On Tue, Oct 31, 2017 at 02:29:32PM -0600, Jens Axboe wrote:

On 10/26/2017 10:43 PM, Ming Lei wrote:

quoted

Hi Jens,

The 1st patch removes the RESTART for TAG-SHARED because SCSI handles it
by itself, and not necessary to waste CPU to do the expensive RESTART.
And Roman Pen reported that this RESTART cuts half of IOPS in his case.

The 2nd patch removes the RESTART when .get_budget returns BLK_STS_RESOURCE,
and this RESTART is handled by SCSI's RESTART(scsi_end_request()) too.

What base is this against?

The for-next branch of your block tree:

--
Ming