From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 169DD8D003F for ; Thu, 17 Mar 2011 11:52:20 -0400 (EDT) Date: Thu, 17 Mar 2011 11:51:39 -0400 From: Christoph Hellwig Subject: Re: [PATCH RFC 0/5] IO-less balance_dirty_pages() v2 (simple approach) Message-ID: <20110317155139.GA16195@infradead.org> References: <1299623475-5512-1-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Curt Wohlgemuth Cc: Jan Kara , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Wu Fengguang , Peter Zijlstra , Andrew Morton On Thu, Mar 17, 2011 at 08:46:23AM -0700, Curt Wohlgemuth wrote: > But if one of one's goals is to provide some sort of disk isolation based on > cgroup parameters, than having at most one stream of write requests > effectively neuters the IO scheduler. If you use any kind of buffered I/O you already fail in that respect. Writeback from balance_dirty_page really is just the wort case right now with more I/O supposed to be handled by the background threads. So if you want to implement isolation properly you need to track the originator of the I/O between the copy to the pagecache and actual writeback. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org