Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756898AbYFVURl (ORCPT ); Sun, 22 Jun 2008 16:17:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753749AbYFVURc (ORCPT ); Sun, 22 Jun 2008 16:17:32 -0400 Received: from casper.infradead.org ([85.118.1.10]:60056 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753733AbYFVURb (ORCPT ); Sun, 22 Jun 2008 16:17:31 -0400 Date: Sun, 22 Jun 2008 13:17:12 -0700 From: Arjan van de Ven To: paulmck@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, josh@freedesktop.org, dvhltc@us.ibm.com, niv@us.ibm.com, dino@in.ibm.com, akpm@linux-foundation.org, torvalds@linux-foundation.org, vegard.nossum@gmail.com, adobriyan@gmail.com, oleg@tv-sign.ru, bunk@kernel.org, rjw@sisk.pl Subject: Re: [PATCH -tip-rcu] Make rcutorture more vicious: make quiescent rcutorture less power-hungry Message-ID: <20080622131712.54ba732c@infradead.org> In-Reply-To: <20080622200638.GA25328@linux.vnet.ibm.com> References: <20080618122144.GA27143@linux.vnet.ibm.com> <20080618162649.GA18326@linux.vnet.ibm.com> <20080622200638.GA25328@linux.vnet.ibm.com> Organization: Intel X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1781 Lines: 47 On Sun, 22 Jun 2008 13:06:38 -0700 "Paul E. McKenney" wrote: > This patch makes the non-module rcutorture a bit more friendly to > the power-conservation code. This is a rather simple-minded approach. > More sophisticated approaches would get rid of the rcutorture tasks > while rcutorture execution was suppressed, but attempts thus far to > do this have not gone well -- calling rcu_torture_init() from a /proc > callout results in oopses. > > Signed-off-by: Paul E. McKenney > --- > > rcutorture.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff -urpNa -X dontdiff > linux-2.6.26-rc4-rcut2-proc/kernel/rcutorture.c > linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c --- > linux-2.6.26-rc4-rcut2-proc/kernel/rcutorture.c 2008-06-22 > 10:29:04.000000000 -0700 +++ > linux-2.6.26-rc4-rcut3-procq/kernel/rcutorture.c 2008-06-22 > 12:20:10.000000000 -0700 @@ -196,7 +196,10 @@ static void > rcu_stutter_wait(void) { while (stutter_pause_test > || !rcutorture_runnable) > - schedule_timeout_interruptible(1); > + if (rcutorture_runnable) > + schedule_timeout_interruptible(1); > + else > + schedule_timeout_interruptible(HZ); > } could you also make it use round_jiffies_relative() to make the power impact even less..... (by coalescing various "once a second" timers like this) -- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/