From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754114Ab2ASLMA (ORCPT ); Thu, 19 Jan 2012 06:12:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:15646 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750848Ab2ASLL7 (ORCPT ); Thu, 19 Jan 2012 06:11:59 -0500 Date: Thu, 19 Jan 2012 06:11:51 -0500 From: Vivek Goyal To: Tejun Heo Cc: axboe@kernel.dk, ctalbott@google.com, rni@google.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 04/12] elevator: make elevator_init_fn() return 0/-errno Message-ID: <20120119111151.GC2649@redhat.com> References: <1326935490-11827-1-git-send-email-tj@kernel.org> <1326935490-11827-5-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1326935490-11827-5-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 18, 2012 at 05:11:22PM -0800, Tejun Heo wrote: > elevator_ops->elevator_init_fn() has a weird return value. It returns > a void * which the caller should assign to q->elevator->elevator_data > and %NULL return denotes init failure. > > Update such that it returns integer 0/-errno and sets elevator_data > directly as necessary. > kmalloc() does the same thing. returning pointer means success and null means failure. Also elevator initialization might not necessarily mean that you are the active elevator. So cfq_init_queue() assuming that I am the active elevator and setting up q->elevator->elevator_data sounds odd to me. Personally, I liked previous interface better. But, let me read rest of the patches and see how you have made use of it to do more cleanup. Thanks Vivek