crypto/tls: consider less allocations for Conn.Read

[TriAnMan]

What version of Go are you using (go version)?

$ go version
go version go1.17.6 darwin/amd64

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/anton/Library/Caches/go-build"
GOENV="/Users/anton/Library/Application Support/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOINSECURE=""
GOMODCACHE="/Users/anton/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="darwin"
GOPATH="/Users/anton/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/usr/local/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/darwin_amd64"
GOVCS=""
GOVERSION="go1.17.6"
GCCGO="gccgo"
AR="ar"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD="/dev/null"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -arch x86_64 -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/3_/brw14zgj1sd1x1hnnz4p02tm0000gn/T/go-build266993821=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I'm running a websocket client application consuming lots of short messages from its established websocket connection.

What did you expect to see?

I would like to have no allocations for Conn.Read calls.

What did you see instead?

Each call of Conn.Read allocates one atLeastReader while going through Conn.readFromUntil.

There also were some redundant allocations fixed in #50657.
Combining #50657 with the patch I'm currently doing makes Conn.Read have zero allocations.

[TriAnMan]

The bechmarks of #53143 against release-branch.go1.17 show considerable improvement in performance:

1.17 bench

name                                     old time/op    new time/op    delta
Throughput/MaxPacket/1MB/TLSv12-12         3.93ms ± 3%    3.95ms ± 4%     ~     (p=0.305 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12         4.18ms ± 2%    4.20ms ± 2%     ~     (p=0.375 n=13+14)
Throughput/MaxPacket/2MB/TLSv12-12         7.23ms ± 3%    7.15ms ± 3%   -1.18%  (p=0.037 n=13+15)
Throughput/MaxPacket/2MB/TLSv13-12         7.43ms ± 6%    7.16ms ± 2%   -3.54%  (p=0.000 n=14+15)
Throughput/MaxPacket/4MB/TLSv12-12         13.7ms ± 7%    12.9ms ± 1%   -5.85%  (p=0.000 n=15+12)
Throughput/MaxPacket/4MB/TLSv13-12         14.3ms ± 8%    13.1ms ± 1%   -8.58%  (p=0.000 n=15+13)
Throughput/MaxPacket/8MB/TLSv12-12         25.2ms ± 2%    24.6ms ± 1%   -2.63%  (p=0.000 n=14+14)
Throughput/MaxPacket/8MB/TLSv13-12         26.1ms ± 3%    25.0ms ± 1%   -4.20%  (p=0.000 n=14+14)
Throughput/MaxPacket/16MB/TLSv12-12        51.3ms ± 5%    47.5ms ± 1%   -7.52%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-12        53.0ms ± 7%    48.7ms ± 1%   -8.10%  (p=0.000 n=14+14)
Throughput/MaxPacket/32MB/TLSv12-12        99.0ms ± 3%    94.7ms ± 0%   -4.40%  (p=0.000 n=14+13)
Throughput/MaxPacket/32MB/TLSv13-12         100ms ± 3%      96ms ± 1%   -4.09%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12         194ms ± 4%     187ms ± 1%   -3.76%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv13-12         200ms ± 3%     191ms ± 1%   -4.33%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12     4.07ms ± 7%    3.93ms ± 3%   -3.59%  (p=0.000 n=14+15)
Throughput/DynamicPacket/1MB/TLSv13-12     4.37ms ± 5%    4.23ms ± 4%   -3.21%  (p=0.008 n=15+15)
Throughput/DynamicPacket/2MB/TLSv12-12     8.86ms ±56%    7.26ms ± 3%  -18.02%  (p=0.000 n=15+15)
Throughput/DynamicPacket/2MB/TLSv13-12     7.45ms ± 4%    7.21ms ± 1%   -3.23%  (p=0.000 n=12+15)
Throughput/DynamicPacket/4MB/TLSv12-12     13.5ms ± 2%    13.0ms ± 1%   -3.65%  (p=0.000 n=14+15)
Throughput/DynamicPacket/4MB/TLSv13-12     14.0ms ±13%    13.2ms ± 1%   -5.76%  (p=0.000 n=13+15)
Throughput/DynamicPacket/8MB/TLSv12-12     25.0ms ± 1%    24.6ms ± 1%   -1.57%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv13-12     25.9ms ± 3%    25.0ms ± 1%   -3.23%  (p=0.000 n=13+15)
Throughput/DynamicPacket/16MB/TLSv12-12    49.8ms ± 3%    48.1ms ± 1%   -3.43%  (p=0.000 n=14+15)
Throughput/DynamicPacket/16MB/TLSv13-12    49.5ms ± 1%    48.8ms ± 0%   -1.31%  (p=0.000 n=14+15)
Throughput/DynamicPacket/32MB/TLSv12-12     101ms ±11%      95ms ± 1%   -6.15%  (p=0.000 n=15+14)
Throughput/DynamicPacket/32MB/TLSv13-12     112ms ±23%      96ms ± 1%  -13.70%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12     196ms ± 3%     189ms ± 1%   -3.66%  (p=0.000 n=12+15)
Throughput/DynamicPacket/64MB/TLSv13-12     194ms ± 1%     192ms ± 1%   -1.28%  (p=0.000 n=15+15)
name                                     old speed      new speed      delta
Throughput/MaxPacket/1MB/TLSv12-12        267MB/s ± 3%   266MB/s ± 3%     ~     (p=0.305 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12        251MB/s ± 2%   250MB/s ± 2%     ~     (p=0.375 n=13+14)
Throughput/MaxPacket/2MB/TLSv12-12        290MB/s ± 3%   294MB/s ± 3%   +1.20%  (p=0.037 n=13+15)
Throughput/MaxPacket/2MB/TLSv13-12        283MB/s ± 6%   293MB/s ± 2%   +3.60%  (p=0.000 n=14+15)
Throughput/MaxPacket/4MB/TLSv12-12        307MB/s ± 7%   325MB/s ± 1%   +6.10%  (p=0.000 n=15+12)
Throughput/MaxPacket/4MB/TLSv13-12        294MB/s ± 8%   321MB/s ± 1%   +9.14%  (p=0.000 n=15+14)
Throughput/MaxPacket/8MB/TLSv12-12        333MB/s ± 2%   341MB/s ± 1%   +2.69%  (p=0.000 n=14+14)
Throughput/MaxPacket/8MB/TLSv13-12        320MB/s ± 5%   335MB/s ± 1%   +4.75%  (p=0.000 n=15+14)
Throughput/MaxPacket/16MB/TLSv12-12       327MB/s ± 5%   353MB/s ± 1%   +8.07%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-12       317MB/s ± 7%   345MB/s ± 1%   +8.72%  (p=0.000 n=14+14)
Throughput/MaxPacket/32MB/TLSv12-12       339MB/s ± 3%   354MB/s ± 0%   +4.59%  (p=0.000 n=14+13)
Throughput/MaxPacket/32MB/TLSv13-12       335MB/s ± 3%   349MB/s ± 1%   +4.26%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12       346MB/s ± 4%   359MB/s ± 1%   +3.87%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv13-12       336MB/s ± 3%   351MB/s ± 1%   +4.49%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12    258MB/s ± 6%   267MB/s ± 3%   +3.68%  (p=0.000 n=14+15)
Throughput/DynamicPacket/1MB/TLSv13-12    240MB/s ± 6%   248MB/s ± 4%   +3.30%  (p=0.008 n=15+15)
Throughput/DynamicPacket/2MB/TLSv12-12    248MB/s ±39%   289MB/s ± 3%  +16.31%  (p=0.000 n=15+15)
Throughput/DynamicPacket/2MB/TLSv13-12    282MB/s ± 4%   291MB/s ± 1%   +3.28%  (p=0.000 n=12+15)
Throughput/DynamicPacket/4MB/TLSv12-12    311MB/s ± 2%   322MB/s ± 1%   +3.77%  (p=0.000 n=14+15)
Throughput/DynamicPacket/4MB/TLSv13-12    301MB/s ±11%   319MB/s ± 1%   +5.89%  (p=0.000 n=13+15)
Throughput/DynamicPacket/8MB/TLSv12-12    335MB/s ± 1%   340MB/s ± 1%   +1.60%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv13-12    324MB/s ± 3%   335MB/s ± 1%   +3.32%  (p=0.000 n=13+15)
Throughput/DynamicPacket/16MB/TLSv12-12   337MB/s ± 3%   349MB/s ± 1%   +3.54%  (p=0.000 n=14+15)
Throughput/DynamicPacket/16MB/TLSv13-12   339MB/s ± 1%   344MB/s ± 0%   +1.32%  (p=0.000 n=14+15)
Throughput/DynamicPacket/32MB/TLSv12-12   332MB/s ±10%   353MB/s ± 1%   +6.31%  (p=0.000 n=15+14)
Throughput/DynamicPacket/32MB/TLSv13-12   304MB/s ±20%   348MB/s ± 1%  +14.58%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12   343MB/s ± 3%   356MB/s ± 1%   +3.78%  (p=0.000 n=12+15)
Throughput/DynamicPacket/64MB/TLSv13-12   345MB/s ± 1%   350MB/s ± 1%   +1.29%  (p=0.000 n=15+15)
name                                     old alloc/op   new alloc/op   delta
Throughput/MaxPacket/1MB/TLSv12-12          213kB ± 1%     210kB ± 1%   -1.38%  (p=0.000 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12          251kB ± 0%     248kB ± 0%   -1.16%  (p=0.000 n=14+15)
Throughput/MaxPacket/2MB/TLSv12-12          216kB ± 1%     211kB ± 1%   -2.28%  (p=0.000 n=15+15)
Throughput/MaxPacket/2MB/TLSv13-12          254kB ± 1%     249kB ± 1%   -2.17%  (p=0.000 n=15+14)
Throughput/MaxPacket/4MB/TLSv12-12          220kB ± 1%     211kB ± 0%   -4.18%  (p=0.000 n=15+14)
Throughput/MaxPacket/4MB/TLSv13-12          259kB ± 1%     249kB ± 1%   -3.86%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12          228kB ± 1%     213kB ± 1%   -6.62%  (p=0.000 n=12+14)
Throughput/MaxPacket/8MB/TLSv13-12          267kB ± 1%     251kB ± 1%   -5.66%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv12-12         244kB ± 2%     215kB ± 3%  -11.78%  (p=0.000 n=14+15)
Throughput/MaxPacket/16MB/TLSv13-12         282kB ± 2%     252kB ± 2%  -10.45%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv12-12         274kB ± 3%     216kB ± 1%  -21.26%  (p=0.000 n=15+14)
Throughput/MaxPacket/32MB/TLSv13-12         313kB ± 3%     255kB ± 3%  -18.57%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12         338kB ± 6%     218kB ± 1%  -35.62%  (p=0.000 n=15+13)
Throughput/MaxPacket/64MB/TLSv13-12         377kB ± 5%     261kB ± 6%  -30.68%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12      261kB ± 1%     255kB ± 2%   -2.23%  (p=0.000 n=13+15)
Throughput/DynamicPacket/1MB/TLSv13-12      294kB ± 1%     289kB ± 1%   -1.48%  (p=0.000 n=15+15)
Throughput/DynamicPacket/2MB/TLSv12-12      262kB ± 4%     255kB ± 2%   -2.70%  (p=0.000 n=14+14)
Throughput/DynamicPacket/2MB/TLSv13-12      296kB ± 1%     289kB ± 2%   -2.44%  (p=0.000 n=15+15)
Throughput/DynamicPacket/4MB/TLSv12-12      266kB ± 4%     257kB ± 4%   -3.38%  (p=0.000 n=15+14)
Throughput/DynamicPacket/4MB/TLSv13-12      300kB ± 1%     290kB ± 3%   -3.36%  (p=0.000 n=14+15)
Throughput/DynamicPacket/8MB/TLSv12-12      276kB ± 5%     256kB ± 3%   -7.34%  (p=0.000 n=14+15)
Throughput/DynamicPacket/8MB/TLSv13-12      303kB ± 2%     290kB ± 3%   -4.53%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv12-12     289kB ± 5%     255kB ± 4%  -11.68%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv13-12     320kB ± 5%     288kB ± 3%   -9.87%  (p=0.000 n=14+15)
Throughput/DynamicPacket/32MB/TLSv12-12     318kB ± 4%     257kB ±12%  -19.09%  (p=0.000 n=15+15)
Throughput/DynamicPacket/32MB/TLSv13-12     350kB ± 4%     290kB ± 4%  -17.22%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12     378kB ± 6%     265kB ±14%  -29.83%  (p=0.000 n=14+15)
Throughput/DynamicPacket/64MB/TLSv13-12     414kB ± 2%     305kB ± 9%  -26.26%  (p=0.000 n=13+15)
name                                     old allocs/op  new allocs/op  delta
Throughput/MaxPacket/1MB/TLSv12-12            586 ± 0%       507 ± 0%  -13.50%  (p=0.000 n=15+12)
Throughput/MaxPacket/1MB/TLSv13-12          1.22k ± 0%     1.14k ± 0%   -6.29%  (p=0.000 n=13+14)
Throughput/MaxPacket/2MB/TLSv12-12            657 ± 0%       507 ± 0%  -22.88%  (p=0.000 n=13+15)
Throughput/MaxPacket/2MB/TLSv13-12          1.29k ± 0%     1.14k ± 0%  -11.35%  (p=0.000 n=14+13)
Throughput/MaxPacket/4MB/TLSv12-12            803 ± 1%       507 ± 0%  -36.84%  (p=0.000 n=15+14)
Throughput/MaxPacket/4MB/TLSv13-12          1.43k ± 1%     1.14k ± 0%  -20.21%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12          1.08k ± 1%     0.51k ± 0%  -53.14%  (p=0.000 n=13+15)
Throughput/MaxPacket/8MB/TLSv13-12          1.71k ± 1%     1.14k ± 0%  -33.17%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv12-12         1.67k ± 1%     0.51k ± 0%  -69.56%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-12         2.29k ± 1%     1.14k ± 0%  -50.00%  (p=0.000 n=14+15)
Throughput/MaxPacket/32MB/TLSv12-12         2.80k ± 2%     0.51k ± 0%  -81.86%  (p=0.000 n=14+15)
Throughput/MaxPacket/32MB/TLSv13-12         3.37k ± 1%     1.14k ± 0%  -66.07%  (p=0.000 n=14+15)
Throughput/MaxPacket/64MB/TLSv12-12         5.04k ± 3%     0.51k ± 0%  -89.89%  (p=0.000 n=15+14)
Throughput/MaxPacket/64MB/TLSv13-12         5.59k ± 1%     1.15k ± 0%  -79.48%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12        601 ± 0%       514 ± 0%  -14.57%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv13-12      1.24k ± 0%     1.15k ± 0%   -6.94%  (p=0.000 n=14+15)
Throughput/DynamicPacket/2MB/TLSv12-12        678 ± 3%       514 ± 0%  -24.18%  (p=0.000 n=14+14)
Throughput/DynamicPacket/2MB/TLSv13-12      1.30k ± 0%     1.15k ± 0%  -11.86%  (p=0.000 n=13+15)
Throughput/DynamicPacket/4MB/TLSv12-12        813 ± 1%       514 ± 0%  -36.76%  (p=0.000 n=13+15)
Throughput/DynamicPacket/4MB/TLSv13-12      1.45k ± 1%     1.15k ± 0%  -20.44%  (p=0.000 n=13+15)
Throughput/DynamicPacket/8MB/TLSv12-12      1.10k ± 1%     0.51k ± 0%  -53.16%  (p=0.000 n=14+15)
Throughput/DynamicPacket/8MB/TLSv13-12      1.72k ± 1%     1.15k ± 0%  -33.33%  (p=0.000 n=14+14)
Throughput/DynamicPacket/16MB/TLSv12-12     1.67k ± 2%     0.51k ± 0%  -69.27%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv13-12     2.26k ± 1%     1.15k ± 0%  -49.20%  (p=0.000 n=15+14)
Throughput/DynamicPacket/32MB/TLSv12-12     2.83k ± 3%     0.51k ± 0%  -81.85%  (p=0.000 n=15+13)
Throughput/DynamicPacket/32MB/TLSv13-12     3.49k ± 6%     1.15k ± 0%  -67.05%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12     5.12k ± 3%     0.52k ± 1%  -89.90%  (p=0.000 n=14+15)
Throughput/DynamicPacket/64MB/TLSv13-12     5.58k ± 1%     1.15k ± 1%  -79.30%  (p=0.000 n=14+15)

Benchmarking against release-branch.go1.18 shows less but consistent improvement:

1.18 bench

name                                     old time/op    new time/op    delta
Throughput/MaxPacket/1MB/TLSv12-12         3.90ms ± 4%    3.92ms ±12%     ~     (p=0.595 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12         4.14ms ± 5%    4.09ms ± 3%     ~     (p=0.118 n=15+13)
Throughput/MaxPacket/2MB/TLSv12-12         7.00ms ± 3%    6.92ms ± 2%   -1.25%  (p=0.008 n=15+14)
Throughput/MaxPacket/2MB/TLSv13-12         7.05ms ± 3%    6.99ms ± 2%   -0.76%  (p=0.041 n=15+14)
Throughput/MaxPacket/4MB/TLSv12-12         12.7ms ± 1%    12.6ms ± 1%     ~     (p=0.274 n=13+15)
Throughput/MaxPacket/4MB/TLSv13-12         12.9ms ± 1%    12.9ms ± 1%     ~     (p=0.744 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12         24.2ms ± 1%    24.0ms ± 1%   -0.49%  (p=0.033 n=15+15)
Throughput/MaxPacket/8MB/TLSv13-12         24.7ms ± 1%    24.5ms ± 1%   -0.79%  (p=0.000 n=15+14)
Throughput/MaxPacket/16MB/TLSv12-12        47.3ms ± 1%    47.2ms ± 3%     ~     (p=0.201 n=14+15)
Throughput/MaxPacket/16MB/TLSv13-12        48.2ms ± 1%    47.9ms ± 1%     ~     (p=0.063 n=15+14)
Throughput/MaxPacket/32MB/TLSv12-12        93.9ms ± 1%    92.3ms ± 0%   -1.74%  (p=0.000 n=14+15)
Throughput/MaxPacket/32MB/TLSv13-12        95.0ms ± 1%    94.3ms ± 1%   -0.80%  (p=0.001 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12         185ms ± 1%     183ms ± 1%   -1.06%  (p=0.000 n=14+13)
Throughput/MaxPacket/64MB/TLSv13-12         189ms ± 1%     188ms ± 3%     ~     (p=0.201 n=14+15)
Throughput/DynamicPacket/1MB/TLSv12-12     3.81ms ± 2%    3.79ms ± 2%   -0.62%  (p=0.046 n=14+15)
Throughput/DynamicPacket/1MB/TLSv13-12     4.13ms ± 4%    4.08ms ± 5%     ~     (p=0.112 n=15+14)
Throughput/DynamicPacket/2MB/TLSv12-12     7.10ms ± 3%    6.98ms ± 4%   -1.73%  (p=0.006 n=15+14)
Throughput/DynamicPacket/2MB/TLSv13-12     7.04ms ± 2%    7.03ms ± 1%     ~     (p=0.847 n=14+15)
Throughput/DynamicPacket/4MB/TLSv12-12     12.8ms ± 2%    12.6ms ± 1%   -1.16%  (p=0.000 n=15+14)
Throughput/DynamicPacket/4MB/TLSv13-12     12.9ms ± 1%    12.8ms ± 1%   -0.89%  (p=0.000 n=14+15)
Throughput/DynamicPacket/8MB/TLSv12-12     24.2ms ± 1%    24.1ms ± 1%   -0.67%  (p=0.005 n=14+14)
Throughput/DynamicPacket/8MB/TLSv13-12     24.6ms ± 1%    24.4ms ± 1%   -0.84%  (p=0.000 n=14+14)
Throughput/DynamicPacket/16MB/TLSv12-12    47.3ms ± 1%    46.9ms ± 1%   -0.78%  (p=0.000 n=13+15)
Throughput/DynamicPacket/16MB/TLSv13-12    48.2ms ± 1%    47.9ms ± 2%   -0.65%  (p=0.023 n=15+14)
Throughput/DynamicPacket/32MB/TLSv12-12    93.5ms ± 1%    92.6ms ± 1%   -0.90%  (p=0.000 n=15+13)
Throughput/DynamicPacket/32MB/TLSv13-12    94.7ms ± 1%    94.7ms ± 1%     ~     (p=0.769 n=14+14)
Throughput/DynamicPacket/64MB/TLSv12-12     186ms ± 2%     185ms ± 1%   -0.75%  (p=0.008 n=15+14)
Throughput/DynamicPacket/64MB/TLSv13-12     189ms ± 1%     188ms ± 1%   -0.72%  (p=0.000 n=13+15)
name                                     old speed      new speed      delta
Throughput/MaxPacket/1MB/TLSv12-12        269MB/s ± 4%   268MB/s ±11%     ~     (p=0.595 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12        253MB/s ± 4%   256MB/s ± 3%     ~     (p=0.118 n=15+13)
Throughput/MaxPacket/2MB/TLSv12-12        300MB/s ± 3%   303MB/s ± 2%   +1.26%  (p=0.008 n=15+14)
Throughput/MaxPacket/2MB/TLSv13-12        298MB/s ± 3%   300MB/s ± 2%   +0.76%  (p=0.041 n=15+14)
Throughput/MaxPacket/4MB/TLSv12-12        331MB/s ± 1%   332MB/s ± 1%     ~     (p=0.279 n=13+15)
Throughput/MaxPacket/4MB/TLSv13-12        325MB/s ± 1%   325MB/s ± 1%     ~     (p=0.736 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12        347MB/s ± 1%   349MB/s ± 1%   +0.49%  (p=0.034 n=15+15)
Throughput/MaxPacket/8MB/TLSv13-12        340MB/s ± 1%   343MB/s ± 1%   +0.79%  (p=0.000 n=15+14)
Throughput/MaxPacket/16MB/TLSv12-12       354MB/s ± 1%   356MB/s ± 2%     ~     (p=0.197 n=14+15)
Throughput/MaxPacket/16MB/TLSv13-12       348MB/s ± 1%   350MB/s ± 1%     ~     (p=0.063 n=15+14)
Throughput/MaxPacket/32MB/TLSv12-12       357MB/s ± 1%   364MB/s ± 0%   +1.77%  (p=0.000 n=14+15)
Throughput/MaxPacket/32MB/TLSv13-12       353MB/s ± 1%   356MB/s ± 1%   +0.81%  (p=0.001 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12       363MB/s ± 1%   367MB/s ± 1%   +1.07%  (p=0.000 n=14+13)
Throughput/MaxPacket/64MB/TLSv13-12       355MB/s ± 1%   356MB/s ± 3%     ~     (p=0.201 n=14+15)
Throughput/DynamicPacket/1MB/TLSv12-12    275MB/s ± 2%   277MB/s ± 2%   +0.63%  (p=0.045 n=14+15)
Throughput/DynamicPacket/1MB/TLSv13-12    254MB/s ± 4%   257MB/s ± 4%     ~     (p=0.109 n=15+14)
Throughput/DynamicPacket/2MB/TLSv12-12    295MB/s ± 3%   300MB/s ± 4%   +1.75%  (p=0.006 n=15+14)
Throughput/DynamicPacket/2MB/TLSv13-12    298MB/s ± 2%   298MB/s ± 1%     ~     (p=0.821 n=14+15)
Throughput/DynamicPacket/4MB/TLSv12-12    328MB/s ± 2%   332MB/s ± 1%   +1.17%  (p=0.000 n=15+14)
Throughput/DynamicPacket/4MB/TLSv13-12    324MB/s ± 1%   327MB/s ± 1%   +0.90%  (p=0.000 n=14+15)
Throughput/DynamicPacket/8MB/TLSv12-12    346MB/s ± 1%   348MB/s ± 1%   +0.68%  (p=0.005 n=14+14)
Throughput/DynamicPacket/8MB/TLSv13-12    341MB/s ± 1%   344MB/s ± 1%   +0.85%  (p=0.000 n=14+14)
Throughput/DynamicPacket/16MB/TLSv12-12   355MB/s ± 1%   357MB/s ± 1%   +0.78%  (p=0.000 n=13+15)
Throughput/DynamicPacket/16MB/TLSv13-12   348MB/s ± 1%   350MB/s ± 2%   +0.67%  (p=0.023 n=15+14)
Throughput/DynamicPacket/32MB/TLSv12-12   359MB/s ± 1%   362MB/s ± 1%   +0.91%  (p=0.000 n=15+13)
Throughput/DynamicPacket/32MB/TLSv13-12   354MB/s ± 1%   354MB/s ± 1%     ~     (p=0.778 n=14+14)
Throughput/DynamicPacket/64MB/TLSv12-12   361MB/s ± 2%   364MB/s ± 1%   +0.75%  (p=0.008 n=15+14)
Throughput/DynamicPacket/64MB/TLSv13-12   354MB/s ± 1%   357MB/s ± 1%   +0.73%  (p=0.000 n=13+15)
name                                     old alloc/op   new alloc/op   delta
Throughput/MaxPacket/1MB/TLSv12-12          208kB ± 0%     205kB ± 0%   -1.09%  (p=0.000 n=15+15)
Throughput/MaxPacket/1MB/TLSv13-12          245kB ± 0%     243kB ± 0%   -0.85%  (p=0.000 n=15+15)
Throughput/MaxPacket/2MB/TLSv12-12          210kB ± 0%     206kB ± 0%   -2.03%  (p=0.000 n=15+15)
Throughput/MaxPacket/2MB/TLSv13-12          247kB ± 0%     243kB ± 0%   -1.68%  (p=0.000 n=15+15)
Throughput/MaxPacket/4MB/TLSv12-12          215kB ± 1%     206kB ± 1%   -4.17%  (p=0.000 n=15+15)
Throughput/MaxPacket/4MB/TLSv13-12          251kB ± 1%     244kB ± 0%   -2.98%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12          223kB ± 1%     207kB ± 1%   -7.14%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv13-12          260kB ± 1%     245kB ± 1%   -5.95%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv12-12         241kB ± 2%     208kB ± 1%  -13.86%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-12         277kB ± 1%     246kB ± 1%  -11.12%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv12-12         276kB ± 2%     213kB ± 3%  -22.86%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv13-12         312kB ± 2%     250kB ± 2%  -20.12%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12         343kB ± 2%     219kB ± 2%  -36.11%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv13-12         377kB ± 2%     256kB ± 2%  -32.15%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12      244kB ± 1%     242kB ± 2%   -0.76%  (p=0.016 n=14+15)
Throughput/DynamicPacket/1MB/TLSv13-12      280kB ± 1%     277kB ± 1%   -1.06%  (p=0.000 n=15+15)
Throughput/DynamicPacket/2MB/TLSv12-12      247kB ± 2%     242kB ± 1%   -1.91%  (p=0.000 n=15+15)
Throughput/DynamicPacket/2MB/TLSv13-12      282kB ± 1%     278kB ± 1%   -1.45%  (p=0.000 n=15+15)
Throughput/DynamicPacket/4MB/TLSv12-12      251kB ± 2%     241kB ± 2%   -3.98%  (p=0.000 n=15+15)
Throughput/DynamicPacket/4MB/TLSv13-12      287kB ± 1%     278kB ± 1%   -3.17%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv12-12      260kB ± 3%     243kB ± 2%   -6.28%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv13-12      294kB ± 2%     279kB ± 1%   -5.22%  (p=0.000 n=15+14)
Throughput/DynamicPacket/16MB/TLSv12-12     276kB ± 4%     245kB ± 4%  -11.18%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv13-12     310kB ± 3%     280kB ± 1%   -9.94%  (p=0.000 n=15+15)
Throughput/DynamicPacket/32MB/TLSv12-12     309kB ± 4%     250kB ± 5%  -19.06%  (p=0.000 n=15+14)
Throughput/DynamicPacket/32MB/TLSv13-12     345kB ± 3%     283kB ± 3%  -18.10%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12     385kB ± 6%     247kB ± 8%  -35.86%  (p=0.000 n=15+13)
Throughput/DynamicPacket/64MB/TLSv13-12     414kB ± 5%     290kB ± 4%  -30.04%  (p=0.000 n=15+15)
name                                     old allocs/op  new allocs/op  delta
Throughput/MaxPacket/1MB/TLSv12-12            591 ± 1%       505 ± 0%  -14.57%  (p=0.000 n=15+13)
Throughput/MaxPacket/1MB/TLSv13-12          1.22k ± 0%     1.14k ± 0%   -6.59%  (p=0.000 n=15+15)
Throughput/MaxPacket/2MB/TLSv12-12            670 ± 0%       505 ± 0%  -24.66%  (p=0.000 n=15+13)
Throughput/MaxPacket/2MB/TLSv13-12          1.30k ± 0%     1.14k ± 0%  -11.97%  (p=0.000 n=15+13)
Throughput/MaxPacket/4MB/TLSv12-12            829 ± 1%       505 ± 0%  -39.06%  (p=0.000 n=15+15)
Throughput/MaxPacket/4MB/TLSv13-12          1.45k ± 0%     1.14k ± 0%  -21.27%  (p=0.000 n=15+15)
Throughput/MaxPacket/8MB/TLSv12-12          1.15k ± 1%     0.51k ± 0%  -56.01%  (p=0.000 n=15+13)
Throughput/MaxPacket/8MB/TLSv13-12          1.77k ± 1%     1.14k ± 0%  -35.44%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv12-12         1.80k ± 2%     0.51k ± 0%  -71.88%  (p=0.000 n=15+15)
Throughput/MaxPacket/16MB/TLSv13-12         2.39k ± 1%     1.14k ± 0%  -52.32%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv12-12         3.10k ± 1%     0.51k ± 0%  -83.65%  (p=0.000 n=15+15)
Throughput/MaxPacket/32MB/TLSv13-12         3.67k ± 2%     1.14k ± 0%  -68.84%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv12-12         5.64k ± 3%     0.51k ± 0%  -90.98%  (p=0.000 n=15+15)
Throughput/MaxPacket/64MB/TLSv13-12         6.12k ± 3%     1.14k ± 0%  -81.29%  (p=0.000 n=15+15)
Throughput/DynamicPacket/1MB/TLSv12-12        602 ± 0%       510 ± 0%  -15.23%  (p=0.000 n=15+13)
Throughput/DynamicPacket/1MB/TLSv13-12      1.23k ± 0%     1.15k ± 0%   -7.13%  (p=0.000 n=12+15)
Throughput/DynamicPacket/2MB/TLSv12-12        680 ± 0%       510 ± 0%  -24.96%  (p=0.000 n=15+14)
Throughput/DynamicPacket/2MB/TLSv13-12      1.31k ± 0%     1.15k ± 0%  -12.56%  (p=0.000 n=13+12)
Throughput/DynamicPacket/4MB/TLSv12-12        835 ± 1%       510 ± 0%  -38.95%  (p=0.000 n=15+11)
Throughput/DynamicPacket/4MB/TLSv13-12      1.46k ± 0%     1.15k ± 0%  -21.73%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv12-12      1.16k ± 1%     0.51k ± 0%  -56.00%  (p=0.000 n=15+15)
Throughput/DynamicPacket/8MB/TLSv13-12      1.78k ± 1%     1.15k ± 0%  -35.63%  (p=0.000 n=14+15)
Throughput/DynamicPacket/16MB/TLSv12-12     1.81k ± 2%     0.51k ± 0%  -71.72%  (p=0.000 n=15+15)
Throughput/DynamicPacket/16MB/TLSv13-12     2.40k ± 1%     1.15k ± 0%  -52.18%  (p=0.000 n=14+11)
Throughput/DynamicPacket/32MB/TLSv12-12     3.07k ± 2%     0.51k ± 1%  -83.30%  (p=0.000 n=15+14)
Throughput/DynamicPacket/32MB/TLSv13-12     3.67k ± 2%     1.15k ± 0%  -68.70%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv12-12     5.68k ± 3%     0.51k ± 1%  -90.96%  (p=0.000 n=15+15)
Throughput/DynamicPacket/64MB/TLSv13-12     6.17k ± 3%     1.15k ± 0%  -81.38%  (p=0.000 n=15+15)

Note that allocs per operation became constant for each kind of a test.

[gopherbot]

Change https://go.dev/cl/409334 mentions this issue: crypto/tls: reduce the number of allocations made for Conn.Read calls

[dmitshur]

CC @golang/security.

[gopherbot]

Change https://go.dev/cl/464835 mentions this issue: crypto/tls: store value atLeastReader in tls.Conn