Commit Graph

4 Commits (1847f260428012701c61f8f86b72b530d15c1db3)

Author SHA1 Message Date
Jordan Whited df6014f1d7
net/tstun,wgengine{/netstack/gro}: refactor and re-enable gVisor GRO for Linux (#13172)
In 2f27319baf we disabled GRO due to a
data race around concurrent calls to tstun.Wrapper.Write(). This commit
refactors GRO to be thread-safe, and re-enables it on Linux.

This refactor now carries a GRO type across tstun and netstack APIs
with a lifetime that is scoped to a single tstun.Wrapper.Write() call.

In 25f0a3fc8f we used build tags to
prevent importation of gVisor's GRO package on iOS as at the time we
believed it was contributing to additional memory usage on that
platform. It wasn't, so this commit simplifies and removes those
build tags.

Updates tailscale/corp#22353
Updates tailscale/corp#22125
Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
3 months ago
Jordan Whited 25f0a3fc8f
wgengine/netstack: use build tags to exclude gVisor GRO importation on iOS (#13015)
Updates tailscale/corp#22125

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Jordan Whited f0230ce0b5
go.mod,net/tstun,wgengine/netstack: implement gVisor TCP GRO for Linux (#12921)
This commit implements TCP GRO for packets being written to gVisor on
Linux. Windows support will follow later. The wireguard-go dependency is
updated in order to make use of newly exported IP checksum functions.
gVisor is updated in order to make use of newly exported
stack.PacketBuffer GRO logic.

TCP throughput towards gVisor, i.e. TUN write direction, is dramatically
improved as a result of this commit. Benchmarks show substantial
improvement, sometimes as high as 2x. High bandwidth-delay product
paths remain receive window limited, bottlenecked by gVisor's default
TCP receive socket buffer size. This will be addressed in a  follow-on
commit.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. There is roughly ~13us of round
trip latency between them.

The first result is from commit 57856fc without TCP GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  4.77 GBytes  4.10 Gbits/sec   20 sender
[  5]   0.00-10.00  sec  4.77 GBytes  4.10 Gbits/sec      receiver

The second result is from this commit with TCP GRO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  10.6 GBytes  9.14 Gbits/sec   20 sender
[  5]   0.00-10.00  sec  10.6 GBytes  9.14 Gbits/sec      receiver

Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago
Jordan Whited 7bc2ddaedc
go.mod,net/tstun,wgengine/netstack: implement gVisor TCP GSO for Linux (#12869)
This commit implements TCP GSO for packets being read from gVisor on
Linux. Windows support will follow later. The wireguard-go dependency is
updated in order to make use of newly exported GSO logic from its tun
package.

A new gVisor stack.LinkEndpoint implementation has been established
(linkEndpoint) that is loosely modeled after its predecessor
(channel.Endpoint). This new implementation supports GSO of monster TCP
segments up to 64K in size, whereas channel.Endpoint only supports up to
32K. linkEndpoint will also be required for GRO, which will be
implemented in a follow-on commit.

TCP throughput from gVisor, i.e. TUN read direction, is dramatically
improved as a result of this commit. Benchmarks show substantial
improvement through a wide range of RTT and loss conditions, sometimes
as high as 5x.

The iperf3 results below demonstrate the effect of this commit between
two Linux computers with i5-12400 CPUs. There is roughly ~13us of round
trip latency between them.

The first result is from commit 57856fc without TCP GSO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  2.51 GBytes  2.15 Gbits/sec  154 sender
[  5]   0.00-10.00  sec  2.49 GBytes  2.14 Gbits/sec      receiver

The second result is from this commit with TCP GSO.

Starting Test: protocol: TCP, 1 streams, 131072 byte blocks
- - - - - - - - - - - - - - - - - - - - - - - - -
Test Complete. Summary Results:
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  12.6 GBytes  10.8 Gbits/sec    6 sender
[  5]   0.00-10.00  sec  12.6 GBytes  10.8 Gbits/sec      receiver

Updates #6816

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 months ago