From owner-freebsd-hackers@FreeBSD.ORG Sat Jul 24 17:13:23 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 920751065670; Sat, 24 Jul 2010 17:13:23 +0000 (UTC) (envelope-from rpaulo@lavabit.com) Received: from karen.lavabit.com (karen.lavabit.com [72.249.41.33]) by mx1.freebsd.org (Postfix) with ESMTP id 4E55D8FC0A; Sat, 24 Jul 2010 17:13:23 +0000 (UTC) Received: from e.earth.lavabit.com (e.earth.lavabit.com [192.168.111.14]) by karen.lavabit.com (Postfix) with ESMTP id 553E6157557; Sat, 24 Jul 2010 11:18:57 -0500 (CDT) Received: from 10.0.10.3 (54.81.54.77.rev.vodafone.pt [77.54.81.54]) by lavabit.com with ESMTP id L8XA8AD94AJ4; Sat, 24 Jul 2010 11:18:57 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=lavabit; d=lavabit.com; b=l+aMJL/LfnbeJ4XKHCZDtoUzIETWHdqkMTjbIYyf+Y0qEfv22Y87QBYyjw0WbrYy07rcoLBX4xOed9QOiUB0lfuZLIc+hVSHzvtrM5RfOom4LgblcSg2q6ARcDytXCKNOkFNkUjJU2pcVDiljGBn0C++4tJdCn/Bks1Ko26ME8Y=; h=Subject:Mime-Version:Content-Type:From:In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References:To:X-Mailer; Mime-Version: 1.0 (Apple Message framework v1081) Content-Type: text/plain; charset=us-ascii From: Rui Paulo In-Reply-To: <4C4AF046.40507@FreeBSD.org> Date: Sat, 24 Jul 2010 17:18:53 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <4C4AF046.40507@FreeBSD.org> To: Alexander Motin X-Mailer: Apple Mail (2.1081) X-Mailman-Approved-At: Sat, 24 Jul 2010 18:32:43 +0000 Cc: freebsd-hackers@freebsd.org, freebsd-performance@freebsd.org Subject: Re: Intel TurboBoost in practice X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 Jul 2010 17:13:23 -0000 On 24 Jul 2010, at 14:53, Alexander Motin wrote: > Hi. >=20 > I've make small observations of Intel TurboBoost technology under > FreeBSD. This technology allows Intel Core i5/i7 CPUs to rise = frequency > of some cores if other cores are idle and power/thermal conditions > permit. CPU core counted as idle, if it has been put into C3 or deeper > power state (may reflect ACPI C2/C3 states). So to reach maximal > effectiveness, some tuning may be needed. >=20 > Here is my test case: FreeBSD 9-CURRENT on Core i5 650 CPU, 3.2GHz + = 1/2 > TurboBoost steps (+133/+266MHz) with boxed cooler at the open air. I = was > measuring building time of the net/mpd5 from sources, using only one = CPU > core (cpuset -l 0 time make). >=20 > Untuned system (hz=3D1000): 14.15 sec > Enabled ACPI C2 (hz=3D1000+C2): 13.85 sec > Enabled ACPI C3 (hz=3D1000+C3): 13.91 sec > Reduced HZ (hz=3D100): 14.16 sec > Enabled ACPI C2 (hz=3D100+C2): 13.85 sec > Enabled ACPI C3 (hz=3D100+C3): 13.86 sec > Timers tuned* (hz=3D100): 14.10 sec > Enabled ACPI C2 (hz=3D100+C2): 13.71 sec > Enabled ACPI C3 (hz=3D100+C3): 13.73 sec >=20 > All numbers tested few times and are repeatable up to +/-0.01sec. >=20 > *) Timers were tuned to reduce interrupt rates and respectively = increase > idle cores sleep time. These lines were added to loader.conf: > sysctl kern.eventtimer.timer1=3Di8254 > sysctl kern.eventtimer.timer2=3DNONE > kern.eventtimer.singlemul=3D1 > kern.hz=3D"100" >=20 > PS: In this case benefit is small, but it is the least that can be > achieved, depending on CPU model. Some models allow frequency to be > risen by up to 6 steps (+798MHz). The numbers that you are showing doesn't show much difference. Have you = tried buildworld? >=20 > PPS: I expect even better effect achieved by further reducing = interrupt > rates on idle CPUs. >=20 > --=20 > Alexander Motin > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to = "freebsd-hackers-unsubscribe@freebsd.org" >=20 > = __________________________________________________________________________= __________ > Use the link below to report this message as spam. > https://lavabit.com/apps/teacher?sig=3D1225540&key=3D3283483970 > = __________________________________________________________________________= __________ Regards, -- Rui Paulo