* [Qemu-devel] [Bug 597351] Re: Slow UDP performance with virtio device
2010-06-22 16:45 [Qemu-devel] [Bug 597351] [NEW] Slow UDP performance with virtio device Andy Ross
@ 2010-06-22 16:45 ` Andy Ross
2016-11-09 20:34 ` Thomas Huth
2017-01-09 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: Andy Ross @ 2010-06-22 16:45 UTC (permalink / raw)
To: qemu-devel
** Attachment added: "udp-pong.c"
http://launchpadlibrarian.net/50751155/udp-pong.c
--
Slow UDP performance with virtio device
https://bugs.launchpad.net/bugs/597351
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
Status in QEMU: New
Bug description:
I'm working on an app that is very sensitive to round-trip latency
between the guest and host, and qemu/kvm seems to be significantly
slower than it needs to be.
The attached program is a ping/pong over UDP. Call it with a single
argument to start a listener/echo server on that port. With three
arguments it becomes a counted "pinger" that will exit after a
specified number of round trips for performance measurements. For
example:
$ gcc -o udp-pong udp-pong.c
$ ./udp-pong 12345 & # start a listener on port 12345
$ time ./udp-pong 127.0.0.1 12345 1000000 # time a million round trips
When run on the loopback device on a single machine (true on the host
or within a guest), I get about 100k/s.
When run across a port forward using "user" networking on qemu (or
kvm, the performance is the same) and the default rtl8139 driver (both
the host and guest are Ubuntu Lucid), I get about 10k/s. This seems
very slow, but perhaps unavoidably so?
When run in the same configuration using the "virtio" driver, I get
only 2k/s. This is almost certainly a bug in the virtio driver, given
that it's a paravirtualized device that is 5x slower than the "slow"
hardware emulation.
I get no meaningful change in performance between kvm/qemu.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 597351] [NEW] Slow UDP performance with virtio device
@ 2010-06-22 16:45 Andy Ross
2010-06-22 16:45 ` [Qemu-devel] [Bug 597351] " Andy Ross
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Andy Ross @ 2010-06-22 16:45 UTC (permalink / raw)
To: qemu-devel
Public bug reported:
I'm working on an app that is very sensitive to round-trip latency
between the guest and host, and qemu/kvm seems to be significantly
slower than it needs to be.
The attached program is a ping/pong over UDP. Call it with a single
argument to start a listener/echo server on that port. With three
arguments it becomes a counted "pinger" that will exit after a
specified number of round trips for performance measurements. For
example:
$ gcc -o udp-pong udp-pong.c
$ ./udp-pong 12345 & # start a listener on port 12345
$ time ./udp-pong 127.0.0.1 12345 1000000 # time a million round trips
When run on the loopback device on a single machine (true on the host
or within a guest), I get about 100k/s.
When run across a port forward using "user" networking on qemu (or
kvm, the performance is the same) and the default rtl8139 driver (both
the host and guest are Ubuntu Lucid), I get about 10k/s. This seems
very slow, but perhaps unavoidably so?
When run in the same configuration using the "virtio" driver, I get
only 2k/s. This is almost certainly a bug in the virtio driver, given
that it's a paravirtualized device that is 5x slower than the "slow"
hardware emulation.
I get no meaningful change in performance between kvm/qemu.
** Affects: qemu
Importance: Undecided
Status: New
--
Slow UDP performance with virtio device
https://bugs.launchpad.net/bugs/597351
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
Status in QEMU: New
Bug description:
I'm working on an app that is very sensitive to round-trip latency
between the guest and host, and qemu/kvm seems to be significantly
slower than it needs to be.
The attached program is a ping/pong over UDP. Call it with a single
argument to start a listener/echo server on that port. With three
arguments it becomes a counted "pinger" that will exit after a
specified number of round trips for performance measurements. For
example:
$ gcc -o udp-pong udp-pong.c
$ ./udp-pong 12345 & # start a listener on port 12345
$ time ./udp-pong 127.0.0.1 12345 1000000 # time a million round trips
When run on the loopback device on a single machine (true on the host
or within a guest), I get about 100k/s.
When run across a port forward using "user" networking on qemu (or
kvm, the performance is the same) and the default rtl8139 driver (both
the host and guest are Ubuntu Lucid), I get about 10k/s. This seems
very slow, but perhaps unavoidably so?
When run in the same configuration using the "virtio" driver, I get
only 2k/s. This is almost certainly a bug in the virtio driver, given
that it's a paravirtualized device that is 5x slower than the "slow"
hardware emulation.
I get no meaningful change in performance between kvm/qemu.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 597351] Re: Slow UDP performance with virtio device
2010-06-22 16:45 [Qemu-devel] [Bug 597351] [NEW] Slow UDP performance with virtio device Andy Ross
2010-06-22 16:45 ` [Qemu-devel] [Bug 597351] " Andy Ross
@ 2016-11-09 20:34 ` Thomas Huth
2017-01-09 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: Thomas Huth @ 2016-11-09 20:34 UTC (permalink / raw)
To: qemu-devel
Triaging old bug tickets ... can you still reproduce this issue with the
latest version of QEMU? Have you already tried vhost?
** 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/597351
Title:
Slow UDP performance with virtio device
Status in QEMU:
Incomplete
Bug description:
I'm working on an app that is very sensitive to round-trip latency
between the guest and host, and qemu/kvm seems to be significantly
slower than it needs to be.
The attached program is a ping/pong over UDP. Call it with a single
argument to start a listener/echo server on that port. With three
arguments it becomes a counted "pinger" that will exit after a
specified number of round trips for performance measurements. For
example:
$ gcc -o udp-pong udp-pong.c
$ ./udp-pong 12345 & # start a listener on port 12345
$ time ./udp-pong 127.0.0.1 12345 1000000 # time a million round trips
When run on the loopback device on a single machine (true on the host
or within a guest), I get about 100k/s.
When run across a port forward using "user" networking on qemu (or
kvm, the performance is the same) and the default rtl8139 driver (both
the host and guest are Ubuntu Lucid), I get about 10k/s. This seems
very slow, but perhaps unavoidably so?
When run in the same configuration using the "virtio" driver, I get
only 2k/s. This is almost certainly a bug in the virtio driver, given
that it's a paravirtualized device that is 5x slower than the "slow"
hardware emulation.
I get no meaningful change in performance between kvm/qemu.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/597351/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Qemu-devel] [Bug 597351] Re: Slow UDP performance with virtio device
2010-06-22 16:45 [Qemu-devel] [Bug 597351] [NEW] Slow UDP performance with virtio device Andy Ross
2010-06-22 16:45 ` [Qemu-devel] [Bug 597351] " Andy Ross
2016-11-09 20:34 ` Thomas Huth
@ 2017-01-09 4:17 ` Launchpad Bug Tracker
2 siblings, 0 replies; 4+ messages in thread
From: Launchpad Bug Tracker @ 2017-01-09 4:17 UTC (permalink / raw)
To: qemu-devel
[Expired for QEMU because there has been no activity for 60 days.]
** Changed in: qemu
Status: Incomplete => Expired
--
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/597351
Title:
Slow UDP performance with virtio device
Status in QEMU:
Expired
Bug description:
I'm working on an app that is very sensitive to round-trip latency
between the guest and host, and qemu/kvm seems to be significantly
slower than it needs to be.
The attached program is a ping/pong over UDP. Call it with a single
argument to start a listener/echo server on that port. With three
arguments it becomes a counted "pinger" that will exit after a
specified number of round trips for performance measurements. For
example:
$ gcc -o udp-pong udp-pong.c
$ ./udp-pong 12345 & # start a listener on port 12345
$ time ./udp-pong 127.0.0.1 12345 1000000 # time a million round trips
When run on the loopback device on a single machine (true on the host
or within a guest), I get about 100k/s.
When run across a port forward using "user" networking on qemu (or
kvm, the performance is the same) and the default rtl8139 driver (both
the host and guest are Ubuntu Lucid), I get about 10k/s. This seems
very slow, but perhaps unavoidably so?
When run in the same configuration using the "virtio" driver, I get
only 2k/s. This is almost certainly a bug in the virtio driver, given
that it's a paravirtualized device that is 5x slower than the "slow"
hardware emulation.
I get no meaningful change in performance between kvm/qemu.
To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/597351/+subscriptions
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-01-09 4:30 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2010-06-22 16:45 [Qemu-devel] [Bug 597351] [NEW] Slow UDP performance with virtio device Andy Ross
2010-06-22 16:45 ` [Qemu-devel] [Bug 597351] " Andy Ross
2016-11-09 20:34 ` Thomas Huth
2017-01-09 4:17 ` Launchpad Bug Tracker
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