From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: slow susped to disk Date: Mon, 3 Apr 2006 11:47:16 +0200 Message-ID: <20060403094716.GC12475@elf.ucw.cz> References: <4430E44B.7070003@triumf.ca> <200604031128.02974.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from gprs189-60.eurotel.cz ([160.218.189.60]:61117 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S1751697AbWDCJr3 (ORCPT ); Mon, 3 Apr 2006 05:47:29 -0400 Content-Disposition: inline In-Reply-To: <200604031128.02974.rjw@sisk.pl> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: Zaher Salman , linux-acpi@vger.kernel.org Hi! > > I upgraded the kernel from 2.6.15 to 2.6.16 on my presario 2100. Both > > kernels were compiled with the similar configuration files. Anyway I > > found that suspend to disk (and resume) is much slower on 2.6.16 > > compared to 2.6.15. Any idea for why that might happen or how can I > > speed it up? There is also a big difference when suspending with the > > laptop plugged or not.. > > This is because the size of the suspend image is now greater than > for 2.6.15. > > There's the /sys/power/image_size knob that controls the size of the image. > If you set it to 0 (eg. by echo 0 > /sys/power/image_size as root), the > 2.6.15 behavior should be restored. However, if you set image_size > 0 > it should improve the system responsiveness after resume. > > Please refer to Documentation/power/interface.txt in the kernel tree for > details. If you don't mind, I have added it to the FAQ. diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt index 55e0006..3fcec52 100644 --- a/Documentation/power/swsusp.txt +++ b/Documentation/power/swsusp.txt @@ -396,4 +396,17 @@ mounted filesystem. With USB that's tru The safest thing is to unmount all USB-based filesystems before suspending and remount them after resuming. - +Q: I upgraded the kernel from 2.6.15 to 2.6.16. Both kernels were +compiled with the similar configuration files. Anyway I found that +suspend to disk (and resume) is much slower on 2.6.16 compared to +2.6.15. Any idea for why that might happen or how can I speed it up? + +A: This is because the size of the suspend image is now greater than +for 2.6.15 (by saving more data we can get more responsive system +after resume). + +There's the /sys/power/image_size knob that controls the size of the +image. If you set it to 0 (eg. by echo 0 > /sys/power/image_size as +root), the 2.6.15 behavior should be restored. If it is still too +slow, take a look at suspend.sf.net -- userland suspend is faster and +supports LZF compression to speed it up further. -- Picture of sleeping (Linux) penguin wanted...