From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753866Ab2AWS5l (ORCPT ); Mon, 23 Jan 2012 13:57:41 -0500 Received: from mail-vx0-f174.google.com ([209.85.220.174]:48249 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753801Ab2AWS5k (ORCPT ); Mon, 23 Jan 2012 13:57:40 -0500 Message-ID: <4F1DADA0.4030300@vflare.org> Date: Mon, 23 Jan 2012 13:57:36 -0500 From: Nitin Gupta User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-Version: 1.0 To: Andrew Morton CC: Seth Jennings , Greg Kroah-Hartman , Dan Magenheimer , Brian King , Konrad Wilk , Dave Hansen , linux-mm@kvack.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/5] staging: zsmalloc: zsmalloc memory allocation library References: <1326149520-31720-1-git-send-email-sjenning@linux.vnet.ibm.com> <1326149520-31720-2-git-send-email-sjenning@linux.vnet.ibm.com> <20120120141232.a7572919.akpm@linux-foundation.org> In-Reply-To: <20120120141232.a7572919.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/20/2012 05:12 PM, Andrew Morton wrote: > On Mon, 9 Jan 2012 16:51:56 -0600 > Seth Jennings wrote: > >> This patch creates a new memory allocation library named >> zsmalloc. > > I haven't really begun to look at this yet. The code is using many > fields of struct page in new ways. This is key information for anyone > to effectively review the code. So please carefully document (within > the code itself) the ways in which the various page fields are used: > semantic meaning of the overload, relationships between them, any > locking rules or assumptions. Ditto any other data structures. This > code should be reviewed very carefully by others so please implement it > with that intention. > > It appears that a pile of dead code will be generated if CPU hotplug is > disabled. (That's if it compiles at all!). Please take a look at users > of hotcpu_notifier() - this facility cunningly causes all the hotplug code > to vanish from vmlinux if it is unneeded. > > ok, will look into these issues and add necessary documentation. > afacit this code should be added to core mm/. Addition of code like > this to core mm/ will be fiercely resisted on principle! Hence the > (currently missing) justifications for adding it had best be good ones. > I don't think this code should ever get into mm/ since its just a driver specific allocator. However its used by more than one driver (zcache and zram) so it may be moved to lib/ or drivers/zsmalloc atmost? Thanks, Nitin