On Wed, Oct 20, 2010 at 02:24:52PM +0530, Krishna Kumar wrote:
> Following set of patches implement transmit MQ in virtio-net. Also
> included is the user qemu changes. MQ is disabled by default unless
> qemu specifies it.
Hi Krishna,
I have a few questions about the results below:
1. Are the (%) comparisons between non-mq and mq virtio?
2. Was UDP or TCP used?
3. What was the transmit size (-m option to netperf)?
Also, I'm interested to know what the status of these patches is.
Are you planing a fresh series?
>
> Changes from rev2:
> ------------------
> 1. Define (in virtio_net.h) the maximum send txqs; and use in
> virtio-net and vhost-net.
> 2. vi->sq[i] is allocated individually, resulting in cache line
> aligned sq[0] to sq[n]. Another option was to define
> 'send_queue' as:
> struct send_queue {
> struct virtqueue *svq;
> struct scatterlist tx_sg[MAX_SKB_FRAGS + 2];
> } ____cacheline_aligned_in_smp;
> and to statically allocate 'VIRTIO_MAX_SQ' of those. I hope
> the submitted method is preferable.
> 3. Changed vhost model such that vhost[0] handles RX and vhost[1-MAX]
> handles TX[0-n].
> 4. Further change TX handling such that vhost[0] handles both RX/TX
> for single stream case.
>
> Enabling MQ on virtio:
> -----------------------
> When following options are passed to qemu:
> - smp > 1
> - vhost=on
> - mq=on (new option, default:off)
> then #txqueues = #cpus. The #txqueues can be changed by using an
> optional 'numtxqs' option. e.g. for a smp=4 guest:
> vhost=on -> #txqueues = 1
> vhost=on,mq=on -> #txqueues = 4
> vhost=on,mq=on,numtxqs=2 -> #txqueues = 2
> vhost=on,mq=on,numtxqs=8 -> #txqueues = 8
>
>
> Performance (guest -> local host):
> -----------------------------------
> System configuration:
> Host: 8 Intel Xeon, 8 GB memory
> Guest: 4 cpus, 2 GB memory
> Test: Each test case runs for 60 secs, sum over three runs (except
> when number of netperf sessions is 1, which has 10 runs of 12 secs
> each). No tuning (default netperf) other than taskset vhost's to
> cpus 0-3. numtxqs=32 gave the best results though the guest had
> only 4 vcpus (I haven't tried beyond that).
>
> ______________ numtxqs=2, vhosts=3 ____________________
> #sessions BW% CPU% RCPU% SD% RSD%
> ________________________________________________________
> 1 4.46 -1.96 .19 -12.50 -6.06
> 2 4.93 -1.16 2.10 0 -2.38
> 4 46.17 64.77 33.72 19.51 -2.48
> 8 47.89 70.00 36.23 41.46 13.35
> 16 48.97 80.44 40.67 21.11 -5.46
> 24 49.03 78.78 41.22 20.51 -4.78
> 32 51.11 77.15 42.42 15.81 -6.87
> 40 51.60 71.65 42.43 9.75 -8.94
> 48 50.10 69.55 42.85 11.80 -5.81
> 64 46.24 68.42 42.67 14.18 -3.28
> 80 46.37 63.13 41.62 7.43 -6.73
> 96 46.40 63.31 42.20 9.36 -4.78
> 128 50.43 62.79 42.16 13.11 -1.23
> ________________________________________________________
> BW: 37.2%, CPU/RCPU: 66.3%,41.6%, SD/RSD: 11.5%,-3.7%
>
> ______________ numtxqs=8, vhosts=5 ____________________
> #sessions BW% CPU% RCPU% SD% RSD%
> ________________________________________________________
> 1 -.76 -1.56 2.33 0 3.03
> 2 17.41 11.11 11.41 0 -4.76
> 4 42.12 55.11 30.20 19.51 .62
> 8 54.69 80.00 39.22 24.39 -3.88
> 16 54.77 81.62 40.89 20.34 -6.58
> 24 54.66 79.68 41.57 15.49 -8.99
> 32 54.92 76.82 41.79 17.59 -5.70
> 40 51.79 68.56 40.53 15.31 -3.87
> 48 51.72 66.40 40.84 9.72 -7.13
> 64 51.11 63.94 41.10 5.93 -8.82
> 80 46.51 59.50 39.80 9.33 -4.18
> 96 47.72 57.75 39.84 4.20 -7.62
> 128 54.35 58.95 40.66 3.24 -8.63
> ________________________________________________________
> BW: 38.9%, CPU/RCPU: 63.0%,40.1%, SD/RSD: 6.0%,-7.4%
>
> ______________ numtxqs=16, vhosts=5 ___________________
> #sessions BW% CPU% RCPU% SD% RSD%
> ________________________________________________________
> 1 -1.43 -3.52 1.55 0 3.03
> 2 33.09 21.63 20.12 -10.00 -9.52
> 4 67.17 94.60 44.28 19.51 -11.80
> 8 75.72 108.14 49.15 25.00 -10.71
> 16 80.34 101.77 52.94 25.93 -4.49
> 24 70.84 93.12 43.62 27.63 -5.03
> 32 69.01 94.16 47.33 29.68 -1.51
> 40 58.56 63.47 25.91 -3.92 -25.85
> 48 61.16 74.70 34.88 .89 -22.08
> 64 54.37 69.09 26.80 -6.68 -30.04
> 80 36.22 22.73 -2.97 -8.25 -27.23
> 96 41.51 50.59 13.24 9.84 -16.77
> 128 48.98 38.15 6.41 -.33 -22.80
> ________________________________________________________
> BW: 46.2%, CPU/RCPU: 55.2%,18.8%, SD/RSD: 1.2%,-22.0%
>
> ______________ numtxqs=32, vhosts=5 ___________________
> # BW% CPU% RCPU% SD% RSD%
> ________________________________________________________
> 1 7.62 -38.03 -26.26 -50.00 -33.33
> 2 28.95 20.46 21.62 0 -7.14
> 4 84.05 60.79 45.74 -2.43 -12.42
> 8 86.43 79.57 50.32 15.85 -3.10
> 16 88.63 99.48 58.17 9.47 -13.10
> 24 74.65 80.87 41.99 -1.81 -22.89
> 32 63.86 59.21 23.58 -18.13 -36.37
> 40 64.79 60.53 22.23 -15.77 -35.84
> 48 49.68 26.93 .51 -36.40 -49.61
> 64 54.69 36.50 5.41 -26.59 -43.23
> 80 45.06 12.72 -13.25 -37.79 -52.08
> 96 40.21 -3.16 -24.53 -39.92 -52.97
> 128 36.33 -33.19 -43.66 -5.68 -20.49
> ________________________________________________________
> BW: 49.3%, CPU/RCPU: 15.5%,-8.2%, SD/RSD: -22.2%,-37.0%
>
>
> Signed-off-by: Krishna Kumar <krkumar2@xxxxxxxxxx>
> ---
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
