[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 <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 20 insertions, 0 deletions

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,
 };