55310403dd
During benchmark of an internal tool we found out that (*Buffer).Reset() was
surprisingly showing up in CPU profiles.
This CL contains two related changes aimed at speeding up Reset():
1. Create a fast path for Truncate(0) by moving the logic to Reset()
(this makes Reset() a simple leaf func that gets inlined since it
gets compiled to 3 MOVx instructions). Accordingly change calls in
the rest of the Buffer methods to call Reset() instead of Truncate(0).
2. Reorder the fields in the Buffer struct so that frequently accessed
fields are packed together (buf, off, lastRead). This also make them
likely to be in the same cacheline.
Ideally it would be advisable to have Buffer{} cacheline-aligned, but I
couldn't find a way to do this without changing the size of the bootstrap
array (but this will cause some regressions, because it will make duffcopy
show up in CPU profiles where it wasn't showing up before).
go1 benchmarks are not really affected, but some other benchmarks that
exercise Buffer more show improvements:
name old time/op new time/op delta
BinaryTree17-4 2.46s ± 9% 2.43s ± 3% ~ (p=0.982 n=14+14)
Fannkuch11-4 2.98s ± 1% 2.90s ± 1% -2.58% (p=0.000 n=15+14)
FmtFprintfEmpty-4 45.2ns ± 1% 45.2ns ± 1% ~ (p=0.494 n=14+15)
FmtFprintfString-4 76.8ns ± 1% 83.1ns ± 2% +8.23% (p=0.000 n=10+15)
FmtFprintfInt-4 78.0ns ± 2% 74.6ns ± 1% -4.46% (p=0.000 n=15+15)
FmtFprintfIntInt-4 113ns ± 1% 109ns ± 2% -2.91% (p=0.000 n=13+15)
FmtFprintfPrefixedInt-4 152ns ± 2% 143ns ± 2% -6.04% (p=0.000 n=15+14)
FmtFprintfFloat-4 224ns ± 1% 222ns ± 2% -1.08% (p=0.001 n=15+14)
FmtManyArgs-4 464ns ± 2% 463ns ± 2% ~ (p=0.303 n=14+15)
GobDecode-4 6.25ms ± 2% 6.32ms ± 3% +1.20% (p=0.002 n=14+14)
GobEncode-4 5.41ms ± 2% 5.41ms ± 2% ~ (p=0.967 n=15+15)
Gzip-4 215ms ± 2% 218ms ± 2% +1.35% (p=0.002 n=15+15)
Gunzip-4 34.3ms ± 2% 34.2ms ± 2% ~ (p=0.539 n=15+15)
HTTPClientServer-4 76.4µs ± 2% 75.4µs ± 1% -1.31% (p=0.000 n=15+15)
JSONEncode-4 14.7ms ± 2% 14.6ms ± 3% ~ (p=0.094 n=14+14)
JSONDecode-4 48.0ms ± 1% 48.5ms ± 1% +0.92% (p=0.001 n=14+12)
Mandelbrot200-4 4.04ms ± 2% 4.06ms ± 1% ~ (p=0.108 n=15+13)
GoParse-4 2.99ms ± 2% 3.00ms ± 1% ~ (p=0.130 n=15+13)
RegexpMatchEasy0_32-4 78.3ns ± 1% 79.5ns ± 1% +1.51% (p=0.000 n=15+14)
RegexpMatchEasy0_1K-4 185ns ± 1% 186ns ± 1% +0.76% (p=0.005 n=15+15)
RegexpMatchEasy1_32-4 79.0ns ± 2% 76.7ns ± 1% -2.87% (p=0.000 n=14+15)
name old speed new speed delta
GobDecode-4 123MB/s ± 2% 121MB/s ± 3% -1.18% (p=0.002 n=14+14)
GobEncode-4 142MB/s ± 2% 142MB/s ± 1% ~ (p=0.959 n=15+15)
Gzip-4 90.3MB/s ± 2% 89.1MB/s ± 2% -1.34% (p=0.002 n=15+15)
Gunzip-4 565MB/s ± 2% 567MB/s ± 2% ~ (p=0.539 n=15+15)
JSONEncode-4 132MB/s ± 2% 133MB/s ± 3% ~ (p=0.091 n=14+14)
JSONDecode-4 40.4MB/s ± 1% 40.0MB/s ± 1% -0.92% (p=0.001 n=14+12)
GoParse-4 19.4MB/s ± 2% 19.3MB/s ± 1% ~ (p=0.121 n=15+13)
RegexpMatchEasy0_32-4 409MB/s ± 1% 403MB/s ± 1% -1.47% (p=0.000 n=15+14)
RegexpMatchEasy0_1K-4 5.53GB/s ± 1% 5.49GB/s ± 1% -0.86% (p=0.002 n=15+15)
RegexpMatchEasy1_32-4 405MB/s ± 2% 417MB/s ± 1% +2.94% (p=0.000 n=14+15)
name old time/op new time/op delta
PoolsSingle1K-4 34.9ns ± 2% 30.4ns ± 4% -12.80% (p=0.000 n=15+15)
PoolsSingle64K-4 36.9ns ± 1% 34.4ns ± 4% -6.72% (p=0.000 n=14+15)
PoolsRandomSmall-4 34.8ns ± 3% 29.5ns ± 1% -15.19% (p=0.000 n=15+14)
PoolsRandomLarge-4 38.6ns ± 1% 34.3ns ± 3% -11.17% (p=0.000 n=14+15)
PoolSingle1K-4 26.1ns ± 1% 21.2ns ± 2% -18.59% (p=0.000 n=15+14)
PoolSingle64K-4 26.7ns ± 2% 21.5ns ± 2% -19.72% (p=0.000 n=15+15)
MakeSingle1K-4 24.2ns ± 2% 24.3ns ± 3% ~ (p=0.132 n=13+15)
MakeSingle64K-4 6.76µs ± 1% 6.96µs ± 5% +2.94% (p=0.002 n=13+13)
MakeRandomSmall-4 531ns ± 4% 538ns ± 5% ~ (p=0.066 n=14+15)
MakeRandomLarge-4 152µs ± 0% 152µs ± 1% -0.31% (p=0.001 n=14+13)
Change-Id: I86d7d9d2cac65335baf62214fbb35ba0fd8f9528
Reviewed-on: https://go-review.googlesource.com/37416
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
|
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| AUTHORS | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| favicon.ico | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| robots.txt | ||
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 3.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Download and Install
Binary Distributions
Official binary distributions are available at https://golang.org/dl/.
After downloading a binary release, visit https://golang.org/doc/install or load doc/install.html in your web browser for installation instructions.
Install From Source
If a binary distribution is not available for your combination of operating system and architecture, visit https://golang.org/doc/install/source or load doc/install-source.html in your web browser for source installation instructions.
Contributing
Go is the work of hundreds of contributors. We appreciate your help!
To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html
Note that the Go project does not use GitHub pull requests, and that we use the issue tracker for bug reports and proposals only. See https://golang.org/wiki/Questions for a list of places to ask questions about the Go language.