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 ESMTP id 207016B022C for ; Sun, 2 May 2010 17:06:37 -0400 (EDT) MIME-Version: 1.0 Message-ID: Date: Sun, 2 May 2010 14:05:59 -0700 (PDT) From: Dan Magenheimer Subject: RE: Frontswap [PATCH 0/4] (was Transcendent Memory): overview References: <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> <4BDB026E.1030605@redhat.com> <4BDB18CE.2090608@goop.org4BDB2069.4000507@redhat.com> <3a62a058-7976-48d7-acd2-8c6a8312f10f@default20100502071059.GF1790@ucw.cz> <47d6b5d9-beb5-4e49-9910-064d6f7b13e5@default 20100502200615.GA9051@elf.ucw.cz> In-Reply-To: <20100502200615.GA9051@elf.ucw.cz> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Pavel Machek Cc: Avi Kivity , Jeremy Fitzhardinge , Dave Hansen , linux-kernel@vger.kernel.org, linux-mm@kvack.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 List-ID: > From: Pavel Machek [mailto:pavel@ucw.cz] >=20 > > > So what needs to be said here is 'frontswap is XX times faster than > > > swap_ops based solution on workload YY'. > > > > Are you asking me to demonstrate that swap-to-hypervisor-RAM is > > faster than swap-to-disk? >=20 > I would like comparison of swap-to-frontswap vs. swap-to-RAMdisk. > =09=09=09=09=09=09=09=09=09Pavel Well, it's not really apples-to-apples because swap-to-RAMdisk is copying to a chunk of RAM with a known permanently-fixed size so it SHOULD be faster than swap-to-hypervisor, and should *definitely* be faster than swap-to-in-kernel-compressed-RAM but I suppose it is still an interesting comparison. I'll see what I can do, but it will probably be a couple days to figure out how to measure it (e.g. without accidentally measuring any swap-to-disk). -- 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