From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id BA83D6B01F4 for ; Mon, 16 Aug 2010 22:41:43 -0400 (EDT) Date: Tue, 17 Aug 2010 10:41:40 +0800 From: Wu Fengguang Subject: Re: [RFC][PATCH] Per file dirty limit throttling Message-ID: <20100817024140.GB13916@localhost> References: <201008160949.51512.knikanth@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201008160949.51512.knikanth@suse.de> Sender: owner-linux-mm@kvack.org To: Nikanth Karthikesan Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Jens Axboe , Andrew Morton , Jan Kara , Peter Zijlstra , Trond Myklebust , Peter Staubach List-ID: On Mon, Aug 16, 2010 at 12:19:50PM +0800, Nikanth Karthikesan wrote: > When the total dirty pages exceed vm_dirty_ratio, the dirtier is made to do > the writeback. But this dirtier may not be the one who took the system to this > state. Instead, if we can track the dirty count per-file, we could throttle > the dirtier of a file, when the file's dirty pages exceed a certain limit. > Even though this dirtier may not be the one who dirtied the other pages of > this file, it is fair to throttle this process, as it uses that file. Nikanth, there's a more elegant solution in upstream kernel. See the comment for task_dirty_limit() in commit 1babe1838. NFS may want to limit per-file dirty pages, to prevent long stall time inside the nfs_getattr()->filemap_write_and_wait() calls (and problems like that). Peter Staubach has similar ideas on it. Thanks, Fengguang -- 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