Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965746AbZLHSAw (ORCPT ); Tue, 8 Dec 2009 13:00:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965736AbZLHSAs (ORCPT ); Tue, 8 Dec 2009 13:00:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:12417 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965730AbZLHSAr (ORCPT ); Tue, 8 Dec 2009 13:00:47 -0500 From: Jeff Moyer To: Corrado Zoccolo Cc: "Linux-Kernel" , Jens Axboe , Vivek Goyal Subject: Re: [PATCH] cfq-iosched: reduce write depth only if sync was delayed References: <4b1a3d84.0d0db80a.39d0.ffff814a@mx.google.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: Tue, 08 Dec 2009 13:00:46 -0500 In-Reply-To: <4b1a3d84.0d0db80a.39d0.ffff814a@mx.google.com> (Corrado Zoccolo's message of "Fri, 4 Dec 2009 13:35:05 +0100") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 806 Lines: 22 Corrado Zoccolo writes: > The introduction of ramp-up formula for async queue depths has > slowed down dirty page reclaim, by reducing async write performance. > This patch makes sure the formula kicks in only when sync request > was recently delayed. > @@ -3706,7 +3707,7 @@ static void *cfq_init_queue(struct request_queue *q) > cfqd->cfq_latency = 1; > cfqd->cfq_group_isolation = 0; > cfqd->hw_tag = -1; > - cfqd->last_end_sync_rq = jiffies; > + cfqd->last_delayed_sync = jiffies - HZ; So, umm, what's that about? 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/