On 11/25/2014 12:32 PM, Dexuan Cui wrote:
> If num_ballooned is not 0, we shouldn't neglect the
> already-partially-allocated 2MB memory block(s).
>
> Cc: Jason Wang <jasowang@xxxxxxxxxx>
> Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> ---
>
> v2: I fixed the logic error in v1, pointed by Jason Wang:
> In v1: in the case of partially-allocated 2MB, alloc_error is true,
> so we'll run "done = true" and hence we won't proceed with
> the next iteration of trying 4K allocation.
>
> I also changed the WARN_ON to WARN_ON_ONCE in case the host behavior
> changes in the future.
>
> drivers/hv/hv_balloon.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 5e90c5d..b958ded 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -1087,10 +1087,12 @@ static void balloon_up(struct work_struct *dummy)
> struct dm_balloon_response *bl_resp;
> int alloc_unit;
> int ret;
> - bool alloc_error = false;
> + bool alloc_error;
> bool done = false;
> int i;
>
> + /* The host balloons pages in 2M granularity. */
> + WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0);
>
> /*
> * We will attempt 2M allocations. However, if we fail to
> @@ -1107,16 +1109,18 @@ static void balloon_up(struct work_struct *dummy)
>
>
> num_pages -= num_ballooned;
> + alloc_error = false;
> num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
> bl_resp, alloc_unit,
> &alloc_error);
>
> - if ((alloc_error) && (alloc_unit != 1)) {
> + if (alloc_unit != 1 && num_ballooned == 0) {
> alloc_unit = 1;
> continue;
> }
>
> - if ((alloc_error) || (num_ballooned == num_pages)) {
> + if ((alloc_unit == 1 && alloc_error) ||
> + (num_ballooned == num_pages)) {
> bl_resp->more_pages = 0;
> done = true;
> dm_device.state = DM_INITIALIZED;
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
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