Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755105Ab1C3ICL (ORCPT ); Wed, 30 Mar 2011 04:02:11 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:53812 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752641Ab1C3ICI (ORCPT ); Wed, 30 Mar 2011 04:02:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=gfsxHnAfKYJE6JG9zc6SALa7BxS0n85i7LR/lxtkuyjsEI9HwtAiLTG22iNJG435KI YPgzDEUhqBh8Zy7e11lTYd64MoPmivOMfHIhGZE90nRQZIMZ2ZBSYd4b3P3guvP+lRp1 7YEps6PqimRBhshA67Bdl1ouquKwYNTj1pyHE= Date: Wed, 30 Mar 2011 10:02:03 +0200 From: Tejun Heo To: Jens Axboe Cc: Vivek Goyal , Jeff Moyer , Mike Snitzer , Markus Trippelsdorf , Sergey Senozhatsky , linux-kernel@vger.kernel.org, Chris Mason Subject: Re: [PATCH] block: eliminate ELEVATOR_INSERT_REQUEUE Message-ID: <20110330080203.GD17523@htj.dyndns.org> References: <20110325185455.GA2969@redhat.com> <4D8CF202.9010809@kernel.dk> <20110326042156.GB28458@redhat.com> <20110328082321.GC16530@htj.dyndns.org> <20110328221547.GA1118@redhat.com> <20110329175458.GE24485@redhat.com> <20110330074123.GA17523@htj.dyndns.org> <20110330075752.GC17523@htj.dyndns.org> <4D92E2CD.6000909@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D92E2CD.6000909@kernel.dk> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 866 Lines: 23 Hello, Jens. On Wed, Mar 30, 2011 at 09:59:09AM +0200, Jens Axboe wrote: > Pure front insert should be used for requeue and internal commands (like > spin up this drive, or get error information). Flush should append to > the dispatch list. Yeah, right. The reason I used REQUEUE/FRONT was because BACK insertion involves draining the elevator and then appending the request at the end of the dispatch queue, which is unnecessary and inefficient. So, front insertion was a quick work around that. If we're removing elv_insert(), we can just append directly to the dispatch queue from flush code. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/