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

From: Dongli Zhang
Date: Wed Jul 19 2017 - 03:49:53 EST


Hi Konrad,

In addition to Junxiao's patch on xen-blkfront, would you please help merge this
to mainline as well?

Thank you very much!

Dongli Zhang

On 06/28/2017 11:34 PM, Roger Pau Monné wrote:
> 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.
>