2 commits

Author	SHA1	Message	Date
Tu Dinh Ngoc	75d6c67a67	tun: use add-with-carry in checksumNoFold() ... Use parallel summation with native byte order per RFC 1071. add-with-carry operation is used to add 4 words per operation. Byteswap is performed before and after checksumming for compatibility with old `checksumNoFold()`. With this we get a 30-80% speedup in `checksum()` depending on packet sizes. Add unit tests with comparison to a per-word implementation. **Intel(R) Xeon(R) Silver 4210R CPU @ 2.40GHz** | Size | OldTime | NewTime | Speedup | |------|---------|---------|----------| | 64 | 12.64 | 9.183 | 1.376456 | | 128 | 18.52 | 12.72 | 1.455975 | | 256 | 31.01 | 18.13 | 1.710425 | | 512 | 54.46 | 29.03 | 1.87599 | | 1024 | 102 | 52.2 | 1.954023 | | 1500 | 146.8 | 81.36 | 1.804326 | | 2048 | 196.9 | 102.5 | 1.920976 | | 4096 | 389.8 | 200.8 | 1.941235 | | 8192 | 767.3 | 413.3 | 1.856521 | | 9000 | 851.7 | 448.8 | 1.897727 | | 9001 | 854.8 | 451.9 | 1.891569 | **AMD EPYC 7352 24-Core Processor** | Size | OldTime | NewTime | Speedup | |------|---------|---------|----------| | 64 | 9.159 | 6.949 | 1.318031 | | 128 | 13.59 | 10.59 | 1.283286 | | 256 | 22.37 | 14.91 | 1.500335 | | 512 | 41.42 | 24.22 | 1.710157 | | 1024 | 81.59 | 45.05 | 1.811099 | | 1500 | 120.4 | 68.35 | 1.761522 | | 2048 | 162.8 | 90.14 | 1.806079 | | 4096 | 321.4 | 180.3 | 1.782585 | | 8192 | 650.4 | 360.8 | 1.802661 | | 9000 | 706.3 | 398.1 | 1.774177 | | 9001 | 712.4 | 398.2 | 1.789051 | Signed-off-by: Tu Dinh Ngoc <dinhngoc.tu@irit.fr> [Jason: simplified and cleaned up unit tests] Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>	2025-06-23 14:26:25 -06:00
Jordan Whited	895d6c23cd	tun: unwind summing loop in checksumNoFold() ... $ benchstat old.txt new.txt goos: linux goarch: amd64 pkg: golang.zx2c4.com/wireguard/tun cpu: 12th Gen Intel(R) Core(TM) i5-12400 │ old.txt │ new.txt │ │ sec/op │ sec/op vs base │ Checksum/64-12 10.670n ± 2% 4.769n ± 0% -55.30% (p=0.000 n=10) Checksum/128-12 19.665n ± 2% 8.032n ± 0% -59.16% (p=0.000 n=10) Checksum/256-12 37.68n ± 1% 16.06n ± 0% -57.37% (p=0.000 n=10) Checksum/512-12 76.61n ± 3% 32.13n ± 0% -58.06% (p=0.000 n=10) Checksum/1024-12 160.55n ± 4% 64.25n ± 0% -59.98% (p=0.000 n=10) Checksum/1500-12 231.05n ± 7% 94.12n ± 0% -59.26% (p=0.000 n=10) Checksum/2048-12 309.5n ± 3% 128.5n ± 0% -58.48% (p=0.000 n=10) Checksum/4096-12 603.8n ± 4% 257.2n ± 0% -57.41% (p=0.000 n=10) Checksum/8192-12 1185.0n ± 3% 515.5n ± 0% -56.50% (p=0.000 n=10) Checksum/9000-12 1328.5n ± 5% 564.8n ± 0% -57.49% (p=0.000 n=10) Checksum/9001-12 1340.5n ± 3% 564.8n ± 0% -57.87% (p=0.000 n=10) geomean 185.3n 77.99n -57.92% Reviewed-by: Adrian Dewhurst <adrian@tailscale.com> Signed-off-by: Jordan Whited <jordan@tailscale.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>	2023-10-10 15:07:36 +02:00