From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 611756B004F for ; Mon, 13 Jul 2009 02:25:40 -0400 (EDT) Date: Mon, 13 Jul 2009 08:46:41 +0200 From: Nick Piggin Subject: Re: [RFC][PATCH 0/4] ZERO PAGE again v2 Message-ID: <20090713064641.GL14666@wotan.suse.de> References: <20090707165101.8c14b5ac.kamezawa.hiroyu@jp.fujitsu.com> <20090707084750.GX2714@wotan.suse.de> <20090707180629.cd3ac4b6.kamezawa.hiroyu@jp.fujitsu.com> <20090708173206.GN356@random.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Andrea Arcangeli , KAMEZAWA Hiroyuki , "linux-mm@kvack.org" , avi@redhat.com, akpm@linux-foundation.org, torvalds@linux-foundation.org List-ID: On Fri, Jul 10, 2009 at 12:18:07PM +0100, Hugh Dickins wrote: > On Wed, 8 Jul 2009, Andrea Arcangeli wrote: > > On Tue, Jul 07, 2009 at 06:06:29PM +0900, KAMEZAWA Hiroyuki wrote: > > harmful as there's a double page fault generated instead of a single > > one, kksmd has a cost but zeropage isn't free either in term of page > > faults too) > > Much as I like KSM, I have to agree with Avi, that if people are > wanting the ZERO_PAGE back in compute-intensive loads, then relying I can't imagine ZERO_PAGE would be too widely used in compute-intensive loads. At least, not serious stuff. Nobody wants to spend 4K of cache and one TLB entry for one or two non-zero floating point numbers in a big sparse matrix. Not to mention the cache and memory overhead of just scanning through lots of zeros. -- 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