Brad Fitzpatrick
6b729795c3
Replace the process-global Server.mu lookup in the packet send hot path
with a global hashtriemap mirror of local clientSet entries. The
authoritative clients map remains guarded by Server.mu; clientsAtomic is
only a lock-free fast path for active local clients.
Misses, stale inactive client sets, duplicate accounting, and mesh
forwarding still fall back to lookupDestUncached. This avoids taking
Server.mu for the common local active-client send path, at the cost of
adding one global concurrent map that mirrors Server.clients for local
peers.
The benchmark uses four destination peers. The before run sets
TS_DEBUG_DERP_DISABLE_PEER_HASHTRIE=true to force the old mutex lookup
path; the after run uses the hashtrie fast path.
goos: linux
goarch: amd64
pkg: tailscale.com/derp/derpserver
cpu: Intel(R) Xeon(R) 6975P-C
│ before │ after │
│ sec/op │ sec/op vs base │
LookupDestHashTrie-16 176.050n ± 1% 1.904n ± 6% -98.92% (p=0.000 n=10)
│ before │ after │
│ B/op │ B/op vs base │
LookupDestHashTrie-16 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹
¹ all samples are equal
│ before │ after │
│ allocs/op │ allocs/op vs base │
LookupDestHashTrie-16 0.000 ± 0% 0.000 ± 0% ~ (p=1.000 n=10) ¹
¹ all samples are equal
Updates #3560 (very indirectly, historically)
Updates #19713 (as an alternative to that PR)
Change-Id: Ifb72e5c9854ad00e938cd24c6ab9c27312f297e8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.26. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.