Alex Valiushko 330a17b7d7 net/batching: use vectored writes on Linux (#19054) ...

On Linux batching.Conn will now write a vector of
coalesced buffers via sendmmsg(2) instead of copying
fragments into a single buffer.

Scatter-gather I/O has been available on Linux since the
earliest days (reworked in 2.6.24). Kernel passes fragments
to the driver if it supports it, otherwise linearizes
upon receiving the data.

Removing the copy overhead from userspace yields up to 4-5%
packet and bitrate improvement on Linux with GSO enabled:
46Gb/s 4.4m pps vs 44Gb/s 4.2m pps w/32 Peer Relay client flows.

Updates tailscale/corp#36989


Change-Id: Idb2248d0964fb011f1c8f957ca555eab6a6a6964

Signed-off-by: Alex Valiushko <alexvaliushko@tailscale.com>

2026-03-25 16:38:54 -07:00

..

conn_default.go

net/{batching,udprelay},wgengine/magicsock: add SO_RXQ_OVFL clientmetrics

2026-03-13 14:27:03 -07:00

conn_linux_test.go

net/batching: use vectored writes on Linux (#19054)

2026-03-25 16:38:54 -07:00

conn_linux.go

net/batching: use vectored writes on Linux (#19054)

2026-03-25 16:38:54 -07:00

conn.go

net/batching: clarify & simplify single packet read limitations

2026-03-11 10:25:58 -07:00