Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751949AbbEASHv (ORCPT ); Fri, 1 May 2015 14:07:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45108 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750812AbbEASHu (ORCPT ); Fri, 1 May 2015 14:07:50 -0400 From: Jeff Moyer To: Shaohua Li Cc: , , , Subject: Re: [PATCH 2/5] sched: always use blk_schedule_flush_plug in io_schedule_out References: <9eedafbfb33bf3e8d273860e75f9f07ca9b0d5ec.1430414610.git.shli@fb.com> 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: Fri, 01 May 2015 14:07:42 -0400 In-Reply-To: (Jeff Moyer's message of "Fri, 01 May 2015 13:42:02 -0400") 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 Content-Length: 1215 Lines: 31 Jeff Moyer writes: > Shaohua Li writes: > >> block plug callback could sleep, so we introduce a parameter >> 'from_schedule' and corresponding drivers can use it to destinguish a >> schedule plug flush or a plug finish. Unfortunately io_schedule_out >> still uses blk_flush_plug(). This causes below output (Note, I added a >> might_sleep() in raid1_unplug to make it trigger faster, but the whole >> thing doesn't matter if I add might_sleep). In raid1/10, this can cause >> deadlock. >> >> This patch makes io_schedule_out always uses blk_schedule_flush_plug. >> This should only impact drivers (as far as I know, raid 1/10) which are >> sensitive to the 'from_schedule' parameter. > > Why wouldn't you change io_schedule_timeout to use blk_flush_plug_list > instead? Sorry, I did not fully engage my brain on this one. I see that's exactly what you did. I'll add my reviewed-by once you've addressed hch's concern. Cheers, Jeff -- 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/