diff options
| author | Vitaly Kuznetsov | 2015-03-31 11:16:40 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2015-04-03 16:20:12 +0200 |
| commit | ba0c444153889a9b672974d85a4a57a8eeb49fe3 (patch) | |
| tree | a00bd2647a8943eabf0c136b249f869f437b3b79 /drivers/hv | |
| parent | 6a84d63d22a0ac79ab422b69ef2b4d75002c5641 (diff) | |
Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
'Drivers: hv: hv_balloon: refuse to balloon below the floor' fix does not
correctly handle the case when val.freeram < num_pages as val.freeram is
__kernel_ulong_t and the 'val.freeram - num_pages' value will be a huge
positive value instead of being negative.
Usually host doesn't ask us to balloon more than val.freeram but in case
he have a memory hog started after we post the last pressure report we
can get into troubles.
Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/hv_balloon.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 74312c88534a..4052ad8255fa 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -1155,7 +1155,7 @@ static void balloon_up(struct work_struct *dummy) floor = compute_balloon_floor(); /* Refuse to balloon below the floor, keep the 2M granularity. */ - if (val.freeram - num_pages < floor) { + if (val.freeram < num_pages || val.freeram - num_pages < floor) { num_pages = val.freeram > floor ? (val.freeram - floor) : 0; num_pages -= num_pages % PAGES_IN_2M; } |