Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756475Ab0LMAj5 (ORCPT ); Sun, 12 Dec 2010 19:39:57 -0500 Received: from mga02.intel.com ([134.134.136.20]:37217 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753640Ab0LMAjz (ORCPT ); Sun, 12 Dec 2010 19:39:55 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,333,1288594800"; d="scan'208";a="686445909" Subject: Re: [patch]block cfq: select new workload if priority changed From: Shaohua Li To: Jeff Moyer Cc: lkml , Jens Axboe , "czoccolo@gmail.com" In-Reply-To: References: <1291871853.2323.8.camel@sli10-conroe> Content-Type: text/plain; charset="UTF-8" Date: Mon, 13 Dec 2010 08:39:52 +0800 Message-ID: <1292200792.2323.13.camel@sli10-conroe> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2309 Lines: 71 On Fri, 2010-12-10 at 22:56 +0800, Jeff Moyer wrote: > Shaohua Li writes: > > > If priority is changed, continue checking workload_expires and service tree > > count of previous workload is meaningless. We should always choose the workload > > I'd change that first sentence to: > > If priority is changed, continuing to check workload_expires and > service tree count of the previous workload does not make sense. > > > with lowest key of new priority in such case. > > > > Signed-off-by: Shaohua Li > > This makes sense to me. > > Reviewed-by: Jeff Moyer Thanks, modified the the changelog. If priority is changed, continuing to check workload_expires and service tree count of the previous workload does not make sense. We should always choose the workload with lowest key of new priority in such case. Signed-off-by: Shaohua Li Reviewed-by: Jeff Moyer --- block/cfq-iosched.c | 5 +++++ 1 file changed, 5 insertions(+) Index: linux/block/cfq-iosched.c =================================================================== --- linux.orig/block/cfq-iosched.c 2010-12-08 19:39:01.000000000 +0800 +++ linux/block/cfq-iosched.c 2010-12-09 10:27:24.000000000 +0800 @@ -2116,6 +2116,7 @@ static void choose_service_tree(struct c unsigned count; struct cfq_rb_root *st; unsigned group_slice; + enum wl_prio_t original_prio = cfqd->serving_prio; if (!cfqg) { cfqd->serving_prio = IDLE_WORKLOAD; @@ -2134,6 +2135,9 @@ static void choose_service_tree(struct c return; } + if (original_prio != cfqd->serving_prio) + goto new_workload; + /* * For RT and BE, we have to choose also the type * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload @@ -2148,6 +2152,7 @@ static void choose_service_tree(struct c if (count && !time_after(jiffies, cfqd->workload_expires)) return; +new_workload: /* otherwise select new workload type */ cfqd->serving_type = cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); -- 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/