linux-kernel - Re: [PATCH 1/2] vmscan: fix initial shrinker size handling

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:	Tue, 23 Aug 2011 09:28:34 +1000
From:	Dave Chinner <david@...morbit.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Konstantin Khlebnikov <khlebnikov@...nvz.org>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] vmscan: fix initial shrinker size handling

On Mon, Aug 22, 2011 at 02:30:06PM -0700, Andrew Morton wrote:
> On Mon, 22 Aug 2011 14:17:21 +0300
> Konstantin Khlebnikov <khlebnikov@...nvz.org> wrote:
> 
> > Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock.
> > For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0.
> > Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this,
> > and next time this shrinker can get really big pressure. Let's skip such shrinkers instead.
> 
> Yes, that looks like a significant oversight.
> 
> > Also make total_scan signed, otherwise check (total_scan < 0) below never works.
> 
> Hopefully a smaller oversight.

Yeah, it was, but is harmless because it is caught by the next check
of total_scanned. I've made similar "make everything signed" changes
as well.

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com
--
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/