xen/balloon: Avoid OOM when requesting highmem

If highmem pages are requested from the balloon on a system without
highmem, the implementation of alloc_xenballooned_pages will allocate
all available memory trying to find highmem pages to return. Allow
low memory to be returned when highmem pages are requested to avoid
this loop.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Daniel De Graaf 2011-10-19 17:59:37 -04:00 committed by Konrad Rzeszutek Wilk
parent 5f76d7078c
commit 72e9cf2ab1
1 changed files with 2 additions and 2 deletions

View File

@ -501,7 +501,7 @@ EXPORT_SYMBOL_GPL(balloon_set_new_target);
* alloc_xenballooned_pages - get pages that have been ballooned out
* @nr_pages: Number of pages to get
* @pages: pages returned
* @highmem: highmem or lowmem pages
* @highmem: allow highmem pages
* @return 0 on success, error otherwise
*/
int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
@ -511,7 +511,7 @@ int alloc_xenballooned_pages(int nr_pages, struct page **pages, bool highmem)
mutex_lock(&balloon_mutex);
while (pgno < nr_pages) {
page = balloon_retrieve(highmem);
if (page && PageHighMem(page) == highmem) {
if (page && (highmem || !PageHighMem(page))) {
pages[pgno++] = page;
} else {
enum bp_state st;