The Go programming language
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Andy Pan 970b1c042c os: increase the amount of data transfer for sendfile(2) to reduce syscalls
For the moment, Go calls sendfile(2) to transfer at most 4MB at a time
while sendfile(2) actually allows a larger amount of data on one call.
To reduce system calls of sendfile(2) during data copying, we should
specify the number of bytes to copy as large as possible.

This optimization is especially advantageous for bulky file-to-file copies,
it would lead to a performance boost, the magnitude of this performance
increase may not be very exciting, but it can also cut down the CPU overhead
by decreasing the number of system calls.

This is also how we've done in sendfile_windows.go with TransmitFile.

goos: linux
goarch: amd64
pkg: os
cpu: DO-Premium-AMD
           │    old     │                new                │
           │   sec/op   │   sec/op    vs base               │
SendFile-8   1.135 ± 4%   1.052 ± 3%  -7.24% (p=0.000 n=10)

           │     old      │                 new                 │
           │     B/s      │     B/s       vs base               │
SendFile-8   902.5Mi ± 4%   973.0Mi ± 3%  +7.81% (p=0.000 n=10)

           │    old     │              new               │
           │    B/op    │    B/op     vs base            │
SendFile-8   272.0 ± 0%   272.0 ± 0%  ~ (p=1.000 n=10) ¹
¹ all samples are equal

           │    old     │              new               │
           │ allocs/op  │ allocs/op   vs base            │
SendFile-8   20.00 ± 0%   20.00 ± 0%  ~ (p=1.000 n=10) ¹
¹ all samples are equal

Change-Id: Ib4d4c6bc693e23db24697363b29226f0c9776bb0
Reviewed-on: https://go-review.googlesource.com/c/go/+/605235
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
Run-TryBot: Andy Pan <panjf2000@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
2024-08-15 20:21:47 +00:00
.github .github: update language change proposal template 2024-08-08 19:02:29 +00:00
api bytes, strings: add Lines, SplitSeq, SplitAfterSeq, FieldsSeq, FieldsFuncSeq 2024-08-14 18:23:13 +00:00
doc bytes, strings: add Lines, SplitSeq, SplitAfterSeq, FieldsSeq, FieldsFuncSeq 2024-08-14 18:23:13 +00:00
lib/time lib/time: use consistent directory in mkzip usage message 2024-03-04 17:32:07 +00:00
misc syscall,misc/wasm: fix path expansion on non-unix platforms 2024-08-09 21:22:25 +00:00
src os: increase the amount of data transfer for sendfile(2) to reduce syscalls 2024-08-15 20:21:47 +00:00
test Revert "go/types, types2: only use fileVersion if 1.21 or greater" 2024-08-15 14:43:25 +00:00
.gitattributes
.gitignore runtime,internal: move runtime/internal/sys to internal/runtime/sys 2024-07-23 19:05:35 +00:00
CONTRIBUTING.md doc: normalize proposal-process links 2023-03-29 22:00:27 +00:00
LICENSE LICENSE: update per Google Legal 2024-08-09 14:54:31 +00:00
PATENTS
README.md README: fix CC BY license name 2024-07-22 17:45:27 +00:00
SECURITY.md SECURITY.md: update the Reporting a Vulnerability link 2023-09-22 21:17:24 +00:00
codereview.cfg
go.env cmd/go: additional doc-inspired tests and bug fixes 2023-06-06 19:18:46 +00:00

README.md

The Go Programming Language

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