From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932495AbbFIO3n (ORCPT ); Tue, 9 Jun 2015 10:29:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52990 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752034AbbFIO3f (ORCPT ); Tue, 9 Jun 2015 10:29:35 -0400 From: Jeff Moyer To: Tejun Heo Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, vgoyal@redhat.com, avanzini.arianna@gmail.com Subject: Re: [PATCH 5/8] cfq-iosched: remove @gfp_mask from cfq_find_alloc_queue() References: <1433753973-23684-1-git-send-email-tj@kernel.org> <1433753973-23684-6-git-send-email-tj@kernel.org> <20150609030054.GJ21465@mtj.duckdns.org> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Tue, 09 Jun 2015 10:29:33 -0400 In-Reply-To: <20150609030054.GJ21465@mtj.duckdns.org> (Tejun Heo's message of "Tue, 9 Jun 2015 12:00:54 +0900") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tejun Heo writes: > Hey, Jeff. > > On Mon, Jun 08, 2015 at 04:27:10PM -0400, Jeff Moyer wrote: >> >> Remove @gfp_mask from cfq_find_alloc_queue() and propagate the changes >> >> to its callers. This simplifies the function quite a bit and will >> >> help making async queues per-cfq_group. >> > >> > Sorry, I disagree with this patch. You've changed it so that all cfqq >> > allocations are GFP_ATOMIC, and most, if not all of them simply don't >> > need to be. >> >> It occurs to me that replacing GFP_ATOMIC with GFP_NOWAIT in your patch >> would address my concerns, and patches 6-8 would apply almost as-is. >> What do you think about that? > > Oh yeah, it's okay to fail these allocations under memory pressure. > GFP_NOWAIT is the better pick here. It's GFP_ATOMIC mostly due to > historic copy&paste anyway. I'll change them to GFP_NOWAIT. OK. Assuming that's the only change, you can go ahead and add my Reviewed-by: Jeff Moyer to the next iteration. Thanks! Jeff