From: Rafael J. Wysocki Date: Fri, 6 Jan 2006 08:15:56 +0000 (-0800) Subject: [PATCH] swsusp: make image size limit tunable X-Git-Tag: MMI-PSA29.97-13-9~53665^2~160 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ca0aec0f7a94bf9f07fefa8bfd23282d4e8ceb8a;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git [PATCH] swsusp: make image size limit tunable Make the suspend image size limit tunable via /sys/power/image_size. It is necessary for systems on which there is a limited amount of swap available for suspend. It can also be useful for optimizing performance of swsusp on systems with 1 GB of RAM or more. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt index f5ebda5f4276..bd4ffb5bd49a 100644 --- a/Documentation/power/interface.txt +++ b/Documentation/power/interface.txt @@ -41,3 +41,14 @@ to. Writing to this file will accept one of 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. diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt index b0d50840788e..cd0fcd89a6f0 100644 --- a/Documentation/power/swsusp.txt +++ b/Documentation/power/swsusp.txt @@ -27,6 +27,11 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state 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: ------------------------ diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 9e51cdf7b78d..e24446f8d8cd 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -365,9 +365,29 @@ out: 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, }; diff --git a/kernel/power/power.h b/kernel/power/power.h index 9b0459903613..273a5b1d70be 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -52,11 +52,8 @@ extern const void __nosave_begin, __nosave_end; 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); diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c index 6d5ceaf4c364..d760a6a719f0 100644 --- a/kernel/power/swsusp.c +++ b/kernel/power/swsusp.c @@ -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 @@ int swsusp_shrink_memory(void) 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; }