PM / Hibernate: Fix preallocating of memory

commit a9c9b4429df437982d2fbfab1f4b46b01329e9ed upstream.

The hibernate memory preallocation code allocates memory to push some
user space data out of physical RAM, so that the hibernation image is
not too large.  It allocates more memory than necessary for creating
the image, so it has to release some pages to make room for
allocations made while suspending devices and disabling nonboot CPUs,
or the system will hang due to the lack of free pages to allocate
from.  Unfortunately, the function used for freeing these pages,
free_unnecessary_pages(), contains a bug that prevents it from doing
the job on all systems without highmem.

Fix this problem, which is a regression from the 2.6.30 kernel, by
using the right condition for the termination of the loop in
free_unnecessary_pages().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Alan Jenkins <sourcejedi.lkml@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 36cb168e4330936a9120691fd19e80ddb8d2db9d..fc9ed15dcf03039760f92fa3150fd5c2162c1fd1 100644 (file)
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1181,7 +1181,7 @@ static void free_unnecessary_pages(void)
 
        memory_bm_position_reset(&copy_bm);
 
-       while (to_free_normal > 0 && to_free_highmem > 0) {
+       while (to_free_normal > 0 || to_free_highmem > 0) {
                unsigned long pfn = memory_bm_next_pfn(&copy_bm);
                struct page *page = pfn_to_page(pfn);