On 03/08/2017 01:03 AM, Sagi Grimberg wrote:
>
>> - if (likely(blk_queue_enter(q, false) == 0)) {
>> + if (likely(blk_queue_enter(q, bio_flagged(bio, BIO_NOWAIT))
>> == 0)) {
>> ret = q->make_request_fn(q, bio);
>
> I think that for ->make_request to not block we'd need to set
> BLK_MQ_REQ_NOWAIT in blk_mq_alloc_data to avoid blocking on a tag
> allocation.
>
> Something like the untested addition below:
I did that in the first series, but there are too many reasons to block
in blk-mq [1]. I dropped blk-mq work in v2.
[1] https://patchwork.kernel.org/patch/9571051/
--
Goldwyn
