From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 25 Jun 2001 17:16:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 25 Jun 2001 17:15:43 -0400 Received: from m52-mp1-cvx1a.col.ntl.com ([213.104.68.52]:21632 "EHLO [213.104.68.52]") by vger.kernel.org with ESMTP id ; Mon, 25 Jun 2001 17:15:41 -0400 To: Rik van Riel Cc: , Subject: Re: VM tuning through fault trace gathering [with actual code] In-Reply-To: From: John Fremlin Date: 25 Jun 2001 22:15:31 +0100 In-Reply-To: (Rik van Riel's message of "Mon, 25 Jun 2001 14:57:39 -0300 (BRST)") Message-ID: User-Agent: Gnus/5.090004 (Oort Gnus v0.04) XEmacs/21.1 (GTK) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Rik van Riel writes: > On 25 Jun 2001, John Fremlin wrote: > > > Last year I had the idea of tracing the memory accesses of the > > system to improve the VM - the traces could be used to test > > algorithms in userspace. The difficulty is of course making all > > memory accesses fault without destroying system performance. > > Sounds like a cool idea. One thing you should keep in mind though > is to gather traces of the WHOLE SYSTEM and not of individual > applications. In the current patch all pagefaults are recorded from all sources. I'd like to be able to catch read(2) and write(2) (buffer cache stuff) as well but I don't know how . . . . > There has to be a way to balance the eviction of pages from > applications against those of other applications. Of course! It is important not to regard each thread group as an independent entity IMHO (had a big old argument about this). [...] -- http://ape.n3.net From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: VM tuning through fault trace gathering [with actual code] References: From: John Fremlin Date: 25 Jun 2001 22:15:31 +0100 In-Reply-To: (Rik van Riel's message of "Mon, 25 Jun 2001 14:57:39 -0300 (BRST)") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Rik van Riel writes: > On 25 Jun 2001, John Fremlin wrote: > > > Last year I had the idea of tracing the memory accesses of the > > system to improve the VM - the traces could be used to test > > algorithms in userspace. The difficulty is of course making all > > memory accesses fault without destroying system performance. > > Sounds like a cool idea. One thing you should keep in mind though > is to gather traces of the WHOLE SYSTEM and not of individual > applications. In the current patch all pagefaults are recorded from all sources. I'd like to be able to catch read(2) and write(2) (buffer cache stuff) as well but I don't know how . . . . > There has to be a way to balance the eviction of pages from > applications against those of other applications. Of course! It is important not to regard each thread group as an independent entity IMHO (had a big old argument about this). [...] -- http://ape.n3.net -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/