From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755904Ab3BDO5d (ORCPT ); Mon, 4 Feb 2013 09:57:33 -0500 Received: from e8.ny.us.ibm.com ([32.97.182.138]:59855 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754917Ab3BDO5b (ORCPT ); Mon, 4 Feb 2013 09:57:31 -0500 Message-ID: <510FCC12.1060604@linux.vnet.ibm.com> Date: Mon, 04 Feb 2013 08:56:18 -0600 From: Seth Jennings User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Simon Jeons CC: Andrew Morton , Greg Kroah-Hartman , Nitin Gupta , Minchan Kim , Konrad Rzeszutek Wilk , Dan Magenheimer , Robert Jennings , Jenifer Hopper , Mel Gorman , Johannes Weiner , Rik van Riel , Larry Woodman , Benjamin Herrenschmidt , Dave Hansen , linux-mm@kvack.org, linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org Subject: Re: [PATCHv4 0/7] zswap: compressed swap caching References: <1359495627-30285-1-git-send-email-sjenning@linux.vnet.ibm.com> <1359682784.3574.2.camel@kernel> <510BDB8F.5000104@linux.vnet.ibm.com> <1359850629.3064.1.camel@kernel.cn.ibm.com> In-Reply-To: <1359850629.3064.1.camel@kernel.cn.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13020414-9360-0000-0000-00001019F94C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/02/2013 06:17 PM, Simon Jeons wrote: > On Fri, 2013-02-01 at 09:13 -0600, Seth Jennings wrote: >> On 01/31/2013 07:39 PM, Simon Jeons wrote: >>> Hi Seth, >>> On Tue, 2013-01-29 at 15:40 -0600, Seth Jennings wrote: >> >>>> Performance, Kernel Building: >>>> >>>> Setup >>>> ======== >>>> Gentoo w/ kernel v3.7-rc7 >>>> Quad-core i5-2500 @ 3.3GHz >>>> 512MB DDR3 1600MHz (limited with mem=512m on boot) >>>> Filesystem and swap on 80GB HDD (about 58MB/s with hdparm -t) >>>> majflt are major page faults reported by the time command >>>> pswpin/out is the delta of pswpin/out from /proc/vmstat before and after >>>> then make -jN >>>> >>>> Summary >>>> ======== >>>> * Zswap reduces I/O and improves performance at all swap pressure levels. >>>> >>>> * Under heavy swaping at 24 threads, zswap reduced I/O by 76%, saving >>>> over 1.5GB of I/O, and cut runtime in half. >>> >>> How to get your benchmark? >> >> It's just kernel building. So "make" :) >> >> I intentionally choose this workload so people wouldn't have to jump >> through hoops to replicate the results. > > Thanks for your clarify. zswap is belong to in-kernel compression, > correct? then what's the difference between in-memory compression and > in-kernel compression? Dan made this distinction (possibly unintentionally) in his email. For me "in-kernel" means "done by the kernel" and "in-memory" means "stored in RAM". So it is compression of RAM pages done by the kernel and stored back in RAM. I sum up the functionality of zswap as "compressed swap caching", which I think better conveys what zswap does exactly. Seth