Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756135Ab1BIXqm (ORCPT ); Wed, 9 Feb 2011 18:46:42 -0500 Received: from mail-iw0-f174.google.com ([209.85.214.174]:56586 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754261Ab1BIXql convert rfc822-to-8bit (ORCPT ); Wed, 9 Feb 2011 18:46:41 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=NshZuXEO4TeahGJsZlJSxm3EJhAmqfMdDaKd9xag5Eq2FIGtqXUJJuO3HV3f1ly7KO MJID+fCI73v5fTL9Yq8T1rH6ryDXD+u5HcUIRYZLvX4RzT117M4HErylr4svKjZikFlM aBAnGiJ0nGt9RVF6e9CsxheZzrV7G/yxgRpV4= MIME-Version: 1.0 In-Reply-To: <4D52D091.1000504@vflare.org> References: <5c529b08-cf36-43c7-b368-f3f602faf358@default> <4D52D091.1000504@vflare.org> Date: Thu, 10 Feb 2011 08:46:40 +0900 Message-ID: Subject: Re: [PATCH V2 2/3] drivers/staging: zcache: host services and PAM services From: Minchan Kim To: Nitin Gupta Cc: Dan Magenheimer , 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, 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1758 Lines: 59 Hi Nitin, Sorry for late response. On Thu, Feb 10, 2011 at 2:36 AM, Nitin Gupta wrote: > On 02/09/2011 11:39 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. ;-)  But "dynamic-ity" is very important to >> me and may be less important to others. >> > > > I agree that frontswap is better than zram when considering swap as the use > case - no bio overhead, dynamic resizing. However, zram being a *generic* > block-device has some unique cases too like hosting files on /tmp, various > caches under /var or any place where a compressed in-memory block device can > help. Yes. I mentioned that benefit but I am not sure the reason is enough. What I had in mind long time ago is that zram's functionality into brd. So someone who want to compress contents could use it with some mount option to enable compression. By such way, many ramdisk user can turn it on easily. If many user begin using the brd, we can see many report about performance then solve brd performance s as well as zcache world-wide usage. Hmm, the idea is too late? > > So, frontswap and zram have overlapping use case of swap but are not the > same. If we can insert zram's functionality into brd, maybe there is no reason to coexist. > > Thanks, > Nitin > -- Kind regards, Minchan Kim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/