Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752791Ab2KSBUJ (ORCPT ); Sun, 18 Nov 2012 20:20:09 -0500 Received: from LGEMRELSE1Q.lge.com ([156.147.1.111]:60575 "EHLO LGEMRELSE1Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752722Ab2KSBUH (ORCPT ); Sun, 18 Nov 2012 20:20:07 -0500 X-AuditID: 9c93016f-b7b42ae000004383-16-50a98943e425 Date: Mon, 19 Nov 2012 10:27:29 +0900 From: Minchan Kim To: Andrew Morton Cc: Greg KH , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dan Magenheimer , Nitin Gupta , Seth Jennings , Konrad Rzeszutek Wilk , Jens Axboe , Pekka Enberg , gaowanlong@cn.fujitsu.com Subject: Re: [PATCH v4 0/3] zram/zsmalloc promotion Message-ID: <20121119012729.GA7747@bbox> References: <1351840367-4152-1-git-send-email-minchan@kernel.org> <20121106153213.03e9cc9f.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2096 Lines: 54 Andrew? On Wed, Nov 07, 2012 at 07:38:04PM +0900, Minchan Kim wrote: > Hi Andrew, > > On Wed, Nov 7, 2012 at 8:32 AM, Andrew Morton > wrote: > > On Fri, 2 Nov 2012 16:12:44 +0900 > > Minchan Kim wrote: > > > >> This patchset promotes zram/zsmalloc from staging. > > > > The changelogs are distressingly short of *reasons* for doing this! > > > >> Both are very clean and zram have been used by many embedded product > >> for a long time. > > > > Well that's interesting. > > > > Which embedded products? How are they using zram and what benefit are > > they observing from it, in what scenarios? > > > > At least, major TV companys have used zram as swap since two years ago and > recently our production team released android smart phone with zram which > is used as swap, too. > And there is trial to use zram as swap in ChromeOS project, too. (Although > they report some problem recently, it was not a problem of zram). > When you google zram, you can find various usecase in xda-developers. > > With my experience, the benefit in real practice was to remove jitter of > video application. It would be effect of efficient memory usage by > compression but more issue is whether swap is there or not in the system. > As you know, recent mobile platform have used JAVA so there are lots of > anonymous pages. But embedded system normally doesn't use eMMC or SDCard as > swap because there is wear-leveling issue and latency so we can't reclaim > anymous pages. It sometime ends up making system very slow when it requires > to get contiguous memory and even many file-backed pages are evicted. It's > never what embedded people want it. Zram is one of best solution for that. > > It's very hard to type with mobile phone. :( > > -- > Kind regards, > Minchan Kim -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/