From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <400644314.11994@ustc.edu.cn> Date: Fri, 18 Jan 2008 14:01:14 +0800 From: Fengguang Wu Subject: Re: [patch] Converting writeback linked lists to a tree based data structure References: <20080115080921.70E3810653@localhost> <400562938.07583@ustc.edu.cn> <532480950801171307q4b540ewa3acb6bfbea5dbc8@mail.gmail.com> <400632190.14601@ustc.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Message-Id: Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Michael Rubin , a.p.zijlstra@chello.nl, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, Jan 18, 2008 at 06:41:09AM +0100, Andi Kleen wrote: > Fengguang Wu writes: > > > > Suppose we want to grant longer expiration window for temp files, > > adding a new list named s_dirty_tmpfile would be a handy solution. > > How would the kernel know that a file is a tmp file? No idea - but it makes a good example ;-) But for those making different filesystems for /tmp, /var, /data etc, per-superblock expiration parameters may help. > > So the question is: should we need more than 3 QoS classes? > > [just a random idea; i have not worked out all the implications] > > Would it be possible to derive a writeback apriority from the ionice > level of the process originating the IO? e.g. we have long standing > problems that background jobs even when niced and can cause > significant slow downs to foreground processes by starving IO > and pushing out pages. ionice was supposed to help with that > but in practice it does not seem to have helped too much and I suspect > it needs more prioritization higher up the VM food chain. Adding > such priorities to writeback would seem like a step in the right > direction, although it would of course not solve the problem > completely. Good idea. Michael may well be considering similar interfaces :-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org