Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750738AbVLJWzN (ORCPT ); Sat, 10 Dec 2005 17:55:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751290AbVLJWzN (ORCPT ); Sat, 10 Dec 2005 17:55:13 -0500 Received: from anf141.internetdsl.tpnet.pl ([83.17.87.141]:60881 "EHLO anf141.internetdsl.tpnet.pl") by vger.kernel.org with ESMTP id S1750738AbVLJWzL (ORCPT ); Sat, 10 Dec 2005 17:55:11 -0500 From: "Rafael J. Wysocki" To: Pavel Machek Subject: Re: [RFC/RFT] swsusp: image size tunable (was: Re: [PATCH][mm] swsusp: limit image size) Date: Sat, 10 Dec 2005 23:56:26 +0100 User-Agent: KMail/1.9 Cc: Stefan Seyfried , LKML , Andy Isaacson References: <200512072246.06222.rjw@sisk.pl> <20051210160641.GB5047@elf.ucw.cz> <200512102106.41952.rjw@sisk.pl> In-Reply-To: <200512102106.41952.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200512102356.27271.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5515 Lines: 150 Update: On Saturday, 10 December 2005 21:06, Rafael J. Wysocki wrote: > On Saturday, 10 December 2005 17:06, Pavel Machek wrote: > > > > The tunable may be useful to people who'd like to achieve the > > > > maximum efficiency of suspend/resume and it would be a nice > > > > feature to have, I think, but let's say we'll try to implement it > > > > in the future, if still needed/wanted. > > > > > > Actually the tunable turned out to be quite easy to implement and I think > > > I'll need it for userspace swsusp (the suspend-handling userspace > > > process will need to tell the kernel how much space there is for the > > > image). > > > > Looks mostly okay to me, small comments below. A cleaner version with comments etc. follows. Rafael Signed-off-by: Rafael J. Wysocki Documentation/power/interface.txt | 11 +++++++++++ Documentation/power/swsusp.txt | 7 ++++++- kernel/power/disk.c | 20 ++++++++++++++++++++ kernel/power/power.h | 7 ++----- kernel/power/swsusp.c | 10 +++++++++- 5 files changed, 48 insertions(+), 7 deletions(-) Index: linux-2.6.15-rc5-mm1/kernel/power/disk.c =================================================================== --- linux-2.6.15-rc5-mm1.orig/kernel/power/disk.c 2005-12-07 23:19:03.000000000 +0100 +++ linux-2.6.15-rc5-mm1/kernel/power/disk.c 2005-12-10 21:10:53.000000000 +0100 @@ -367,9 +367,29 @@ power_attr(resume); +static ssize_t image_size_show(struct subsystem * subsys, char *buf) +{ + return sprintf(buf, "%u\n", image_size); +} + +static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n) +{ + unsigned int size; + + if (sscanf(buf, "%u", &size) == 1) { + image_size = size; + return n; + } + + return -EINVAL; +} + +power_attr(image_size); + static struct attribute * g[] = { &disk_attr.attr, &resume_attr.attr, + &image_size_attr.attr, NULL, }; Index: linux-2.6.15-rc5-mm1/kernel/power/power.h =================================================================== --- linux-2.6.15-rc5-mm1.orig/kernel/power/power.h 2005-12-10 20:59:52.000000000 +0100 +++ linux-2.6.15-rc5-mm1/kernel/power/power.h 2005-12-10 21:13:04.000000000 +0100 @@ -52,11 +52,8 @@ extern unsigned int nr_copy_pages; extern struct pbe *pagedir_nosave; -/* - * Preferred image size in MB (set it to zero to get the smallest - * image possible) - */ -#define IMAGE_SIZE 500 +/* Preferred image size in MB (default 500) */ +extern unsigned int image_size; extern asmlinkage int swsusp_arch_suspend(void); extern asmlinkage int swsusp_arch_resume(void); Index: linux-2.6.15-rc5-mm1/kernel/power/swsusp.c =================================================================== --- linux-2.6.15-rc5-mm1.orig/kernel/power/swsusp.c 2005-12-10 20:59:52.000000000 +0100 +++ linux-2.6.15-rc5-mm1/kernel/power/swsusp.c 2005-12-10 22:21:25.000000000 +0100 @@ -69,6 +69,14 @@ #include "power.h" +/* + * Preferred image size in MB (tunable via /sys/power/image_size). + * When it is set to N, swsusp will do its best to ensure the image + * size will not exceed N MB, but if that is impossible, it will + * try to create the smallest image possible. + */ +unsigned int image_size = 500; + #ifdef CONFIG_HIGHMEM unsigned int count_highmem_pages(void); int save_highmem(void); @@ -647,7 +655,7 @@ if (!tmp) return -ENOMEM; pages += tmp; - } else if (size > (IMAGE_SIZE * 1024 * 1024) / PAGE_SIZE) { + } else if (size > (image_size * 1024 * 1024) / PAGE_SIZE) { tmp = shrink_all_memory(SHRINK_BITE); pages += tmp; } Index: linux-2.6.15-rc5-mm1/Documentation/power/swsusp.txt =================================================================== --- linux-2.6.15-rc5-mm1.orig/Documentation/power/swsusp.txt 2005-10-28 02:02:08.000000000 +0200 +++ linux-2.6.15-rc5-mm1/Documentation/power/swsusp.txt 2005-12-10 23:49:08.000000000 +0100 @@ -27,6 +27,11 @@ echo platform > /sys/power/disk; echo disk > /sys/power/state +If you want to limit the suspend image size to N megabytes, do + +echo N > /sys/power/image_size + +before suspend (it is limited to 500 MB by default). Encrypted suspend image: ------------------------ Index: linux-2.6.15-rc5-mm1/Documentation/power/interface.txt =================================================================== --- linux-2.6.15-rc5-mm1.orig/Documentation/power/interface.txt 2005-10-28 02:02:08.000000000 +0200 +++ linux-2.6.15-rc5-mm1/Documentation/power/interface.txt 2005-12-10 23:42:39.000000000 +0100 @@ -41,3 +41,14 @@ It will only change to 'firmware' or 'platform' if the system supports it. +/sys/power/image_size controls the size of the image created by +the suspend-to-disk mechanism. It can be written a string +representing a non-negative integer that will be used as an upper +limit of the image size, in megabytes. The suspend-to-disk mechanism will +do its best to ensure the image size will not exceed that number. However, +if this turns out to be impossible, it will try to suspend anyway using the +smallest image possible. In particular, if "0" is written to this file, the +suspend image will be as small as possible. + +Reading from this file will display the current image size limit, which +is set to 500 MB by default. - 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/