[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>
diff --git a/Documentation/power/interface.txt b/Documentation/power/interface.txt
index f5ebda5..bd4ffb5 100644
--- a/Documentation/power/interface.txt
+++ b/Documentation/power/interface.txt
@@ -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.