From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id DBBAA6B023F for ; Fri, 30 Apr 2010 12:08:13 -0400 (EDT) Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by e6.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id o3UG5tTR011170 for ; Fri, 30 Apr 2010 12:05:55 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o3UG85Nn163694 for ; Fri, 30 Apr 2010 12:08:05 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o3UG84HT002547 for ; Fri, 30 Apr 2010 13:08:05 -0300 Subject: RE: Frontswap [PATCH 0/4] (was Transcendent Memory): overview From: Dave Hansen In-Reply-To: <084f72bf-21fd-4721-8844-9d10cccef316@default> References: <4BD16D09.2030803@redhat.com> > > <4BD1A74A.2050003@redhat.com> > <4830bd20-77b7-46c8-994b-8b4fa9a79d27@default> > <4BD1B427.9010905@redhat.com> <4BD1B626.7020702@redhat.com> > <5fa93086-b0d7-4603-bdeb-1d6bfca0cd08@default> > <4BD3377E.6010303@redhat.com> > <1c02a94a-a6aa-4cbb-a2e6-9d4647760e91@default4BD43033.7090706@redhat.com> > > <20100428055538.GA1730@ucw.cz> <1272591924.23895.807.camel@nimitz 4BDA8324.7090409@redhat.com> <084f72bf-21fd-4721-8844-9d10cccef316@default> Content-Type: text/plain Date: Fri, 30 Apr 2010 09:08:00 -0700 Message-Id: <1272643680.23895.2537.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Dan Magenheimer Cc: Avi Kivity , Pavel Machek , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jeremy@goop.org, hugh.dickins@tiscali.co.uk, ngupta@vflare.org, JBeulich@novell.com, chris.mason@oracle.com, kurt.hackel@oracle.com, dave.mccracken@oracle.com, npiggin@suse.de, akpm@linux-foundation.org, riel@redhat.com, Martin Schwidefsky List-ID: On Fri, 2010-04-30 at 08:59 -0700, Dan Magenheimer wrote: > Dave or others can correct me if I am wrong, but I think CMM2 also > handles dirty pages that must be retained by the hypervisor. The > difference between CMM2 (for dirty pages) and frontswap is that > CMM2 sets hints that can be handled asynchronously while frontswap > provides explicit hooks that synchronously succeed/fail. Once pages were dirtied (or I guess just slightly before), they became volatile, and I don't think the hypervisor could do anything with them. It could still swap them out like usual, but none of the CMM-specific optimizations could be performed. CC'ing Martin since he's the expert. :) -- Dave -- 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