On 8/2/21 6:34 AM, yukuai (C) wrote:
I run a test on both null_blk and nvme, results show that there are no
performance degradation:
test platform: x86
test cpu: 2 nodes, total 72
test scheduler: none
test device: null_blk / nvme
test cmd: fio -filename=/dev/xxx -name=test -ioengine=libaio -direct=1
-numjobs=72 -iodepth=16 -bs=4k -rw=write -offset_increment=1G
-cpus_allowed=0:71 -cpus_allowed_policy=split -group_reporting
-runtime=120
test results: iops
1) null_blk before this patch: 280k
2) null_blk after this patch: 282k
3) nvme before this patch: 378k
4) nvme after this patch: 384k
Please use io_uring for performance tests.
The null_blk numbers seem way too low to me. If I run a null_blk
performance test inside a VM with 6 CPU cores (Xeon W-2135 CPU) I see
about 6 million IOPS for synchronous I/O and about 4.4 million IOPS when
using libaio. The options I used and that are not in the above command
line are: --thread --gtod_reduce=1 --ioscheduler=none.
Thanks,
Bart.
