On 10/9/2026 9:00 PM, Keith Busch wrote:
On Fri, Oct 09, 2026 at 05:05:56AM +0000, Naman Jain wrote:static irqreturn_t nvme_irq(int irq, void *data) { struct nvme_queue *nvmeq = data; DEFINE_IO_COMP_BATCH(iob);+ if (unlikely(test_and_clear_bit(NVMEQ_IRQ_POLL_HANDOFF,+ &nvmeq->flags))) { + if (!nvme_cqe_pending(nvmeq)) + return IRQ_HANDLED; + } + if (unlikely(test_bit(NVMEQ_IRQ_POLL_PAUSED, &nvmeq->flags) && + (!test_bit(NVMEQ_IRQ_POLL_INIT, &nvmeq->flags) || + test_bit(NVMEQ_IRQ_POLL_MASKED, &nvmeq->flags) || + READ_ONCE(to_pci_dev(nvmeq->dev->dev)->error_state) != + pci_channel_io_normal))) + return IRQ_HANDLED; + + if (unlikely(in_hardirq() && + test_bit(NVMEQ_IRQ_POLL_INIT, &nvmeq->flags) && + !test_bit(NVMEQ_IRQ_POLL_PAUSED, &nvmeq->flags) && + need_resched() && nvme_cqe_pending(nvmeq) && + !test_and_set_bit_lock(NVMEQ_IRQ_POLL, &nvmeq->flags))) { + set_bit(NVMEQ_IRQ_POLL_MASKED, &nvmeq->flags); + disable_irq_nosync(irq); + irq_poll_sched(&nvmeq->iopoll); + return IRQ_HANDLED; + }The disable_irq_nosync still does non-posted transactions for msi and msi-x. NVMe has a shortcut for msi, but there's currently nothing for msi-x. For that case, I have a prep patch I consulted with Thomas, and the result is below. I'm delayed sending it out while catching up from travel, but I think this will be even more efficient.
Thanks for sharing. I'll give it a try. IIUC, after your patch goes in, I should be using disable_irq_nowait() in above and see better performance. Please correct me if I am wrong. I'll monitor your patch in LKML for future versions.
Regards, Naman
