On 16/04/2021 01:46, Ming Lei wrote:
I can't seem to recreate your same issue. Are you mainline defconfig, or a
special disto config?
The config is rhel8 config.
Can you share that? Has anyone tested against mainline x86 config?
As I mentioned, with deadline, IOPS drop is observed on one hardware(ibm-x3850x6)
which is exactly the machine Yanhui reported the cpu utilization issue.
On another machine(HP DL380G10), still 32cores, dual numa nodes, IOPS drop can't be
observed, but cpu utilization difference is still obserable.
I use scsi_debug just because it is hard to run the virt workloads on
that machine. And the reported issue is on megaraid_sas, which is a scsi
device, so null_blk isn't good to simulate here because it can't cover
scsi stack.
Understood. Apart from scsi_debug, the only thing I can readily compare
hosttags vs non-hosttags for scsi stack on is a megaraid_sas system with
1x SATA disk. Or hack with hisi_sas to support both.
Thanks,
John
