Re: [PATCH v2 1/1] xen/blkfront: always allocate grants first from per-queue persistent grants

From: Roger Pau Monné
Date: Wed Jun 28 2017 - 11:49:42 EST


On Wed, Jun 28, 2017 at 08:57:28PM +0800, Dongli Zhang wrote:
> This patch partially reverts 3df0e50 ("xen/blkfront: pseudo support for
> multi hardware queues/rings"). The xen-blkfront queue/ring might hang due
> to grants allocation failure in the situation when gnttab_free_head is
> almost empty while many persistent grants are reserved for this queue/ring.
>
> As persistent grants management was per-queue since 73716df ("xen/blkfront:
> make persistent grants pool per-queue"), we should always allocate from
> persistent grants first.
>
> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx>

Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

Thanks.