Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263637AbUAITPs (ORCPT ); Fri, 9 Jan 2004 14:15:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263832AbUAITPs (ORCPT ); Fri, 9 Jan 2004 14:15:48 -0500 Received: from e35.co.us.ibm.com ([32.97.110.133]:29432 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S263637AbUAITPq (ORCPT ); Fri, 9 Jan 2004 14:15:46 -0500 Subject: Re: Strange IDE performance change in 2.6.1-rc1 (again) From: Ram Pai To: Andrew Morton Cc: ornati@lycos.it, gandalf@wlug.westbo.se, linux-kernel@vger.kernel.org In-Reply-To: <20040108171728.54a72cf7.akpm@osdl.org> References: <200401021658.41384.ornati@lycos.it> <200401071559.16130.ornati@lycos.it> <1073503421.10018.17.camel@dyn319250.beaverton.ibm.com> <200401072112.35334.ornati@lycos.it> <20040107155729.7e737c36.akpm@osdl.org> <1073610357.12720.20.camel@dyn319250.beaverton.ibm.com> <20040108171728.54a72cf7.akpm@osdl.org> Content-Type: text/plain Organization: Message-Id: <1073675705.14637.8.camel@dyn319250.beaverton.ibm.com> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.2.2 (1.2.2-5) Date: 09 Jan 2004 11:15:06 -0800 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 54 On Thu, 2004-01-08 at 17:17, Andrew Morton wrote: > Ram Pai wrote: > > > > Well this is my theory, somebody should validate it, > > One megabyte seems like far too litte memory to be triggering the effect > which you describe. But yes, the risk is certainly there. > > You could verify this with: > I cannot exactly reproduce what Pualo Ornati is seeing. Pualo: Request you to validate the following, 1) see whether you see a regression with files replacing the cat command in your script with dd if=big_file of=/dev/null bs=1M count=256 2) and if you do, check if you see a bunch of 'eek' with Andrew's following patch. (NOTE: without reverting the changes in filemap.c) -------------------------------------------------------------------------- --- 25/mm/filemap.c~a Thu Jan 8 17:15:57 2004 +++ 25-akpm/mm/filemap.c Thu Jan 8 17:16:06 2004 @@ -629,8 +629,10 @@ find_page: handle_ra_miss(mapping, ra, index); goto no_cached_page; } - if (!PageUptodate(page)) + if (!PageUptodate(page)) { + printk("eek!\n"); goto page_not_up_to_date; + } page_ok: /* If users can be writing to this page using arbitrary * virtual addresses, take care about potential aliasing --------------------------------------------------------------------------- Thanks, RP - 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/