From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx187.postini.com [74.125.245.187]) by kanga.kvack.org (Postfix) with SMTP id DF32F6B0006 for ; Fri, 18 Jan 2013 15:20:50 -0500 (EST) MIME-Version: 1.0 Message-ID: <224b1c8a-2ae0-486b-bfdd-4a161f662afd@default> Date: Fri, 18 Jan 2013 12:19:17 -0800 (PST) From: Dan Magenheimer Subject: RE: [PATCH 1/3] zram: force disksize setting before using zram References: <1358388769-30112-1-git-send-email-minchan@kernel.org> <20130118004219.GB29380@kroah.com> In-Reply-To: <20130118004219.GB29380@kroah.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Greg Kroah-Hartman , Minchan Kim Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Nitin Gupta , Seth Jennings , Konrad Rzeszutek Wilk , Jerome Marchand , Pekka Enberg > From: Greg Kroah-Hartman [mailto:gregkh@linuxfoundation.org] > Sent: Thursday, January 17, 2013 5:42 PM > To: Minchan Kim > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; Nitin Gupta; Seth J= ennings; Dan Magenheimer; > Konrad Rzeszutek Wilk; Jerome Marchand; Pekka Enberg > Subject: Re: [PATCH 1/3] zram: force disksize setting before using zram >=20 > On Thu, Jan 17, 2013 at 11:12:47AM +0900, Minchan Kim wrote: > > Now zram document syas "set disksize is optional" > > but partly it's wrong. When you try to use zram firstly after > > booting, you must set disksize, otherwise zram can't work because > > zram gendisk's size is 0. But once you do it, you can use zram freely > > after reset because reset doesn't reset to zero paradoxically. > > So in this time, disksize setting is optional.:( > > It's inconsitent for user behavior and not straightforward. > > > > This patch forces always setting disksize firstly before using zram. > > Yes. It changes current behavior so someone could complain when > > he upgrades zram. Apparently it could be a problem if zram is mainline > > but it still lives in staging so behavior could be changed for right > > way to go. Let them excuse. >=20 > I don't know about changing this behavior. I need some acks from some > of the other zram developers before I can take this, or any of the other > patches in this series. I'm not officially a zram developer, but I have used it and I am knowledgeable about in-kernel compression and know the specific problem being fixed here. Unless/until compression is much more tightly integrated into MM policies and "z*" can manage space more dynamically, Minchan's patch seems to be a good way to go, especially since zram has found a solid niche in the embedded (no swap disk) community. So FWIW: Acked-by: Dan Magenheimer -- 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