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>
This commit is contained in:
Vitaly Kuznetsov 2015-02-28 11:39:00 -08:00 committed by Greg Kroah-Hartman
parent 549fd280b1
commit 530d15b907
1 changed files with 11 additions and 0 deletions

View File

@ -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);