From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 30F728D003A for ; Thu, 20 Jan 2011 08:16:03 -0500 (EST) Received: by ywj3 with SMTP id 3so174808ywj.14 for ; Thu, 20 Jan 2011 05:16:00 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20110120124730.GA7284@infradead.org> References: <9e7aa896-ed1f-4d50-8227-3a922be39949@default> <4D382B99.7070005@vflare.org> <20110120124730.GA7284@infradead.org> Date: Thu, 20 Jan 2011 15:16:00 +0200 Message-ID: Subject: Re: [PATCH 0/8] zcache: page cache compression support From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Christoph Hellwig Cc: Nitin Gupta , Dan Magenheimer , "Kirill A. Shutemov" , Pekka Enberg , Hugh Dickins , Andrew Morton , Greg KH , Rik van Riel , Avi Kivity , Minchan Kim , Konrad Wilk , linux-mm , linux-kernel List-ID: Hi Christoph, On Thu, Jan 20, 2011 at 07:33:29AM -0500, Nitin Gupta wrote: >> I just started looking into kztmem (weird name!) but on >> the high level it seems so much similar to zcache with some >> dynamic resizing added (callback for shrinker interface). >> >> Now, I'll try rebuilding zcache according to new cleancache >> API as provided by these set of patches. This will help refresh >> whatever issues I was having back then with pagecache >> compression and maybe pick useful bits/directions from >> new kztmem work. On Thu, Jan 20, 2011 at 2:47 PM, Christoph Hellwig wrot= e: > Yes, we shouldn't have two drivers doing almost the same in the > tree. =A0Also adding core hooks for staging drivers really is against > the idea of staging of having a separate crap tree. =A0So it would be > good to get zcache into a state where we can merge it into the > proper tree first. =A0And then we can discuss if adding an abstraction > layer between it and the core VM really makes sense, and if it does > how. =A0 But I'm pretty sure there's now need for multiple layers of > abstraction for something that's relatively core VM functionality. > > E.g. the abstraction should involve because of it's users, not the > compressed caching code should involve because it's needed to present > a user for otherwise useless code. I'm not sure which hooks you're referring to but for zcache we did this: http://git.kernel.org/?p=3Dlinux/kernel/git/torvalds/linux-2.6.git;a=3Dcomm= itdiff;h=3Db3a27d0529c6e5206f1b60f60263e3ecfd0d77cb I completely agree with getting zcache merged properly before going for the cleancache stuff. Pekka -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org