Avoid splitting fields in the common case. Field splitting was 84% of
the overall CPU.
name old time/op new time/op delta
ParsePorts-6 33.3ms ± 2% 6.3ms ± 4% -80.97% (p=0.000 n=9+10)
name old alloc/op new alloc/op delta
ParsePorts-6 520B ±79% 408B ± 0% -21.49% (p=0.046 n=10+8)
name old allocs/op new allocs/op delta
ParsePorts-6 7.00 ± 0% 7.00 ± 0% ~ (all equal)
Updates tailscale/corp#2566
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Notably, it no longer allocates proportional to the number of open
sockets on the machine. Any alloc reduction numbers are a little
contrived with such a reduction but e.g. on a machine with 50,000
connections open:
name old time/op new time/op delta
ParsePorts-6 57.7ms ± 6% 32.8ms ± 3% -43.04% (p=0.000 n=9+10)
name old alloc/op new alloc/op delta
ParsePorts-6 24.0MB ± 0% 0.0MB ± 0% -100.00% (p=0.000 n=10+9)
name old allocs/op new allocs/op delta
ParsePorts-6 100k ± 0% 0k ± 0% -99.99% (p=0.000 n=10+10)
Updates tailscale/corp#2566
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is important because some of those v6 sockets are actually
dual-stacked sockets, so this is our only chance of discovering
some services.
Fixes#1443.
Signed-off-by: David Anderson <danderson@tailscale.com>
This could happen when a process disappeared while we were reading its
file descriptor list.
I was able to replicate the problem by running this in another
terminal:
while :; do for i in $(seq 10); do
/bin/true & done >&/dev/null; wait >&/dev/null;
done
And then running the portlist tests thousands of times.
Fixes#339.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
staticcheck used to fail on macOS (and presumably windows) due to a
variable declared in a common package that was only used by the Linux
build, which would prevent `redo pr` from passing on Mac. Moved variable
declaration from the common file to the Linux-specific one to resolve
the compiler complaint.
Signed-off-by: Wendi Yu <wendi.yu@yahoo.ca>
I noticed portlist when looking at some profiles and hadn't looked at
the code much before. This is a first pass over it. It allocates a
fair bit. More love remains, but this does a bit:
name old time/op new time/op delta
GetList-8 9.92ms ± 8% 9.64ms ±12% ~ (p=0.247 n=10+10)
name old alloc/op new alloc/op delta
GetList-8 931kB ± 0% 869kB ± 0% -6.70% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
GetList-8 4.59k ± 0% 3.69k ± 1% -19.71% (p=0.000 n=10+10)
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
