Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030184AbWCQOLS (ORCPT ); Fri, 17 Mar 2006 09:11:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030189AbWCQOLR (ORCPT ); Fri, 17 Mar 2006 09:11:17 -0500 Received: from mail16.syd.optusnet.com.au ([211.29.132.197]:47307 "EHLO mail16.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S1030184AbWCQOLR (ORCPT ); Fri, 17 Mar 2006 09:11:17 -0500 From: Con Kolivas To: Nick Piggin Subject: Re: [PATCH] sched: activate SCHED BATCH expired Date: Sat, 18 Mar 2006 01:11:00 +1100 User-Agent: KMail/1.9.1 Cc: Ingo Molnar , ck@vds.kolivas.org, Andrew Morton , linux-kernel@vger.kernel.org References: <200603081013.44678.kernel@kolivas.org> <200603180036.11326.kernel@kolivas.org> <441ABD9F.6060407@yahoo.com.au> In-Reply-To: <441ABD9F.6060407@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603180111.01466.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2686 Lines: 77 On Saturday 18 March 2006 00:46, Nick Piggin wrote: > I guess it isn't doing the cmov because it doesn't want to do the > extra load in the common case, which is fair enough (are you compiling > for a pentiumpro+, without generic x86 support? For pentium4 with no generic support. > what about if you > turn off optimise for size?) Dunno, sleep is taking me... > At least other archtectures might be able to make better use of it, > and I agree even for i386 the code looks better (and slightly smaller). Good enough for me. Here's a respin, thanks! Cheers, Con --- To increase the strength of SCHED_BATCH as a scheduling hint we can activate batch tasks on the expired array since by definition they are latency insensitive tasks. Signed-off-by: Con Kolivas --- include/linux/sched.h | 1 + kernel/sched.c | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) Index: linux-2.6.16-rc6-mm1/include/linux/sched.h =================================================================== --- linux-2.6.16-rc6-mm1.orig/include/linux/sched.h 2006-03-13 20:12:22.000000000 +1100 +++ linux-2.6.16-rc6-mm1/include/linux/sched.h 2006-03-17 23:08:31.000000000 +1100 @@ -485,6 +485,7 @@ struct signal_struct { #define MAX_PRIO (MAX_RT_PRIO + 40) #define rt_task(p) (unlikely((p)->prio < MAX_RT_PRIO)) +#define batch_task(p) (unlikely((p)->policy == SCHED_BATCH)) /* * Some day this will be a full-fledged user tracking system.. Index: linux-2.6.16-rc6-mm1/kernel/sched.c =================================================================== --- linux-2.6.16-rc6-mm1.orig/kernel/sched.c 2006-03-13 20:12:15.000000000 +1100 +++ linux-2.6.16-rc6-mm1/kernel/sched.c 2006-03-18 01:05:02.000000000 +1100 @@ -737,9 +737,13 @@ static inline void dec_nr_running(task_t /* * __activate_task - move a task to the runqueue. */ -static inline void __activate_task(task_t *p, runqueue_t *rq) +static void __activate_task(task_t *p, runqueue_t *rq) { - enqueue_task(p, rq->active); + prio_array_t *target = rq->active; + + if (batch_task(p)) + target = rq->expired; + enqueue_task(p, target); inc_nr_running(p, rq); } @@ -758,7 +762,7 @@ static int recalc_task_prio(task_t *p, u unsigned long long __sleep_time = now - p->timestamp; unsigned long sleep_time; - if (unlikely(p->policy == SCHED_BATCH)) + if (batch_task(p)) sleep_time = 0; else { if (__sleep_time > NS_MAX_SLEEP_AVG) - 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/