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 2BA466B004F for ; Tue, 7 Jul 2009 04:40:40 -0400 (EDT) Message-ID: <4A5314BF.5010607@redhat.com> Date: Tue, 07 Jul 2009 12:26:23 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [RFC][PATCH 0/4] ZERO PAGE again v2 References: <20090707165101.8c14b5ac.kamezawa.hiroyu@jp.fujitsu.com> <20090707084750.GX2714@wotan.suse.de> <4A530FD4.7060606@redhat.com> <20090707181829.10d48272.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090707181829.10d48272.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Nick Piggin , "linux-mm@kvack.org" , "hugh.dickins@tiscali.co.uk" , "akpm@linux-foundation.org" , torvalds@linux-foundation.org List-ID: On 07/07/2009 12:18 PM, KAMEZAWA Hiroyuki wrote: >> For kvm live migration, I've thought of extending mincore() to report if >> a page will be read as zeros. >> >> > BTW, ksm can scale enough to combine all pages which just includes zero ? > No heavy cache ping-pong without zero-page ? > ksm will increase cpu and cache load; it's oriented towards workloads where reducing memory pressure is more important than cpu load. For cpu-intensive, low sharing workloads it will be disabled. That's why I want an alternative way to deal with zero pages; it can be ZERO_PAGE, mincore(), or madvise(MADV_DROP_IFZERO). -- error compiling committee.c: too many arguments to function -- 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