From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 040046B004D for ; Mon, 8 Jun 2009 10:37:34 -0400 (EDT) Received: from localhost (smtp.ultrahosting.com [127.0.0.1]) by smtp.ultrahosting.com (Postfix) with ESMTP id E2C8F82C4DD for ; Mon, 8 Jun 2009 12:14:09 -0400 (EDT) Received: from smtp.ultrahosting.com ([74.213.175.254]) by localhost (smtp.ultrahosting.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id G1SJdw4KYgSR for ; Mon, 8 Jun 2009 12:14:05 -0400 (EDT) Received: from gentwo.org (unknown [74.213.171.31]) by smtp.ultrahosting.com (Postfix) with ESMTP id 73FA382C4DB for ; Mon, 8 Jun 2009 12:14:02 -0400 (EDT) Date: Mon, 8 Jun 2009 11:34:06 -0400 (EDT) From: Christoph Lameter Subject: Re: [PATCH 2/3] vmscan: make mapped executable pages the first class citizen In-Reply-To: <20090608091201.953724007@intel.com> Message-ID: References: <20090608091044.880249722@intel.com> <20090608091201.953724007@intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Wu Fengguang Cc: Andrew Morton , KOSAKI Motohiro , Elladan , Nick Piggin , Andi Kleen , Rik van Riel , Peter Zijlstra , Johannes Weiner , "tytso@mit.edu" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" List-ID: On Mon, 8 Jun 2009, Wu Fengguang wrote: > 1.2) test scenario > > - nfsroot gnome desktop with 512M physical memory > - run some programs, and switch between the existing windows > after starting each new program. Is there a predefined sequence or does this vary between tests? Scripted? What percentage of time is saved in the test after due to the modifications? Around 20%? > (1) begin: shortly after the big read IO starts; > (2) end: just before the big read IO stops; > (3) restore: the big read IO stops and the zsh working set restored > (4) restore X: after IO, switch back and forth between the urxvt and firefox > windows to restore their working set. Any action done on the firefox sessions? Or just switch to a firefox session that needs to redraw? > The above console numbers show that > > - The startup pgmajfault of 2.6.30-rc4-mm is merely 1/3 that of 2.6.29. > I'd attribute that improvement to the mmap readahead improvements :-) So there are other effects,,, You not measuring the effect only this patchset? > - The pgmajfault increment during the file copy is 633-630=3 vs 260-210=50. > That's a huge improvement - which means with the VM_EXEC protection logic, > active mmap pages is pretty safe even under partially cache hot streaming IO. Looks good. > - The absolute nr_mapped drops considerably to 1/9 during the big IO, and the > dropped pages are mostly inactive ones. The patch has almost no impact in > this aspect, that means it won't unnecessarily increase memory pressure. > (In contrast, your 20% mmap protection ratio will keep them all, and > therefore eliminate the extra 41 major faults to restore working set > of zsh etc.) Good. -- 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/ . Don't email: email@kvack.org