> > > > Today I am looking at one megaraid_sas related issue, and found > > > > pci_alloc_irq_vectors(PCI_IRQ_AFFINITY) is used in the driver, so > > > > looks each reply queue has been handled by more than one CPU if > > > > there are more CPUs than MSIx vectors in the system, which is done > > > > by generic irq affinity code, please see kernel/irq/affinity.c. > > > > Yes. That is a problematic area. If CPU and MSI-x(reply queue) is 1:1 > > mapped, we don't have any issue. > > I guess the problematic area is similar with the following link: > > https://marc.info/?l=linux-kernel&m=151748144730409&w=2 Hi Ming, Above mentioned link is different discussion and looks like a generic issue. megaraid_sas/mpt3sas will have same symptoms if irq affinity has only offline CPUs. Just for info - "In such condition, we can ask users to disable affinity hit via module parameter " smp_affinity_enable". > > otherwise could you explain a bit about the area? Please check below post for more details. https://marc.info/?l=linux-scsi&m=151601833418346&w=2
