To get the benefit of this optimization requires help from the Go toolchain.
The changes are upstream at https://golang.org/cl/320929,
and have been pulled into the Tailscale fork at
728ecc58fd.
It also requires building with the build tag tailscale_go.
name old time/op new time/op delta
Hash-8 14.0µs ± 0% 13.6µs ± 0% -2.88% (p=0.008 n=5+5)
HashMapAcyclic-8 24.3µs ± 1% 21.2µs ± 1% -12.47% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
Hash-8 2.16kB ± 0% 1.58kB ± 0% -27.01% (p=0.008 n=5+5)
HashMapAcyclic-8 2.53kB ± 0% 0.15kB ± 0% -93.99% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Hash-8 77.0 ± 0% 49.0 ± 0% -36.36% (p=0.008 n=5+5)
HashMapAcyclic-8 202 ± 0% 4 ± 0% -98.02% (p=0.008 n=5+5)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
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