I am trying to understand the result that the nvme driver has when it calls pci_alloc_irq_vectors_affinity() from nvme_setup_irqs() (drivers/nvme/host/pci.c) $ cat /proc/interrupts | grep nvme 63: 9 0 0 0 PCI-MSIX-0000:00:04.0 0-edge nvme0q0 64: 0 0 0 237894 PCI-MSIX-0000:00:04.0 1-edge nvme0q1 $ cat /proc/irq/64/smp_affinity_list 0-3 $ cat /proc/irq/64/effective_affinity_list 3 I think that this happens somewhere below pci_msi_setup_msi_irqs() (drivers/pci/msi/irqdomain.c) but I am losing track of what is done precisely because I am not sure of what is the irq_domain on my system. I have experimented by playing with the nvme io queues num that is passed to pci_msi_setup_msi_irqs() as the max_vectors params. The set irq effective affinity appears to always be the last cpu of the affinity mask. I would like to have some control on the selected effective_affinity as I am trying to use NOHZ_FULL effectively on my system. NOTE: I am NOT using irqbalance thank you,
