mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 08:44:21 +08:00
f744c4bb5c
Toshiaki Makita says:
====================
vhost_net: Avoid vq kicks during busyloop
Under heavy load vhost tx busypoll tend not to suppress vq kicks, which
causes poor guest tx performance. The detailed scenario is described in
commitlog of patch 2.
Rx seems not to have that serious problem, but for consistency I made a
similar change on rx to avoid rx wakeups (patch 3).
Additionary patch 4 is to avoid rx kicks under heavy load during
busypoll.
Tx performance is greatly improved by this change. I don't see notable
performance change on rx with this series though.
Performance numbers (tx):
- Bulk transfer from guest to external physical server.
[Guest]->vhost_net->tap--(XDP_REDIRECT)-->i40e --(wire)--> [Server]
- Set 10us busypoll.
- Guest disables checksum and TSO because of host XDP.
- Measured single flow Mbps by netperf, and kicks by perf kvm stat
(EPT_MISCONFIG event).
Before After
Mbps kicks/s Mbps kicks/s
UDP_STREAM 1472byte 247758 27
Send 3645.37 6958.10
Recv 3588.56 6958.10
1byte 9865 37
Send 4.34 5.43
Recv 4.17 5.26
TCP_STREAM 8801.03 45794 9592.77 2884
v2:
- Split patches into 3 parts (renaming variables, tx-kick fix, rx-wakeup
fix).
- Avoid rx-kicks too (patch 4).
- Don't memorize endtime as it is not needed for now.
====================
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.