Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751175AbWBPG1m (ORCPT ); Thu, 16 Feb 2006 01:27:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751199AbWBPG1l (ORCPT ); Thu, 16 Feb 2006 01:27:41 -0500 Received: from mtagate2.de.ibm.com ([195.212.29.151]:20098 "EHLO mtagate2.de.ibm.com") by vger.kernel.org with ESMTP id S1751175AbWBPG1l (ORCPT ); Thu, 16 Feb 2006 01:27:41 -0500 Date: Thu, 16 Feb 2006 07:27:27 +0100 From: Heiko Carstens To: Andrew Morton Cc: Hannes Reinecke , linux-kernel@vger.kernel.org, Ingo Molnar Subject: Re: calibrate_migration_costs takes ages on s390 Message-ID: <20060216062727.GB9241@osiris.boeblingen.de.ibm.com> References: <20060213102634.GA4677@osiris.boeblingen.de.ibm.com> <20060213104645.GA17173@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060213104645.GA17173@elte.hu> User-Agent: mutt-ng/devel-r781 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2078 Lines: 63 > introduce the CONFIG_DEFAULT_MIGRATION_COST method for an architecture > to set the scheduler migration costs. This turns off automatic detection > of migration costs. Makes sense on virtual platforms, where migration > costs are hard to measure accurately. > > Signed-off-by: Ingo Molnar > > ---- > > arch/s390/Kconfig | 4 ++++ > kernel/sched.c | 13 ++++++++++++- > 2 files changed, 16 insertions(+), 1 deletion(-) > > Index: linux-robust-list.q/arch/s390/Kconfig > =================================================================== > --- linux-robust-list.q.orig/arch/s390/Kconfig > +++ linux-robust-list.q/arch/s390/Kconfig > @@ -80,6 +80,10 @@ config HOTPLUG_CPU > can be controlled through /sys/devices/system/cpu/cpu#. > Say N if you want to disable CPU hotplug. > > +config DEFAULT_MIGRATION_COST > + int > + default "1000000" > + > config MATHEMU > bool "IEEE FPU emulation" > depends on MARCH_G5 > Index: linux-robust-list.q/kernel/sched.c > =================================================================== > --- linux-robust-list.q.orig/kernel/sched.c > +++ linux-robust-list.q/kernel/sched.c > @@ -5159,7 +5159,18 @@ static void init_sched_build_groups(stru > #define MAX_DOMAIN_DISTANCE 32 > > static unsigned long long migration_cost[MAX_DOMAIN_DISTANCE] = > - { [ 0 ... MAX_DOMAIN_DISTANCE-1 ] = -1LL }; > + { [ 0 ... MAX_DOMAIN_DISTANCE-1 ] = > +/* > + * Architectures may override the migration cost and thus avoid > + * boot-time calibration. Unit is nanoseconds. Mostly useful for > + * virtualized hardware: > + */ > +#ifdef CONFIG_DEFAULT_MIGRATION_COST > + CONFIG_DEFAULT_MIGRATION_COST > +#else > + -1LL > +#endif > +}; > > /* > * Allow override of migration cost - in units of microseconds. > - This one should be applied then. Thanks, Heiko - 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/