From mboxrd@z Thu Jan 1 00:00:00 1970 From: OGAWA Hirofumi Subject: Re: [PATCH 0/7] Discard requests, v2 Date: Sun, 10 Aug 2008 07:48:08 +0900 Message-ID: <87abflrejb.fsf@devron.myhome.or.jp> References: <1218299181.26926.88.camel@pmac.infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jens Axboe , Andrew Morton , Ric Wheeler , linux-fsdevel@vger.kernel.org, gilad@codefidence.com, matthew@wil.cx To: David Woodhouse Return-path: Received: from mail.parknet.ad.jp ([210.171.162.6]:55271 "EHLO mail.officemail.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752618AbYHIWsP (ORCPT ); Sat, 9 Aug 2008 18:48:15 -0400 In-Reply-To: <1218299181.26926.88.camel@pmac.infradead.org> (David Woodhouse's message of "Sat, 09 Aug 2008 17:26:21 +0100") Sender: linux-fsdevel-owner@vger.kernel.org List-ID: David Woodhouse writes: > This time on top of the for-2.6.28 branch of > git://git.kernel.dk/linux-2.6-block.git > > I've made it cope with merging and sorting discard requests, still as a > separate patch at the end of the sequence. I don't think we have a > problem with discards passing writes in the queue, any more than we > _already_ had a problem with writes passing writes. > > I've at least made elv_dispatch_sort() prevent discard requests from > passing read/write requests, just as it already prevented read and write > requests from passing each other. I wonder about I/O schedule impact... Currently it seems we schedule data direction as READ (no flags). Although I'm not sure, we might want to schedule it as WRITE? (I guess WRITE can be allowed delay more than READ...) Thanks. -- OGAWA Hirofumi