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authorVitaly Kuznetsov <vkuznets@redhat.com>2015-02-28 22:39:00 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-02 06:31:47 +0300
commit530d15b907038735d4cb008dc5caae7ce4dfc985 (patch)
treed2aabc77cd6e1da385959ddc4d2910c59eb39520
parent549fd280b145e2154db5a7d06981d041f8bbf597 (diff)
downloadlinux-530d15b907038735d4cb008dc5caae7ce4dfc985.tar.xz
Drivers: hv: hv_balloon: refuse to balloon below the floor
When host asks us to balloon up we need to be sure we're not committing suicide by overballooning. Use already existent 'floor' metric as our lowest possible value for free ram. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/hv/hv_balloon.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 53932b3e1973..c5bb87244dd7 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1138,6 +1138,8 @@ static void balloon_up(struct work_struct *dummy)
bool alloc_error;
bool done = false;
int i;
+ struct sysinfo val;
+ unsigned long floor;
/* The host balloons pages in 2M granularity. */
WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0);
@@ -1148,6 +1150,15 @@ static void balloon_up(struct work_struct *dummy)
*/
alloc_unit = 512;
+ si_meminfo(&val);
+ floor = compute_balloon_floor();
+
+ /* Refuse to balloon below the floor, keep the 2M granularity. */
+ if (val.freeram - num_pages < floor) {
+ num_pages = val.freeram > floor ? (val.freeram - floor) : 0;
+ num_pages -= num_pages % PAGES_IN_2M;
+ }
+
while (!done) {
bl_resp = (struct dm_balloon_response *)send_buffer;
memset(send_buffer, 0, PAGE_SIZE);