linux-kernel - Re: [PATCH 29/35] nfs: in-commit pages accounting and wait queue

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: <1292274951.8795.28.camel@heimdal.trondhjem.org>
Date:	Mon, 13 Dec 2010 16:15:51 -0500
From:	Trond Myklebust <Trond.Myklebust@...app.com>
To:	Wu Fengguang <fengguang.wu@...el.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>, Jan Kara <jack@...e.cz>,
	Christoph Hellwig <hch@....de>,
	Dave Chinner <david@...morbit.com>,
	"Theodore Ts'o" <tytso@....edu>,
	Chris Mason <chris.mason@...cle.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Mel Gorman <mel@....ul.ie>, Rik van Riel <riel@...hat.com>,
	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>,
	Greg Thelen <gthelen@...gle.com>,
	Minchan Kim <minchan.kim@...il.com>,
	linux-mm <linux-mm@...ck.org>, linux-fsdevel@...r.kernel.org,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 29/35] nfs: in-commit pages accounting and wait queue

On Mon, 2010-12-13 at 22:47 +0800, Wu Fengguang wrote:
> plain text document attachment (writeback-nfs-in-commit.patch)
> When doing 10+ concurrent dd's, I observed very bumpy commits submission
> (partly because the dd's are started at the same time, and hence reached
> 4MB to-commit pages at the same time). Basically we rely on the server
> to complete and return write/commit requests, and want both to progress
> smoothly and not consume too many pages. The write request wait queue is
> not enough as it's mainly network bounded. So add another commit request
> wait queue. Only async writes need to sleep on this queue.
> 

I'm not understanding the above reasoning. Why should we serialise
commits at the per-filesystem level (and only for non-blocking flushes
at that)?

Cheers
  Trond
-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@...app.com
www.netapp.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/