linux-kernel - Re: writeout stalls in current -git

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: <64bb37e0711061226l48dce395ub2f9539efc66ecc0@mail.gmail.com>
Date:	Tue, 6 Nov 2007 21:26:05 +0100
From:	"Torsten Kaiser" <just.for.lkml@...glemail.com>
To:	"Peter Zijlstra" <peterz@...radead.org>
Cc:	"David Chinner" <dgc@....com>,
	"Fengguang Wu" <wfg@...l.ustc.edu.cn>,
	"Maxim Levitsky" <maximlevitsky@...il.com>,
	linux-kernel@...r.kernel.org,
	"Andrew Morton" <akpm@...ux-foundation.org>,
	linux-fsdevel@...r.kernel.org, xfs@....sgi.com
Subject: Re: writeout stalls in current -git

On 11/6/07, Peter Zijlstra <peterz@...radead.org> wrote:
> On Tue, 2007-11-06 at 15:25 +1100, David Chinner wrote:
>
> > I'm struggling to understand what possible changed in XFS or writeback that
> > would lead to stalls like this, esp. as you appear to be removing files when
> > the stalls occur.
>
> Just a crazy idea,..
>
> Could there be a set_page_dirty() that doesn't have
> balance_dirty_pages() call near? For example modifying meta data in
> unlink?
>
> Such a situation could lead to an excess of dirty pages and the next
> call to balance_dirty_pages() would appear to stall, as it would
> desperately try to get below the limit again.

Only if accounting of the dirty pages is also broken.
In the unmerge testcase I see most of the time only <200kb of dirty
data in /proc/meminfo.

The system has 4Gb of RAM so I'm not sure if it should ever be valid
to stall even the emerge/install testcase.

Torsten

Now building a kernel with the skipped-pages-accounting-patch reverted...
-
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/