From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RFC 09/15] PM / Hibernate: user, implement user_ops writer Date: Wed, 31 Mar 2010 22:29:18 +0200 Message-ID: <201003312229.18142.rjw@sisk.pl> References: <1269361063-3341-1-git-send-email-jslaby@suse.cz> <201003302250.26105.rjw@sisk.pl> <4BB35F1C.4030100@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BB35F1C.4030100@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Jiri Slaby Cc: linux-pm@lists.linux-foundation.org, Nigel Cunningham List-Id: linux-pm@vger.kernel.org On Wednesday 31 March 2010, Jiri Slaby wrote: > On 03/30/2010 10:50 PM, Rafael J. Wysocki wrote: > > So, I definitely would like to see numbers. > > With the patch attached, I get similar results for > uncompressed image -> user.c -> s2disk (compress+threads) > compressed image -> user.c -> s2disk (none of compress+threads) > > BUT note that there are differences in pages _copied_ in the "user.c -> > s2disk" phase. Compression was about 40 %. So in the former case 100000 > pages went through and in the latter one only ~ 38000. So presumably > there will be savings if the pages are compressed in the kernel in the > save-image phase instead of in userspace. > > I'll test (after I hack that up) also the case of image compression when > saving the image and let you know. > > It was tested on a machine with openSUSE factory with init 5 with KDE 4. > The memory consumption was ~ 400M (100000 pages) after boot every time. > Hibernation lasted 12-13s in both cases. So that's pretty much the same and I don't think feeding compressed images to s2disk is not worth the effort. Let's assume s2disk will always receive a raw image (that will make it backwards compatible too). Rafael