Re: [PATCH v2 2/2] virtio-ring: Allocate indirect buffers from cache when possible
From: Sasha Levin <hidden>
Date: 2012-08-29 15:02:37
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lkml, virtualization
On 08/29/2012 01:07 PM, Michael S. Tsirkin wrote:
On Tue, Aug 28, 2012 at 03:35:00PM +0200, Sasha Levin wrote:quoted
On 08/28/2012 03:20 PM, Michael S. Tsirkin wrote:quoted
On Tue, Aug 28, 2012 at 03:04:03PM +0200, Sasha Levin wrote:quoted
Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors and allocate them using a simple kmalloc(). This patch adds a cache which will allow indirect buffers under a configurable size to be allocated from that cache instead. Signed-off-by: Sasha Levin <redacted>I imagine this helps performance? Any numbers?I ran benchmarks on the original RFC, I've re-tested it now and got similar numbers to the original ones (virtio-net using vhost-net, thresh=16): Before: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 4512.12 After: Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 5399.18 Thanks, SashaThis is with both patches 1 + 2? Sorry could you please also test what happens if you apply - just patch 1 - just patch 2 Thanks!
Sure thing! I've also re-ran it on a IBM server type host instead of my laptop. Here are the results: Vanilla kernel: MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.1 () port 0 AF_INET enable_enobufs failed: getprotobyname Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 7922.72 Patch 1, with threshold=16: MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.1 () port 0 AF_INET enable_enobufs failed: getprotobyname Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 8415.07 Patch 2: MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.33.1 () port 0 AF_INET enable_enobufs failed: getprotobyname Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 8931.05 Note that these are simple tests with netperf listening on one end and a simple 'netperf -H [host]' within the guest. If there are other tests which may be interesting please let me know. Thanks, Sasha