[RESEND RFC PATCH v2] nvme-pci: add adaptive interrupt polling

[Keith Busch]

On Thu, Aug 13, 2026 at 09:15:31AM +0530, Anuj Gupta wrote:
> 
> I also had a similar assesment on DIM. Emperically, with Keith's POC
> interrupts per IO drop from ~1.0 to ~0.29 but with a small performance
> regression (572K -> 557K IOPS). With your original approach they drop to
> ~0.03 with a 23% performance gain. The DIM machinery overhead maybe
> outweighing the partial interrupt reduction.

I may ultimately adandon this suggestion, but it looks like a major
factor in performance loss was from using IRQ_WAKE_THREAD with sleep
cycles instead of the softirq hrtimer. Just changing that is getting me
back to performance parity, but since it's not any better, perhaps the
hill climb is a worse algorithm than trying to reason out the delayed
poll time directly.