From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262154AbVF1AdL (ORCPT ); Mon, 27 Jun 2005 20:33:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262153AbVF1AdL (ORCPT ); Mon, 27 Jun 2005 20:33:11 -0400 Received: from smtp201.mail.sc5.yahoo.com ([216.136.129.91]:25523 "HELO smtp201.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S262154AbVF1AdF (ORCPT ); Mon, 27 Jun 2005 20:33:05 -0400 Message-ID: <42C09AB3.7030907@yahoo.com.au> Date: Tue, 28 Jun 2005 10:32:51 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050324 Debian/1.7.6-1 X-Accept-Language: en MIME-Version: 1.0 To: Benjamin LaHaise CC: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [rfc] lockless pagecache References: <42BF9CD1.2030102@yahoo.com.au> <20050627004624.53f0415e.akpm@osdl.org> <42BFB287.5060104@yahoo.com.au> <20050627131710.GC13945@kvack.org> In-Reply-To: <20050627131710.GC13945@kvack.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Benjamin LaHaise wrote: > On Mon, Jun 27, 2005 at 06:02:15PM +1000, Nick Piggin wrote: > >>However I think for Oracle and others that use shared memory like >>this, they are probably not doing linear access, so that would be a >>net loss. I'm not completely sure (I don't have access to real loads >>at the moment), but I would have thought those guys would have looked >>into fault ahead if it were a possibility. > > > Shared memory overhead doesn't show up on any of the database benchmarks > I've seen, as they tend to use huge pages that are locked in memory, and > thus don't tend to access the page cache at all after ramp up. > To be quite honest I don't have any real workloads here that stress it, however I was told that it is a problem for oracle database. If there is anyone else who has problems then I'd be interested to hear them as well. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com