From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx186.postini.com [74.125.245.186]) by kanga.kvack.org (Postfix) with SMTP id B16C56B0005 for ; Thu, 11 Apr 2013 13:53:29 -0400 (EDT) MIME-Version: 1.0 Message-ID: <3b7f1680-0cf7-46f0-b468-04068a1256d8@default> Date: Thu, 11 Apr 2013 10:53:10 -0700 (PDT) From: Dan Magenheimer Subject: RE: zsmalloc defrag (Was: [PATCH] mm: remove compressed copy from zram in-memory) References: <1365400862-9041-1-git-send-email-minchan@kernel.org> <20130409012719.GB3467@blaptop> <20130409013606.GC3467@blaptop> <3cc0fdea-7064-4b95-bbee-30c6448f0487@default> <20130410005449.GG6836@blaptop> In-Reply-To: <20130410005449.GG6836@blaptop> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hugh Dickins , Seth Jennings , Nitin Gupta , Konrad Rzeszutek Wilk , Shaohua Li , Bob Liu , Shuah Khan > From: Minchan Kim [mailto:minchan@kernel.org] > Subject: Re: zsmalloc defrag (Was: [PATCH] mm: remove compressed copy fro= m zram in-memory) >=20 > On Tue, Apr 09, 2013 at 01:37:47PM -0700, Dan Magenheimer wrote: > > > From: Minchan Kim [mailto:minchan@kernel.org] > > > Subject: Re: zsmalloc defrag (Was: [PATCH] mm: remove compressed copy= from zram in-memory) > > > > > > On Tue, Apr 09, 2013 at 10:27:19AM +0900, Minchan Kim wrote: > > > > Hi Dan, > > > > > > > > On Mon, Apr 08, 2013 at 09:32:38AM -0700, Dan Magenheimer wrote: > > > > > > From: Minchan Kim [mailto:minchan@kernel.org] > > > > > > Sent: Monday, April 08, 2013 12:01 AM > > > > > > Subject: [PATCH] mm: remove compressed copy from zram in-memory > > > > > > > > > > (patch removed) > > > > > > > > > > > Fragment ratio is almost same but memory consumption and compil= e time > > > > > > is better. I am working to add defragment function of zsmalloc. > > > > > > > > > > Hi Minchan -- > > > > > > > > > > I would be very interested in your design thoughts on > > > > > how you plan to add defragmentation for zsmalloc. In > > > > > > > > What I can say now about is only just a word "Compaction". > > > > As you know, zsmalloc has a transparent handle so we can do whateve= r > > > > under user. Of course, there is a tradeoff between performance > > > > and memory efficiency. I'm biased to latter for embedded usecase. > > > > > > > > And I might post it because as you know well, zsmalloc > > > > > > Incomplete sentense, > > > > > > I might not post it until promoting zsmalloc because as you know well= , > > > zsmalloc/zram's all new stuffs are blocked into staging tree. > > > Even if we could add it into staging, as you know well, staging is wh= ere > > > every mm guys ignore so we end up needing another round to promote it= . sigh. > > > > > > I hope it gets better after LSF/MM. > > > > If zsmalloc is moving in the direction of supporting only zram, > > why should it be promoted into mm, or even lib? Why not promote > > zram into drivers and put zsmalloc.c in the same directory? >=20 > I don't want to make zsmalloc zram specific and will do best effort > to generalize it to all z* familiy. I'm glad to hear that. You may not know/remember that the split between "old zcache" and "new zcache" (and the fork to zswap) was started because some people refused to accept changes to zsmalloc to support a broader set of requirements. > If it is hard to reach out > agreement, yes, forking could be a easy solution like other embedded > product company but I don't want it. I don't want it either, so I think it is wise for us all to understand each others' objectives to see if we can avoid a fork. Or if the objectives are too different, then we have data to explain to other kernel developers why a fork is necessary. Thanks! Dan -- 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