From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx118.postini.com [74.125.245.118]) by kanga.kvack.org (Postfix) with SMTP id C247B6B0002 for ; Thu, 31 Jan 2013 15:16:38 -0500 (EST) Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 31 Jan 2013 15:16:26 -0500 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 2C8B46E8805 for ; Thu, 31 Jan 2013 15:08:05 -0500 (EST) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r0VK86qL312338 for ; Thu, 31 Jan 2013 15:08:06 -0500 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r0VK85fE016907 for ; Thu, 31 Jan 2013 18:08:06 -0200 Date: Thu, 31 Jan 2013 14:07:31 -0600 From: Robert Jennings Subject: Re: [PATCHv4 3/7] zswap: add to mm/ Message-ID: <20130131200731.GA11067@linux.vnet.ibm.com> References: <1359495627-30285-1-git-send-email-sjenning@linux.vnet.ibm.com> <1359495627-30285-4-git-send-email-sjenning@linux.vnet.ibm.com> <20130131070716.GF23548@blaptop> <510AC0C6.4020705@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <510AC0C6.4020705@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Seth Jennings Cc: Minchan Kim , Andrew Morton , Greg Kroah-Hartman , Nitin Gupta , Konrad Rzeszutek Wilk , Dan Magenheimer , 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 * Seth Jennings (sjenning@linux.vnet.ibm.com) wrote: > On 01/31/2013 01:07 AM, Minchan Kim wrote: > > On Tue, Jan 29, 2013 at 03:40:23PM -0600, Seth Jennings wrote: > >> zswap is a thin compression backend for frontswap. It receives > >> pages from frontswap and attempts to store them in a compressed > >> memory pool, resulting in an effective partial memory reclaim and > >> dramatically reduced swap device I/O. > >> > >> Additionally, in most cases, pages can be retrieved from this > >> compressed store much more quickly than reading from tradition > >> swap devices resulting in faster performance for many workloads. > >> > >> This patch adds the zswap driver to mm/ > >> > >> Signed-off-by: Seth Jennings > >> --- > >> mm/Kconfig | 15 ++ > >> mm/Makefile | 1 + > >> mm/zswap.c | 656 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> 3 files changed, 672 insertions(+) > >> create mode 100644 mm/zswap.c > >> > >> diff --git a/mm/Kconfig b/mm/Kconfig > >> index 278e3ab..14b9acb 100644 > >> --- a/mm/Kconfig > >> +++ b/mm/Kconfig > >> @@ -446,3 +446,18 @@ config FRONTSWAP > >> and swap data is stored as normal on the matching swap device. > >> > >> If unsure, say Y to enable frontswap. > >> + > >> +config ZSWAP > >> + bool "In-kernel swap page compression" > >> + depends on FRONTSWAP && CRYPTO > >> + select CRYPTO_LZO > >> + select ZSMALLOC > > > > Again, I'm asking why zswap should have a dependent on CRPYTO? > > Couldn't we support it as a option? I'd like to use zswap without CRYPTO > > like zram. > > The reason we need CRYPTO is that zswap uses it to support a pluggable > compression model. zswap can use any compressor that has a crypto API > driver. zswap has _symbol dependencies_ on CRYPTO. If it isn't > selected, the build breaks. And we went with a pluggable model so that we could support hardware accelerated compression engines like: 0e16aaf powerpc/crypto: add 842 hardware compression driver --Rob Jennings -- 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