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![]() virtio-net-pci does not enable ioeventfd for historical reasons (and nobody ever checked whether it should be revisited). Note that other backends do enable ioeventfd for virtio-net. However, it has a major effect on performance. On Windows, throughput is _multiplied_ by 2 or 3 on TCP_STREAM (on small packets it is "only" a 30% improvement) and a little less so on TCP_MAERTS albeit still very much statistically significant. Latency also has a single digit improvement. This is not visible when using vhost, which forces ioeventfd=on, but it is substantial without vhost. In addition, also on Windows and with the RHEL 7.3 kernel, APICv seems to slow down virtio-net performance a bit, but the penalty with this patch goes from -25% to -7%. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> |
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.. | ||
Makefile.objs | ||
trace-events | ||
vhost-backend.c | ||
vhost-user.c | ||
vhost-vsock.c | ||
vhost.c | ||
virtio-balloon.c | ||
virtio-bus.c | ||
virtio-crypto-pci.c | ||
virtio-crypto.c | ||
virtio-mmio.c | ||
virtio-pci.c | ||
virtio-pci.h | ||
virtio-rng.c | ||
virtio.c |