xchg.org>,
	Michal Hocko <mhocko@...e.com>,
	Hugh Dickins <hughd@...gle.com>, Tejun Heo <tj@...nel.org>,
	Vladimir Davydov <vdavydov@...allels.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux-MM <linux-mm@...ck.org>
Subject: Re: regression caused by cgroups optimization in 3.17-rc2

On 09/02/2014 12:05 PM, Dave Hansen wrote:
> It does not revert cleanly because of the hunks below.  The code in
> those hunks was removed, so I tried running without properly merging
> them and it spews warnings because counter->usage is seen going negative.
> 
> So, it doesn't appear we can quickly revert this.

I'm fairly confident that I missed some of the cases (especially in the
charge-moving code), but the attached patch does at least work around
the regression for me.  It restores the original performance, or at
least gets _close_ to it.



View attachment "try-partial-revert-of-root-charge-regression-patch.patch" of type "text/x-patch" (1516 bytes)