From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bojan Smojver Subject: Re: [PATCH] PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image Date: Thu, 29 Dec 2011 13:58:51 +1100 Message-ID: <1325127531.2029.13.camel@shrek.rexursive.com> References: <1325115628.2029.1.camel@shrek.rexursive.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Barry Song <21cnbao@gmail.com> Cc: linux-pm@lists.linux-foundation.org, LKML , DL-SHA-WorkGroupLinux List-Id: linux-pm@vger.kernel.org On Thu, 2011-12-29 at 10:37 +0800, Barry Song wrote: > i mean we can load image and decompress them in different threads when > we reboot from hibernation. after i read codes more carefully, that > has actually been done by lzo_decompress_threadfn(). Correct. Both hibernation and thaw are multi-threaded. > here the problem is we didn't seem to get any faster after applying > your compression patch when doing hibernation on SD/NAND. > we are trying to figure out the reason. This may depend on many factors: - how much CPU power you have - how many CPUs you have - how much I/O can your disk do Remember, there is one thread that does CRC32 as well and other threads will have to sync with that thread. Anyhow, it would be interesting to know where the bottleneck is on your particular system. If you system has lots of CPU power and fast I/O, the patch indeed may not do anything at all. PS. I did my testing on a ThinkPad T510 laptop. It has a Core i5 M520 2.4 GHz mobile CPU (this appears to the system as 4 CPUs - it's two physical cores with hyper-threading enabled). The disk is classic platter based disk (Seagate ST9500420AS). There is 8 GB of RAM on this system. -- Bojan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751957Ab1L2C6z (ORCPT ); Wed, 28 Dec 2011 21:58:55 -0500 Received: from beauty.rexursive.com ([150.101.121.179]:47524 "EHLO beauty.rexursive.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141Ab1L2C6x (ORCPT ); Wed, 28 Dec 2011 21:58:53 -0500 Message-ID: <1325127531.2029.13.camel@shrek.rexursive.com> Subject: Re: [PATCH] PM / Hibernate: Improve performance of LZO/plain hibernation, checksum image From: Bojan Smojver To: Barry Song <21cnbao@gmail.com> Cc: rjw@sisk.pl, linux-pm@lists.linux-foundation.org, LKML , DL-SHA-WorkGroupLinux Date: Thu, 29 Dec 2011 13:58:51 +1100 In-Reply-To: References: <1325115628.2029.1.camel@shrek.rexursive.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2 (3.2.2-1.fc16) Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-12-29 at 10:37 +0800, Barry Song wrote: > i mean we can load image and decompress them in different threads when > we reboot from hibernation. after i read codes more carefully, that > has actually been done by lzo_decompress_threadfn(). Correct. Both hibernation and thaw are multi-threaded. > here the problem is we didn't seem to get any faster after applying > your compression patch when doing hibernation on SD/NAND. > we are trying to figure out the reason. This may depend on many factors: - how much CPU power you have - how many CPUs you have - how much I/O can your disk do Remember, there is one thread that does CRC32 as well and other threads will have to sync with that thread. Anyhow, it would be interesting to know where the bottleneck is on your particular system. If you system has lots of CPU power and fast I/O, the patch indeed may not do anything at all. PS. I did my testing on a ThinkPad T510 laptop. It has a Core i5 M520 2.4 GHz mobile CPU (this appears to the system as 4 CPUs - it's two physical cores with hyper-threading enabled). The disk is classic platter based disk (Seagate ST9500420AS). There is 8 GB of RAM on this system. -- Bojan