Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752966AbYCMHtT (ORCPT ); Thu, 13 Mar 2008 03:49:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751480AbYCMHtG (ORCPT ); Thu, 13 Mar 2008 03:49:06 -0400 Received: from mga10.intel.com ([192.55.52.92]:32957 "EHLO fmsmga102.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751372AbYCMHtF (ORCPT ); Thu, 13 Mar 2008 03:49:05 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.25,493,1199692800"; d="scan'208";a="305832323" Subject: hackbench regression since 2.6.25-rc From: "Zhang, Yanmin" To: Kay Sievers , Greg Kroah-Hartman Cc: LKML Content-Type: text/plain; charset=utf-8 Date: Thu, 13 Mar 2008 15:46:57 +0800 Message-Id: <1205394417.3215.85.camel@ymzhang> Mime-Version: 1.0 X-Mailer: Evolution 2.9.2 (2.9.2-2.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1077 Lines: 28 Comparing with 2.6.24, on my 16-core tigerton, hackbench process mode has about 40% regression with 2.6.25-rc1, and more than 20% regression with kernel 2.6.25-rc4, because rc4 includes the reverting patch of scheduler load balance. Command to start it. #hackbench 100 process 2000 I ran it for 3 times and sum the values. I tried to investiagte it by bisect. Kernel up to tag 0f4dafc0563c6c49e17fe14b3f5f356e4c4b8806 has the 20% regression. Kernel up to tag 6e90aa972dda8ef86155eefcdbdc8d34165b9f39 hasn't regression. Any bisect between above 2 tags cause kernel hang. I tried to checkout to a point between these 2 tags for many times manually and kernel always paniced. All patches between the 2 tags are on kobject restructure. I guess such restructure creates more cache miss on the 16-core tigerton. Any idea? -yanmin -- 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/