Re: [PATCH v15,RESEND 22/23] PCI: starfive: Offload the NVMe timeout workaround to host drivers.

Keith Busch
2024-03-14T03:39:39Z

On Wed, Mar 13, 2024 at 08:51:29PM -0600, Keith Busch wrote:
> I suppose we could quirk a non-posted transaction in the interrupt
> handler to force flush pending memory updates, but that will noticeably
> harm your nvme performance. Maybe if you constrain such behavior to the
> spurious IRQ_NONE condition, then it might be okay? I don't know.

Hm, that may not be good enough: if nvme completions can be reordered
with their msi's, then I assume data may reorder with their completion.
Your application will inevitably see stale and corrupted data, so it
sounds like you need some kind of barrier per completion. Ouch!