Brad FitzpatrickandBrad Fitzpatrick
db017d3b12
control/controlclient: remove quadratic allocs in mapSession
The mapSession code was previously quadratic: N clients in a netmap
send updates proportional to N and then for each, we do N units of
work. This removes most of that "N units of work" per update. There's
still a netmap-sized slice allocation per update (that's #8963), but
that's it.
Bit more efficient now, especially with larger netmaps:
│ before │ after │
│ sec/op │ sec/op vs base │
MapSessionDelta/size_10-8 47.935µ ± 3% 1.232µ ± 2% -97.43% (p=0.000 n=10)
MapSessionDelta/size_100-8 79.950µ ± 3% 1.642µ ± 2% -97.95% (p=0.000 n=10)
MapSessionDelta/size_1000-8 355.747µ ± 10% 4.400µ ± 1% -98.76% (p=0.000 n=10)
MapSessionDelta/size_10000-8 3079.71µ ± 3% 27.89µ ± 3% -99.09% (p=0.000 n=10)
geomean 254.6µ 3.969µ -98.44%
│ before │ after │
│ B/op │ B/op vs base │
MapSessionDelta/size_10-8 9.651Ki ± 0% 2.395Ki ± 0% -75.19% (p=0.000 n=10)
MapSessionDelta/size_100-8 83.097Ki ± 0% 3.192Ki ± 0% -96.16% (p=0.000 n=10)
MapSessionDelta/size_1000-8 800.25Ki ± 0% 10.32Ki ± 0% -98.71% (p=0.000 n=10)
MapSessionDelta/size_10000-8 7896.04Ki ± 0% 82.32Ki ± 0% -98.96% (p=0.000 n=10)
geomean 266.8Ki 8.977Ki -96.64%
│ before │ after │
│ allocs/op │ allocs/op vs base │
MapSessionDelta/size_10-8 72.00 ± 0% 20.00 ± 0% -72.22% (p=0.000 n=10)
MapSessionDelta/size_100-8 523.00 ± 0% 20.00 ± 0% -96.18% (p=0.000 n=10)
MapSessionDelta/size_1000-8 5024.00 ± 0% 20.00 ± 0% -99.60% (p=0.000 n=10)
MapSessionDelta/size_10000-8 50024.00 ± 0% 20.00 ± 0% -99.96% (p=0.000 n=10)
geomean 1.754k 20.00 -98.86%
Updates #1909
Change-Id: I41ee29358a5521ed762216a76d4cc5b0d16e46ac
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2023-08-22 08:59:57 -07:00
..
2023-04-17 18:38:24 -04:00
2023-08-22 08:59:57 -07:00
2023-08-09 15:03:22 -07:00
2023-01-27 15:36:29 -08:00