Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbZLELNc (ORCPT ); Sat, 5 Dec 2009 06:13:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754090AbZLELNc (ORCPT ); Sat, 5 Dec 2009 06:13:32 -0500 Received: from mail-yw0-f198.google.com ([209.85.211.198]:44902 "EHLO mail-yw0-f198.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753864AbZLELNb convert rfc822-to-8bit (ORCPT ); Sat, 5 Dec 2009 06:13:31 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=W602+2UU5H3OGMkiAyDecyblArspN2z3+eoKPCIz6OBGzDFcKU8sTTBptVsYhBGaYE tQgFQwpA5y8V5RIX2rvd1jUwg/NJw5/Csc3AlY0wL95p7iy3NDCtvqa+kRqHLTd4fl5U prMuVhDjwMDD3xuJ3FTc8dmr8tnjgJXDyHaw0= MIME-Version: 1.0 In-Reply-To: <4b1a3d84.0d0db80a.39d0.ffff814a@mx.google.com> References: <4b1a3d84.0d0db80a.39d0.ffff814a@mx.google.com> Date: Sat, 5 Dec 2009 12:13:37 +0100 Message-ID: <4e5e476b0912050313k280caa8bjf7c2cf1c5d19c88c@mail.gmail.com> Subject: Re: [PATCH] cfq-iosched: reduce write depth only if sync was delayed From: Corrado Zoccolo To: Linux-Kernel , Jens Axboe , Jeff Moyer , Vivek Goyal Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2502 Lines: 68 On Fri, Dec 4, 2009 at 1:35 PM, Corrado Zoccolo wrote: > 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. > > Signed-off-by: Corrado Zoccolo > --- >  block/cfq-iosched.c |    9 +++++---- >  1 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c > index b00ca4c..a594388 100644 > --- a/block/cfq-iosched.c > +++ b/block/cfq-iosched.c > @@ -284,7 +284,7 @@ struct cfq_data { >         */ >        struct cfq_queue oom_cfqq; > > -       unsigned long last_end_sync_rq; > +       unsigned long last_delayed_sync; > >        /* List of cfq groups being managed on this device*/ >        struct hlist_head cfqg_list; > @@ -2264,7 +2264,7 @@ static bool cfq_may_dispatch(struct cfq_data *cfqd, > struct cfq_queue *cfqq) >         * based on the last sync IO we serviced >         */ >        if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { > -               unsigned long last_sync = jiffies - cfqd->last_end_sync_rq; > +               unsigned long last_sync = jiffies - cfqd->last_delayed_sync; >                unsigned int depth; > >                depth = last_sync / cfqd->cfq_slice[1]; > @@ -3272,7 +3272,8 @@ static void cfq_completed_request(struct request_queue > *q, struct request *rq) > >        if (sync) { >                RQ_CIC(rq)->last_end_request = now; > -               cfqd->last_end_sync_rq = now; > +               if (time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) > +                       cfqd->last_delayed_sync = now; Sorry, the check be reversed (!time_after). >        } > >        /* > @@ -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; >        return cfqd; >  } > > -- > 1.6.2.5 > > > > -- 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/