From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753008Ab0INIKp (ORCPT ); Tue, 14 Sep 2010 04:10:45 -0400 Received: from mail-ew0-f46.google.com ([209.85.215.46]:34090 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752387Ab0INIKk (ORCPT ); Tue, 14 Sep 2010 04:10:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:user-agent:cc:references:in-reply-to :mime-version:content-type:content-transfer-encoding:message-id; b=SpD+kOCsVXlARxBz2DwHjz4usI7OzYyFT1/YE97QA9XQxxsDthfLWcxZtO6qmscaR9 knFCHTiXtqcdhYKjbWMYm/WcHzOhk6a+NPZs1k4ChFsgnNbL804yO/u9BzoZqlzP2gK9 oWlUR0LwurEp80iF7KPB18L+nV+Juh/VrbvcM= From: Vasily Khoruzhick To: Venkatesh Pallipadi Subject: Re: Interrupt latency on some 945GM platforms Date: Tue, 14 Sep 2010 11:09:36 +0300 User-Agent: KMail/1.13.5 (Linux/2.6.35-gentoo-r5-anarsoul; KDE/4.5.1; i686; ; ) Cc: Jesse Barnes , intel-gfx@lists.freedesktop.org, Thomas Gleixner , linux-kernel@vger.kernel.org References: <201009132336.17310.anarsoul@gmail.com> <201009140104.03135.anarsoul@gmail.com> In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart18620413.uCaTN5nVUu"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <201009141109.41596.anarsoul@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --nextPart18620413.uCaTN5nVUu Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1=82 = 14 of September 2010 03:55:32 =D0=B0=D0=B2=D1=82=D0=BE=D1=80 Venkatesh Pall= ipadi=20 =D0=BD=D0=B0=D0=BF=D0=B8=D1=81=D0=B0=D0=BB: > Whats the clockevent in this case ("Tick Device" section of > /proc/timer_list). clocksource=3D option only changes the clocksource used > to maintain > timeofday. But, timer interrupt (clockevent) source will not change. > Wondering how just the clocksource change is making the diff here.. >=20 > Also, if clocksource tsc has a higher rating than HPET. The reason > HPET is getting used as clocksource in the first place seems to be due > to TSC is not a dependable clocksource on this platform (may be it > stops in C3). So, I am not sure forcing it to tsc will be a good > thing. May be clocksource=3Dacpi_pm is a better thing to try. >=20 > Thanks, > Venki I investigated it a bit and found out that single nohz=3Doff option helps. = Just=20 changing clocksource doesn't help, but it works smoothly with any clocksour= ce=20 with nohz=3Doff. So, it seems that something wrong with intel driver while= =20 system is in tickless mode.=20 Regards Vasily --nextPart18620413.uCaTN5nVUu Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) iEYEABECAAYFAkyPLcUACgkQRM6pQpltKE7B1gCfTr8l8V7ZHlxVy/yvVeIbq4Rw 0ZcAoLn83BiqtHbUBQy5hkRpr1ZfGedh =0Rlc -----END PGP SIGNATURE----- --nextPart18620413.uCaTN5nVUu--