From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f171.google.com (mail-pd0-f171.google.com [209.85.192.171]) by kanga.kvack.org (Postfix) with ESMTP id 39A306B0037 for ; Tue, 10 Dec 2013 21:16:49 -0500 (EST) Received: by mail-pd0-f171.google.com with SMTP id z10so8531551pdj.16 for ; Tue, 10 Dec 2013 18:16:48 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id sl10si12010833pab.128.2013.12.10.18.16.47 for ; Tue, 10 Dec 2013 18:16:47 -0800 (PST) Date: Tue, 10 Dec 2013 18:18:20 -0800 From: Greg Kroah-Hartman Subject: Re: [PATCH v9 0/4] zram/zsmalloc promotion Message-ID: <20131211021820.GA18540@kroah.com> References: <1386727479-18502-1-git-send-email-minchan@kernel.org> <20131211020959.GA17970@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131211020959.GA17970@bbox> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Jens Axboe , Hugh Dickins , Rik van Riel , Konrad Rzeszutek Wilk , Luigi Semenzato , Seth Jennings , Nitin Gupta , Bob Liu , Pekka Enberg , Mel Gorman On Wed, Dec 11, 2013 at 11:09:59AM +0900, Minchan Kim wrote: > Hello Greg, > > On Wed, Dec 11, 2013 at 11:04:35AM +0900, Minchan Kim wrote: > > Zram is a simple pseudo block device which can keep data on > > in-memory with compressed[1]. > > > > It have been used for many embedded system for several years > > One of significant usecase is in-memory swap device. > > Because NAND which is very popular on most embedded device > > is weak for frequent write without good wear-level > > and slow I/O hurts system's responsiblity so zram is really > > good choice to use memory efficiently. > > > > In previous trial, there was some argument[2] that zram has > > similar goal with zswap so let's merge zram's functionality > > into zswap via adding pseudo block device in zswap but I and > > some people(At least, Hugh and Rik) believe it's not a good idea. > > [2][3][4] and zswap might go writethrough model[5]. It makes > > clear difference zram and zswap. > > > > Zram itself is simple/well-designed/good abstraciton so it has > > clear market(ex, Android, TV, ChromeOS, some Linux distro) which > > is never niche. :) > > > > Another zram-blk's usecase is following as. > > The admin can use it as tmpfs so it could help small memory system. > > The tmpfs is never good solution for swapless embedded system. > > > > Patch 1 adds new Kconfig for zram to use page table method instead > > of copy. > > > > Patch 2 adds more comment for zsmalloc. > > > > Patch 3 moves zsmalloc under mm. > > > > Patch 4 moves zram from driver/staging to driver/blocks, finally. > > Patch 1(suggested by Andrew Morton) and 2(Just comment to make review easy) > are prepartion for promotion so I hope it could be merged into your staging > regardless of allowing promotion at the moment. Sure, I'll be glad to do so, thanks for letting me know. greg k-h -- 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