From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 625DD8D0039 for ; Wed, 9 Feb 2011 18:57:38 -0500 (EST) Received: by iyi20 with SMTP id 20so748597iyi.14 for ; Wed, 09 Feb 2011 15:57:36 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <5c529b08-cf36-43c7-b368-f3f602faf358@default> References: <5c529b08-cf36-43c7-b368-f3f602faf358@default> Date: Thu, 10 Feb 2011 08:57:36 +0900 Message-ID: Subject: Re: [PATCH V2 2/3] drivers/staging: zcache: host services and PAM services From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Dan Magenheimer Cc: gregkh@suse.de, Chris Mason , akpm@linux-foundation.org, torvalds@linux-foundation.org, matthew@wil.cx, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ngupta@vflare.org, jeremy@goop.org, Kurt Hackel , npiggin@kernel.dk, riel@redhat.com, Konrad Wilk , mel@csn.ul.ie, kosaki.motohiro@jp.fujitsu.com, sfr@canb.auug.org.au, wfg@mail.ustc.edu.cn, tytso@mit.edu, viro@zeniv.linux.org.uk, hughd@google.com, hannes@cmpxchg.org On Thu, Feb 10, 2011 at 1:39 AM, Dan Magenheimer wrote: > > >> From: Minchan Kim [mailto:minchan.kim@gmail.com] > >> As I read your comment, I can't find the benefit of zram compared to >> frontswap. > > Well, I am biased, but I agree that frontswap is a better technical > solution than zram. ;-) =C2=A0But "dynamic-ity" is very important to > me and may be less important to others. > > I thought of these other differences, both technical and > non-technical: > > - Zram is minimally invasive to the swap subsystem, requiring only > =C2=A0one hook which is already upstream (though see below) and is > =C2=A0apparently already used by some Linux users. =C2=A0Frontswap is som= ewhat Yes. I think what someone is using it is a problem. > =C2=A0more invasive and, UNTIL zcache-was-kztmem was posted a few weeks > =C2=A0ago, had no non-Xen users (though some distros are already shipping > =C2=A0the hooks in their kernels because Xen supports it); as a result, > =C2=A0frontswap has gotten almost no review by kernel swap subsystem > =C2=A0experts who I'm guessing weren't interested in anything that > =C2=A0required Xen to use... hopefully that barrier is now resolved > =C2=A0(but bottom line is frontswap is not yet upstream). That's why I suggested to remove frontswap in this turn. If any swap experts has a interest, maybe you can't receive any ack or review about the part in this series. Maybe maintainers ends up hesitating the merge. If zcache except frontswap is merged into mainline or receive enough review, then you can try merging frontswap as further step. Thanks. --=20 Kind regards, Minchan Kim -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org