From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161243AbWJPJDE (ORCPT ); Mon, 16 Oct 2006 05:03:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161244AbWJPJDE (ORCPT ); Mon, 16 Oct 2006 05:03:04 -0400 Received: from mail.gmx.de ([213.165.64.20]:45724 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1161243AbWJPJDC (ORCPT ); Mon, 16 Oct 2006 05:03:02 -0400 X-Authenticated: #14349625 Subject: Re: Major slab mem leak with 2.6.17 / GCC 4.1.1 From: Mike Galbraith To: Catalin Marinas Cc: Pekka Enberg , "nmeyers@vestmark.com" , linux-kernel@vger.kernel.org In-Reply-To: References: <20061013004918.GA8551@viviport.com> <84144f020610122256p7f615f93lc6d8dcce7be39284@mail.gmail.com> <1160899154.5935.19.camel@Homer.simpson.net> <1160976752.6477.3.camel@Homer.simpson.net> <1160989710.17131.14.camel@Homer.simpson.net> Content-Type: text/plain Date: Mon, 16 Oct 2006 09:33:35 +0000 Message-Id: <1160991215.17131.26.camel@Homer.simpson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.6.0 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2006-10-16 at 09:44 +0100, Catalin Marinas wrote: > On 16/10/06, Mike Galbraith wrote: > > On Mon, 2006-10-16 at 09:07 +0100, Catalin Marinas wrote: > > > Kmemleak introduces some overhead but shouldn't be that bad. > > > DEBUG_SLAB also introduces an overhead by erasing the data in the > > > allocated blocks. > > > > 2.6.18 with your rc6 patch booted normally with stack unwind enabled. > > The only difference is that kmemleak now uses save_stack_trace() to > generate the call chain. In the previous versions I implemented a > simple stack backtrace myself, with the disadvantage that it only > worked on ARM and x86. > > I think kmemleak should use the common stack trace API and investigate > why it is slower (either save_stack_trace is slower with stack unwind > enabled or kmemleak doesn't use these functions properly). The stack traces look fine without unwind, and at a glance looked fine with unwind as well, so I speculate you must be using save_stack_trace properly. The only difference I noticed was the incredible speed difference. I gave up on getting to run level 5 with unwind, getting to level 2 took ages, and the box was horribly slow at everything. -Mike