Now vsock only support send/receive small packet, it can't achieve
high performance. As previous discussed with Jason Wang, I revisit the
idea of vhost-net about mergeable rx buffer and implement the mergeable
rx buffer in vhost-vsock, it can allow big packet to be scattered in
into different buffers and improve performance obviously.
This series of patches mainly did three things：
- mergeable buffer implementation
- increase the max send pkt size
- add used and signal guest in a batch
And I write a tool to test the vhost-vsock performance, mainly send big
packet(64K) included guest->Host and Host->Guest. I test performance
independently and the result as follows:
Before performance:
Single socket Multiple sockets(Max Bandwidth)
Guest->Host ~400MB/s ~480MB/s
Host->Guest ~1450MB/s ~1600MB/s
After performance only use implement mergeable rx buffer:
Single socket Multiple sockets(Max Bandwidth)
Guest->Host ~400MB/s ~480MB/s
Host->Guest ~1280MB/s ~1350MB/s
In this case, max send pkt size is still limited to 4K, so Host->Guest
performance will worse than before.
After performance increase the max send pkt size to 64K:
Single socket Multiple sockets(Max Bandwidth)
Guest->Host ~1700MB/s ~2900MB/s
Host->Guest ~1500MB/s ~2440MB/s
After performance all patches are used:
Single socket Multiple sockets(Max Bandwidth)
Guest->Host ~1700MB/s ~2900MB/s
Host->Guest ~1700MB/s ~2900MB/s
>From the test results, the performance is improved obviously, and guest
memory will not be wasted.
In addition, in order to support mergeable rx buffer in virtio-vsock,
we need to add a qemu patch to support parse feature.
---
v1 -> v2:
* Addressed comments from Jason Wang.
* Add performance test result independently.
* Use Skb_page_frag_refill() which can use high order page and reduce
the stress of page allocator.
* Still use fixed size(PAGE_SIZE) to fill rx buffer, because too small
size can't fill one full packet, we only 128 vq num now.
* Use iovec to replace buf in struct virtio_vsock_pkt, keep tx and rx
consistency.
* Add virtio_transport ops to get max pkt len, in order to be compatible
with old version.
---
Yiwen Jiang (5):
VSOCK: support fill mergeable rx buffer in guest
VSOCK: support fill data to mergeable rx buffer in host
VSOCK: support receive mergeable rx buffer in guest
VSOCK: increase send pkt len in mergeable mode to improve performance
VSOCK: batch sending rx buffer to increase bandwidth
drivers/vhost/vsock.c | 183 ++++++++++++++++++++-----
include/linux/virtio_vsock.h | 13 +-
include/uapi/linux/virtio_vsock.h | 5 +
net/vmw_vsock/virtio_transport.c | 229 +++++++++++++++++++++++++++-----
net/vmw_vsock/virtio_transport_common.c | 66 ++++++---
5 files changed, 411 insertions(+), 85 deletions(-)
--
1.8.3.1
