Bug 212858

Summary: FreeBSD 11-stable regression in storage IOPS
Product: Base System Reporter: patdung100
Component: kernAssignee: freebsd-virtualization (Nobody) <virtualization>
Status: New ---    
Severity: Affects Only Me CC: decui, honzhan, sepherosa
Priority: ---    
Version: 11.0-STABLE   
Hardware: amd64   
OS: Any   

Description patdung100 2016-09-20 15:52:13 UTC
I have this VM (FreeBSD 10.3) in this setting:

KVM (Fedora 24)
VM (FreeBSD 10.3) and there are virtio-scsi disks connected to the VM:
1) OS disk
2) ZFS data disks

All three files in host file system is file based. The files are stored in the SSD.

I have done fio IO test in the FreeBSD VM:

The bandwidth and IO is :
READ bw=14709KB/s, iops=3677
WRITE bw=4898.8KB/s, iops=1224

After changing the VM to FreeBSD 11.0-stable, other settings remain the same.
I do fio IO test again.

The new statistics is:
READ bw=5651.3KB/s, iops=1412
WRITE bw=1889.1KB/s, iops=472

For reference, the command for fio:
fio --filename=./testfile --direct=1 --rw=randrw --refill_buffers --norandommap --randrepeat=0 --ioengine=sync --bs=4k --rwmixread=75 --iodepth=16 --numjobs=8 --runtime=60 --group_reporting --fsync=1 --name=4ktest -size=4G
Comment 1 Sepherosa Ziehau 2016-09-22 03:20:41 UTC
Possible to test current w/o WITNESS and INVARIANTS?  Since most perf related stuffs in current have not been MFC'ed to 11-stable.
Comment 2 Sepherosa Ziehau 2016-09-22 07:48:51 UTC
Sorry, I misread your report thought it was on Hyper-V...
Comment 3 patdung100 2016-09-22 10:26:32 UTC
(In reply to Sepherosa Ziehau from comment #2)

No problem.

I did a test on FreeBSD 12-current without witeness and invariant.

It is faster than FreeBSD 11-stable but slower than FreeBSD 10...

READ bw=7191.4KB/s, iops=1797
WRITE bw=2412.9KB/s, iops=603