linux-kernel - Re: [PATCH 3/5] writeback: dirty rate control

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:	Wed, 10 Aug 2011 19:10:26 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Wu Fengguang <fengguang.wu@...el.com>
Cc:	Vivek Goyal <vgoyal@...hat.com>,
	"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Jan Kara <jack@...e.cz>, Christoph Hellwig <hch@....de>,
	Dave Chinner <david@...morbit.com>,
	Greg Thelen <gthelen@...gle.com>,
	Minchan Kim <minchan.kim@...il.com>,
	Andrea Righi <arighi@...eler.com>,
	linux-mm <linux-mm@...ck.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/5] writeback: dirty rate control

On Wed, 2011-08-10 at 22:00 +0800, Wu Fengguang wrote:
> 
> > Although I'm not quite sure how he keeps fairness in light of the
> > sleep time bounding to MAX_PAUSE.
> 
> Firstly, MAX_PAUSE will only be applied when the dirty pages rush
> high (dirty exceeded).  Secondly, the dirty exceeded state is global
> to all tasks, in which case each task will sleep for MAX_PAUSE equally.
> So the fairness is still maintained in dirty exceeded state. 

Its not immediately apparent how dirty_exceeded and MAX_PAUSE interact,
but having everybody sleep MAX_PAUSE doesn't necessarily mean its fair,
its only fair if they dirty at the same rate.
--
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/