[viostor] Why does the performance of the viostor driver decrease

[york-king]

During the performance test, we found that 4K random read / write (70% read). The latest version of the driver (100.93.104.24000) is much less effective than the previous version (100.83.104.18700).

• Guest：win2016 1607

• 187 version:

• 240 verion:

• Through comparison, we found that the performance of the driver started to deteriorate in version 100.83.104.18900;

189 version:

[vrozenfe]

@york-king

There were several changes related to the performance optimization and the maximum transfer size
between build 187 and 189.
Can you please post the qemu command line and IoMeter config file? And also by any chance, can you please
check if there is any performance gap between builds 187 and 189 when testing 2MB block transfer?

Best regards,
Vadim.

[york-king]

hi, @vrozenfe

• Here are some test data, and the results show that the 189 version has slightly worse results

viostor version	Access Specification Name	IOps	MiBps (Binary)	MBps (Decimal)	Average Response Time	Maximum Response Time	Queue Depth
187	2M seq 7:3	3108.403165	6216.80633	6518.793914	20.585675	44.318452	64
189	2M seq 7:3	2990.892708	5981.785416	6272.356624	21.394941	64.518173	64
187	4k rand 7:3	157117.7947	613.741386	643.554487	0.407103	16.148202	64
189	4k rand 7:3	142701.3418	557.427116	584.504696	0.448277	26.656851	64
187	8k rand 7:3	155963.8894	1218.467886	1277.656182	0.410124	32.596539	64
189	8k rand 7:3	135979.9638	1062.343467	1113.947864	0.470435	30.947232	64

• qemu command line：

/usr/bin/kvm -id 1384900388335 -chardev socket,id=qmp,path=/var/run/qemu-server/1384900388335.qmp,server,nowait -mon chardev=qmp,mode=control -vnc 0.0.0.0:8100,websocket=14500,to=15000 -enable-kvm -pidfile /var/run/qemu-server/1384900388335.pid -name "viostorperftest" -cpu host,hv_spinlocks=0x1fff,hv_relaxed,hv_time,hv_vapic,hv_stimer,hv_synic,hv_vpindex,hv-runtime,+sse4.1,+sse4.2,+x2apic,+pcid,+pdcm,+xtpr,+ht,+ss,+acpi,+ds,migratable=no,+invtsc,-vmx,vendor=GenuineIntel -nodefaults
-device ich9-usb-ehci1,id=usb,bus=pci.0,addr=0x18.0x7
-device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pci.0,multifunction=on,addr=0x18
-device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pci.0,addr=0x18.0x1
-device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pci.0,addr=0x18.0x2 -spice port=0,disable-ticketing,up_port=13999,down_port=13500,os_type=ws1664,jpeg-wan-compression=never,jpeg_quality=85,streaming-video=filter -chardev spicevmc,id=charredir0,name=usbredir
-device usb-redir,bus=usb.0,port=1,chardev=charredir0,id=ehci-redir0,bootindex=10 -chardev spicevmc,id=charredir1,name=usbredir
-device usb-redir,bus=usb.0,port=2,chardev=charredir1,id=ehci-redir1,bootindex=11 -chardev spicevmc,id=charredir2,name=usbredir
-device usb-redir,bus=usb.0,port=3,chardev=charredir2,id=ehci-redir2,bootindex=12 -chardev spicevmc,id=charredir3,name=usbredir
-device usb-redir,bus=usb.0,port=4,chardev=charredir3,id=ehci-redir3,bootindex=13 -chardev spicevmc,id=charredir4,name=usbredir
-device usb-redir,bus=usb.0,port=5,chardev=charredir4,id=ehci-redir4,bootindex=14 -chardev spicevmc,id=charredir5,name=usbredir
-device usb-redir,bus=usb.0,port=6,chardev=charredir5,id=ehci-redir5,bootindex=15
-device nec-usb-xhci,id=xhci,bus=pci.0,addr=0x19.0x0,p2=6,p3=6 -chardev spicevmc,id=charredir6,name=usbredir
-device usb-redir,bus=xhci.0,port=1,chardev=charredir6,id=xhci-redir0,bootindex=16 -chardev spicevmc,id=charredir7,name=usbredir
-device usb-redir,bus=xhci.0,port=2,chardev=charredir7,id=xhci-redir1,bootindex=17 -chardev spicevmc,id=charredir8,name=usbredir
-device usb-redir,bus=xhci.0,port=3,chardev=charredir8,id=xhci-redir2,bootindex=18 -chardev spicevmc,id=charredir9,name=usbredir
-device usb-redir,bus=xhci.0,port=4,chardev=charredir9,id=xhci-redir3,bootindex=19 -chardev spicevmc,id=charredir10,name=usbredir
-device usb-redir,bus=xhci.0,port=5,chardev=charredir10,id=xhci-redir4,bootindex=20 -chardev spicevmc,id=charredir11,name=usbredir
-device usb-redir,bus=xhci.0,port=6,chardev=charredir11,id=xhci-redir5,bootindex=21 -vga qxl -global qxl-vga.ram_size=134217728 -global qxl-vga.vram_size=134217728 -global qxl-vga.vgamem_mb=32 -no-hpet -k en-us -chardev socket,id=chardev_vhostblk0,path=/var/run/vs/vhost/vhost-blk-1384900388335-1376404350-0,reconnect=1,reconnect-retry=10 -chardev socket,id=chardev_vhostblk1,path=/var/run/vs/vhost/vhost-blk-1384900388335-1376404350-1,reconnect=1,reconnect-retry=10 -boot menu=on,splash-time=20000,ostype=windows,reboot-timeout=5000 -smp sockets=1,cores=8 -m 16384 -object memory-backend-file,id=mem-node0,size=16384M,mem-path=/dev/hugepages,share=on,host-nodes=0,policy=preferred -numa node,nodeid=0,memdev=mem-node0,cpus=0-7
-device pci-bridge,id=pci.2,chassis_nr=2,bus=pci.0,addr=0x1e
-device pci-bridge,id=pci.3,chassis_nr=3,bus=pci.0,addr=0x1f
-device pci-bridge,id=pci.1,chassis_nr=1,bus=pci.0,addr=0x6 -usb
-device usb-hub,id=reserved_usb_hub,bus=usb-bus.0,port=1 -drive file=/sf/data/7e3a8f8cdf74f2c0b002344bbd23d811/cn_windows_server_2016_x64_dvd_9327743.iso,if=none,id=drive-ide2,media=cdrom
-device ide-cd,bus=ide.1,unit=0,drive=drive-ide2,id=ide2,bootindex=200,serial=1384900388335-2
-device vhost-user-blk-pci,chardev=chardev_vhostblk0,id=vhostblk0,bus=pci.0,addr=0xa,bootindex=100
-device vhost-user-blk-pci,chardev=chardev_vhostblk1,id=vhostblk1,bus=pci.0,addr=0xb -netdev type=tap,id=net0,ifname=138490038833500
-device e1000,romfile=,mac=FE:FC:FE:BA:B0:EC,netdev=net0,bus=pci.0,addr=0x12,id=net0 -rtc driftfix=slew,clock=rt,base=localtime -global kvm-pit.lost_tick_policy=discard -global PIIX4_PM.disable_s3=1 -global PIIX4_PM.disable_s4=1 -chardev socket,path=/var/run/qemu-server/1384900388335.virtser,server,nowait,id=channelser
-device virtio-serial,max_ports=2,ioeventfd=off
-device virtserialport,chardev=channelser,name=channelser.virtserial0.0 -machine mem-merge=off -machine smm=off -uuid dff9444f-ab69-4211-b23b-e4c66c0b7a64 -smbios type=1,manufacturer=sangfor,product=acloud,version=1,serial=DFF9444F00 -smbios type=2,manufacturer=sangfor,product=acloud,version=1,serial=1384900388335 -cmdline-version vmx-3.14 -bios /sf/share/kvm/bios.bin -post 1384900388335

• iometer.icf

iometer.zip

Best regards,
York

[vrozenfe]

@york-king

Thanks a lot.
Let me ask QE to reproduce the issue.

Best,
Vadim.

[YanVugenfirer]

Reviewed