From: Andi Kleen Subject: Re: High CPU Utilization When Copying to Ext4 Date: Fri, 08 Jul 2011 10:17:49 -0700 Message-ID: References: <341DAA96EE3A8444B6E4657BE8A846EA4B3DA126FE@NDJSSCC06.ndc.nasa.gov> <20110627030539.GF3064@thunk.org> <341DAA96EE3A8444B6E4657BE8A846EA4B3DA12708@NDJSSCC06.ndc.nasa.gov> <341DAA96EE3A8444B6E4657BE8A846EA4B3DA1270A@NDJSSCC06.ndc.nasa.gov> <50F503A1-6A16-41C4-9C27-0662063C7817@mit.edu> <4E0BBCE9.9020600@nasa.gov> <20110630023306.GY2729@thunk.org> <4E17398F.2090609@nasa.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Ted Ts'o" , "linux-ext4\@vger.kernel.org" To: Sean McCauliff Return-path: Received: from mga11.intel.com ([192.55.52.93]:56296 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752238Ab1GHRTW (ORCPT ); Fri, 8 Jul 2011 13:19:22 -0400 In-Reply-To: <4E17398F.2090609@nasa.gov> (Sean McCauliff's message of "Fri, 8 Jul 2011 10:08:31 -0700") Sender: linux-ext4-owner@vger.kernel.org List-ID: Sean McCauliff writes: > I tried running perf on the copy program on subset of the sparse > files. It seems like ext4 is the source of high cpu utilization. At > this point this high cpu utilization is very annoying, but I can live > with this problem. If you know something simple I could do to > alleviate this problem I would be most appreciative. At the end of > this email is a consolidation of information about this problem. > > Events: 6M cycles > -76.80% java [kernel.kallsyms] [k] ext4_mb_good_group > - ext4_mb_good_group Is your file system too full? A lot of file system get inefficient in allocating blocks when the file system is nearly full. -Andi -- ak@linux.intel.com -- Speaking for myself only