Jonathan Derrick <jonathan.derrick@xxxxxxxxx> 于2022年12月28日周三 06:32写道： > > The bypass mode should help in the cases where drives irqs (eg nproc) exceed > VMD I/O irqs. VMD I/O irqs for 28c0 should be min(63, nproc). You have > very few cpus for a Skylake system with that many drives, unless you mean you > are explicitly restricting the 12 drives to only 6 cpus. Either way, bypass mode > is effectively VMD-disabled, which points to other issues. Though I have also seen > much smaller interrupt aggregation benefits. Firstly，I am sorry for my words misleading you. We totally tested 12 drives. And each drive run in 6 CPU cores with 8 jobs. Secondly, I try to test the drives with VMD disabled,I found the results to be largely consistent with bypass mode. I suppose the bypass mode just "bypass" the VMD controller. The last one，we found in bypass mode the CPU idle is 91%. But in remapping mode the CPU idle is 78%. And the bypass's context-switchs is much fewer than the remapping mode's. It seems the system is watiing for something in bypass mode.
