[PATCH] swsusp: read speedup

Implement async reads for swsusp resuming.

Crufty old PIII testbox:
	15.7 MB/s -> 20.3 MB/s

Sony Vaio:
	14.6 MB/s -> 33.3 MB/s

I didn't implement the post-resume bio_set_pages_dirty().  I don't really
understand why resume needs to run set_page_dirty() against these pages.

It might be a worry that this code modifies PG_Uptodate, PG_Error and
PG_Locked against the image pages.  Can this possibly affect the resumed-into
kernel?  Hopefully not, if we're atomically restoring its mem_map?

Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Jens Axboe <axboe@suse.de>
Cc: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 57a792982fb9..59ce712f082d 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -58,6 +58,7 @@ struct snapshot_handle {
         struct pbe      *pbe, *last_pbe;
         void            *buffer;
         unsigned int    buf_offset;
+        int             sync_read;
 };
 
 #define data_of(handle) ((handle).buffer + (handle).buf_offset)