* [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio)
@ 2019-10-12 14:25 Emanuele Faranda
2019-10-12 14:35 ` [Bug 1847861] " Emanuele Faranda
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Emanuele Faranda @ 2019-10-12 14:25 UTC (permalink / raw)
To: qemu-devel
Public bug reported:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio on
windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by fio.
You can see that, when the stuttering occurs, the stardard deviation is
high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
** Affects: qemu
Importance: Undecided
Status: New
** Description changed:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio on
windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by fio.
You can see that, when the stuttering occurs, the stardard deviation is
high and the minimum bandwidth is way below the average.
+
+ Additional note: the bandwidth reported with `fio` on my linux host is
+ about 2x the one reported in the guest:
+
+ sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
+ --name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
+ --readwrite=randread
+
+ read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1847861
Title:
Guest stuttering under high disk IO (virtio)
Status in QEMU:
New
Bug description:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio
on windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by
fio. You can see that, when the stuttering occurs, the stardard
deviation is high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1847861/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug 1847861] Re: Guest stuttering under high disk IO (virtio)
2019-10-12 14:25 [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio) Emanuele Faranda
@ 2019-10-12 14:35 ` Emanuele Faranda
2019-10-12 14:44 ` Emanuele Faranda
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Emanuele Faranda @ 2019-10-12 14:35 UTC (permalink / raw)
To: qemu-devel
You can find my libvirt XML attached. Here is the full qemu command
(taken from the ps output):
/usr/bin/qemu-system-x86_64 -name guest=win10,debug-threads=on -S
-object
secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-7-win10
/master-key.aes -machine pc-q35-3.1,accel=kvm,usb=off,vmport=off,dump-
guest-core=off -cpu host,topoext=on,hv-time,hv-relaxed,hv-vapic,hv-
spinlocks=0x1fff -drive
file=/usr/share/ovmf/x64/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on
-drive
file=/var/lib/libvirt/qemu/nvram/win10_VARS.fd,if=pflash,format=raw,unit=1
-m 8192 -overcommit mem-lock=off -smp 16,sockets=1,cores=8,threads=2
-object iothread,id=iothread1 -mem-prealloc -mem-path
/dev/hugepages/libvirt/qemu/7-win10 -numa
node,nodeid=0,cpus=0-7,mem=4096 -numa node,nodeid=1,cpus=8-15,mem=4096
-uuid d1c03f35-3846-4b76-a139-b798b497b95c -display none -no-user-config
-nodefaults -chardev socket,id=charmonitor,fd=34,server,nowait -mon
chardev=charmonitor,id=monitor,mode=control -rtc
base=localtime,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-
hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global
ICH9-LPC.disable_s4=1 -boot strict=on -device pcie-root-
port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2
-device pcie-root-
port,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 -device pcie-
root-port,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 -device
pcie-root-port,port=0x13,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3
-device pcie-root-
port,port=0x14,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 -device pcie-
root-port,port=0x15,chassis=6,id=pci.6,bus=pcie.0,addr=0x2.0x5 -device
pcie-root-port,port=0x16,chassis=7,id=pci.7,bus=pcie.0,addr=0x2.0x6
-device pcie-root-
port,port=0x17,chassis=8,id=pci.8,bus=pcie.0,addr=0x2.0x7 -device pcie-
root-
port,port=0x18,chassis=9,id=pci.9,bus=pcie.0,multifunction=on,addr=0x3
-device pcie-root-
port,port=0x19,chassis=10,id=pci.10,bus=pcie.0,addr=0x3.0x1 -device
pcie-pci-bridge,id=pci.11,bus=pci.3,addr=0x0 -device qemu-
xhci,p2=15,p3=15,id=usb,bus=pci.2,addr=0x0 -device
lsi,id=scsi0,bus=pci.11,addr=0x1 -drive
file=/dev/nvme0n1p3,format=raw,if=none,id=drive-virtio-
disk0,cache=none,aio=threads -device virtio-blk-
pci,scsi=off,bus=pci.8,addr=0x0,drive=drive-virtio-disk0,id=virtio-
disk0,bootindex=1,write-cache=on -drive if=none,id=drive-
sata0-0-0,readonly=on -device ide-cd,bus=ide.0,drive=drive-
sata0-0-0,id=sata0-0-0 -netdev tap,fd=37,id=hostnet0,vhost=on,vhostfd=38
-device virtio-net-
pci,netdev=hostnet0,id=net0,mac=52:54:00:7c:10:fc,bus=pci.1,addr=0x0
-chardev pty,id=charserial0 -device isa-
serial,chardev=charserial0,id=serial0 -chardev
spicevmc,id=charredir0,name=usbredir -device usb-
redir,chardev=charredir0,id=redir0,bus=usb.0,port=2 -chardev
spicevmc,id=charredir1,name=usbredir -device usb-
redir,chardev=charredir1,id=redir1,bus=usb.0,port=3 -device vfio-
pci,host=41:00.0,id=hostdev0,bus=pci.4,addr=0x0 -device vfio-
pci,host=41:00.1,id=hostdev1,bus=pci.5,addr=0x0 -device virtio-balloon-
pci,id=balloon0,bus=pci.6,addr=0x0 -object input-
linux,id=mouse1,evdev=/dev/input/by-path/pci-0000:42:00.3-usb-0:3:1.0
-event-mouse -object input-linux,id=kbd1,evdev=/dev/input/by-
path/pci-0000:42:00.3-usb-0:4:1.0-event-kbd,grab_all=on,repeat=on
-sandbox
on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny
-msg timestamp=on
Additional note: the performance of fio in the linux host is about 2x
the one on the guest:
fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
** Attachment added: "win10.xml"
https://bugs.launchpad.net/qemu/+bug/1847861/+attachment/5296726/+files/win10.xml
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1847861
Title:
Guest stuttering under high disk IO (virtio)
Status in QEMU:
New
Bug description:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio
on windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by
fio. You can see that, when the stuttering occurs, the stardard
deviation is high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1847861/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug 1847861] Re: Guest stuttering under high disk IO (virtio)
2019-10-12 14:25 [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio) Emanuele Faranda
2019-10-12 14:35 ` [Bug 1847861] " Emanuele Faranda
@ 2019-10-12 14:44 ` Emanuele Faranda
2021-04-22 7:42 ` Thomas Huth
2021-06-22 4:18 ` Launchpad Bug Tracker
3 siblings, 0 replies; 5+ messages in thread
From: Emanuele Faranda @ 2019-10-12 14:44 UTC (permalink / raw)
To: qemu-devel
** Description changed:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio on
windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by fio.
You can see that, when the stuttering occurs, the stardard deviation is
high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
+
+ Moreover, during the fio tests on the guest I've noticed that the CPU
+ usage on the host is very high (around 450%) whereas on the guest is
+ only 10%
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1847861
Title:
Guest stuttering under high disk IO (virtio)
Status in QEMU:
New
Bug description:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio
on windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by
fio. You can see that, when the stuttering occurs, the stardard
deviation is high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
Moreover, during the fio tests on the guest I've noticed that the CPU
usage on the host is very high (around 450%) whereas on the guest is
only 10%
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1847861/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug 1847861] Re: Guest stuttering under high disk IO (virtio)
2019-10-12 14:25 [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio) Emanuele Faranda
2019-10-12 14:35 ` [Bug 1847861] " Emanuele Faranda
2019-10-12 14:44 ` Emanuele Faranda
@ 2021-04-22 7:42 ` Thomas Huth
2021-06-22 4:18 ` Launchpad Bug Tracker
3 siblings, 0 replies; 5+ messages in thread
From: Thomas Huth @ 2021-04-22 7:42 UTC (permalink / raw)
To: qemu-devel
The QEMU project is currently considering to move its bug tracking to
another system. For this we need to know which bugs are still valid
and which could be closed already. Thus we are setting older bugs to
"Incomplete" now.
If you still think this bug report here is valid, then please switch
the state back to "New" within the next 60 days, otherwise this report
will be marked as "Expired". Or please mark it as "Fix Released" if
the problem has been solved with a newer version of QEMU already.
Thank you and sorry for the inconvenience.
** Changed in: qemu
Status: New => Incomplete
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1847861
Title:
Guest stuttering under high disk IO (virtio)
Status in QEMU:
Incomplete
Bug description:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio
on windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by
fio. You can see that, when the stuttering occurs, the stardard
deviation is high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
Moreover, during the fio tests on the guest I've noticed that the CPU
usage on the host is very high (around 450%) whereas on the guest is
only 10%
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1847861/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug 1847861] Re: Guest stuttering under high disk IO (virtio)
2019-10-12 14:25 [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio) Emanuele Faranda
` (2 preceding siblings ...)
2021-04-22 7:42 ` Thomas Huth
@ 2021-06-22 4:18 ` Launchpad Bug Tracker
3 siblings, 0 replies; 5+ messages in thread
From: Launchpad Bug Tracker @ 2021-06-22 4:18 UTC (permalink / raw)
To: qemu-devel
[Expired for QEMU because there has been no activity for 60 days.]
** Changed in: qemu
Status: Incomplete => Expired
--
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https://bugs.launchpad.net/bugs/1847861
Title:
Guest stuttering under high disk IO (virtio)
Status in QEMU:
Expired
Bug description:
Performing io intensive tasks on virtualized Windows causes the system
to visually stutter. I can often reproduce the problem by running fio
on windows:
fio --randrepeat=1 --ioengine=windowsaio --direct=1 --gtod_reduce=1
--name=test --filename=\\.\PhysicalDrive0 --bs=4k --iodepth=128
--size=4G --readwrite=randread
While the fio command is running, moving the mouse pointer will be be
laggy. The stuttering does not appear with iodepth <= 32 . The
stuttering also manifests while playing games, the music and video
pauses for a fraction of second in a playable but disturbing way.
Here are my system specs:
Host OS: archlinux
Guest OS: Windows 10 Enterprise
qemu version: qemu-git 8:v4.1.0.r1378.g98b2e3c9ab-1 (from AUR, compiled with -march=native)
CPU: AMD Ryzen Threadripper 1900X 8-Core Processor
Huge Pages: vm.nr_hugepages=4128
Disk: nvme type=raw, io=threads bus=virtio
GPU (passthrough): Radeon RX 570
Here are some fio test results on my windows guest:
[size=512M,iodepth=1 -> min=30k,avg=31k,stddev=508]
[size=2G,iodepth=8 -> min=203k,avg=207k,stddev=2.3k]
[size=2G,iodepth=16 -> min=320k,avg=330k,stddev=4.3k]
[size=4G,iodepth=32 -> min=300k,avg=310k,stddev=4.8k]
[size=4G,iodepth=64 -> min=278k,avg=366k,stddev=68.6k] -> STUTTER
[size=4G,iodepth=64 -> min=358k,avg=428k,stddev=52.6k] -> STUTTER
[size=4G,iodepth=128 -> min=92k,avg=217k,stddev=185k] -> STUTTER
[size=4G,iodepth=128 -> min=241k,avg=257k,stddev=14k] -> same config as above, but no stuttering
The min and avg values are the bandwidth values reported in KB/s by
fio. You can see that, when the stuttering occurs, the stardard
deviation is high and the minimum bandwidth is way below the average.
Additional note: the bandwidth reported with `fio` on my linux host is
about 2x the one reported in the guest:
sudo fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1
--name=test --filename=/dev/nvme0n1 --bs=4k --iodepth=64 --size=512M
--readwrite=randread
read: IOPS=279k, BW=1092MiB/s (1145MB/s)(512MiB/469msec)
Moreover, during the fio tests on the guest I've noticed that the CPU
usage on the host is very high (around 450%) whereas on the guest is
only 10%
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1847861/+subscriptions
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-06-22 5:41 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-12 14:25 [Bug 1847861] [NEW] Guest stuttering under high disk IO (virtio) Emanuele Faranda
2019-10-12 14:35 ` [Bug 1847861] " Emanuele Faranda
2019-10-12 14:44 ` Emanuele Faranda
2021-04-22 7:42 ` Thomas Huth
2021-06-22 4:18 ` Launchpad Bug Tracker
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