[PATCH 1/2] nvme-pci; remove the barriers nvme_irq()

[Jens Axboe]

On 2/18/21 11:37 PM, Chaitanya Kulkarni wrote:
> The barriers were added to the nvme_irq() in the
> commit 3a7afd8ee42a ("nvme-pci: remove the CQ lock for interrupt driven queues")
> to prevent compiler from doing memory optimization for the variabes that
> were protected previously by spinlock in nvme_irq() at completion queue
> processing and with queue head check condition..
> 
> The variable nvmeq->last_cq_head from those checks was removed in the
> commit f6c4d97b0d82 ("nvme/pci: Remove last_cq_head")") that was
> preventing  poll queues from mistakenly triggering the spurious
> interrupt detection.
> 
> Remove the barriers which were protecting the updates to the variables.

Would seem prudent to just ask the original submitter to send a v2
of his patch, as that's where it came from.

-- 
Jens Axboe