Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759553AbZD2QHh (ORCPT ); Wed, 29 Apr 2009 12:07:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758996AbZD2QHN (ORCPT ); Wed, 29 Apr 2009 12:07:13 -0400 Received: from mga11.intel.com ([192.55.52.93]:17360 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759415AbZD2QHL (ORCPT ); Wed, 29 Apr 2009 12:07:11 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.40,266,1239001200"; d="scan'208";a="452609305" From: "Wilcox, Matthew R" To: "Styner, Douglas W" , Andi Kleen , Andrew Morton CC: "linux-kernel@vger.kernel.org" , "Tripathi, Sharad C" , "arjan@linux.intel.com" , "Kleen, Andi" , "Siddha, Suresh B" , "Ma, Chinang" , "Wang, Peter Xihong" , "Nueckel, Hubert" , "Recalde, Luis F" , "Nelson, Doug" , "Cheng, Wu-sun" , "Prickett, Terry O" , "Shunmuganathan, Rajalakshmi" , "Garg, Anil K" , "Chilukuri, Harita" , "chris.mason@oracle.com" Date: Wed, 29 Apr 2009 10:06:44 -0600 Subject: RE: Mainline kernel OLTP performance update Thread-Topic: Mainline kernel OLTP performance update Thread-Index: AcnIpH2wYNuL0nVjSjitaku5DQLCvgAPXCLwAACgmSA= Message-ID: References: <20090429002930.b786348b.akpm@linux-foundation.org> <871vrbrhhy.fsf@basil.nowhere.org> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by alpha.home.local id n3TG8Fqu015804 Content-Length: 2327 Lines: 51 Is it possible that's simply 'oprofile has a 4% overhead'? > -----Original Message----- > From: Styner, Douglas W > Sent: Wednesday, April 29, 2009 9:00 AM > To: Andi Kleen; Andrew Morton > Cc: linux-kernel@vger.kernel.org; Tripathi, Sharad C; > arjan@linux.intel.com; Wilcox, Matthew R; Kleen, Andi; Siddha, Suresh B; > Ma, Chinang; Wang, Peter Xihong; Nueckel, Hubert; Recalde, Luis F; Nelson, > Doug; Cheng, Wu-sun; Prickett, Terry O; Shunmuganathan, Rajalakshmi; Garg, > Anil K; Chilukuri, Harita; chris.mason@oracle.com > Subject: RE: Mainline kernel OLTP performance update > > What we showed was that vmstat and vtune agreed wrt system/user time. > Oprofile is off by ~4% (4% too low for user. 4% too high for system) > > >-----Original Message----- > >From: Andi Kleen [mailto:andi@firstfloor.org] > >Sent: Wednesday, April 29, 2009 1:28 AM > >To: Andrew Morton > >Cc: Styner, Douglas W; linux-kernel@vger.kernel.org; Tripathi, Sharad C; > >arjan@linux.intel.com; Wilcox, Matthew R; Kleen, Andi; Siddha, Suresh B; > >Ma, Chinang; Wang, Peter Xihong; Nueckel, Hubert; Recalde, Luis F; > Nelson, > >Doug; Cheng, Wu-sun; Prickett, Terry O; Shunmuganathan, Rajalakshmi; > Garg, > >Anil K; Chilukuri, Harita; chris.mason@oracle.com > >Subject: Re: Mainline kernel OLTP performance update > > > >Andrew Morton writes: > > > >>> ======oprofile CPU_CLK_UNHALTED for top 30 functions > >>> Cycles% 2.6.24.2 Cycles% 2.6.30-rc3 > >>> 74.8578 69.1925 > >> > >> ouch, that's a large drop in userspace CPU occupancy. It seems > >> inconsistent with the 1.91% above. > > > >That was determined to be an oprofile artifact/regression (see Doug's > >other email+thread) The 2.6.30 oprofile seems to be less accurate than > >the one in 2.6.24. Of course the question is if it can't get > >the user space right, is the kernel data accurate. But I believe > >Doug verified with vtune that the kernel data is roughly correct, > >just user space profiling was slightly bogus (right, Doug, or > >do I misrepresent that?) > > > >-Andi > > > >-- > >ak@linux.intel.com -- Speaking for myself only. ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?