Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case
authorVitaly Kuznetsov <vkuznets@redhat.com>
Tue, 31 Mar 2015 18:16:40 +0000 (11:16 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 3 Apr 2015 14:20:12 +0000 (16:20 +0200)
commitba0c444153889a9b672974d85a4a57a8eeb49fe3
treea00bd2647a8943eabf0c136b249f869f437b3b79
parent6a84d63d22a0ac79ab422b69ef2b4d75002c5641
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>
drivers/hv/hv_balloon.c