1
0
mirror of https://github.com/golang/go synced 2024-09-24 07:20:14 -06:00
The Go programming language
Go to file
Josh Bleecher Snyder f77e7ed7e3 cmd/compile: use a sync.Pool and string interning when printing types
CL 214239 improved type printing, but introduced performance regressions:
3-5% memory increase, 1-2% CPU time increase.

There were two primary sources of the memory regression:

* allocating a bytes.Buffer for every type to print
* always printing to that buffer, even when we could return a constant string

This change addresses both of those regressions.
The sync.Pool allows buffer re-use.
String interning prevents allocation for re-used strings.

It addresses some, but not all, of the CPU time regression.


Memory performance impact vs master:

name        old alloc/op      new alloc/op      delta
Template         37.6MB ± 0%       36.3MB ± 0%  -3.30%  (p=0.008 n=5+5)
Unicode          28.7MB ± 0%       28.3MB ± 0%  -1.55%  (p=0.008 n=5+5)
GoTypes           127MB ± 0%        122MB ± 0%  -4.38%  (p=0.008 n=5+5)
Compiler          584MB ± 0%        568MB ± 0%  -2.72%  (p=0.008 n=5+5)
SSA              1.99GB ± 0%       1.95GB ± 0%  -1.97%  (p=0.008 n=5+5)
Flate            23.5MB ± 0%       22.8MB ± 0%  -2.84%  (p=0.008 n=5+5)
GoParser         29.2MB ± 0%       28.0MB ± 0%  -4.17%  (p=0.008 n=5+5)
Reflect          81.9MB ± 0%       78.6MB ± 0%  -4.09%  (p=0.008 n=5+5)
Tar              35.3MB ± 0%       34.1MB ± 0%  -3.29%  (p=0.008 n=5+5)
XML              45.5MB ± 0%       44.3MB ± 0%  -2.61%  (p=0.008 n=5+5)
[Geo mean]       82.4MB            79.9MB       -3.09%

name        old allocs/op     new allocs/op     delta
Template           394k ± 0%         363k ± 0%  -7.73%  (p=0.008 n=5+5)
Unicode            340k ± 0%         329k ± 0%  -3.25%  (p=0.008 n=5+5)
GoTypes           1.41M ± 0%        1.28M ± 0%  -9.54%  (p=0.008 n=5+5)
Compiler          5.77M ± 0%        5.39M ± 0%  -6.58%  (p=0.008 n=5+5)
SSA               19.1M ± 0%        18.1M ± 0%  -5.13%  (p=0.008 n=5+5)
Flate              247k ± 0%         228k ± 0%  -7.50%  (p=0.008 n=5+5)
GoParser           325k ± 0%         295k ± 0%  -9.24%  (p=0.008 n=5+5)
Reflect           1.04M ± 0%        0.95M ± 0%  -8.48%  (p=0.008 n=5+5)
Tar                365k ± 0%         336k ± 0%  -7.93%  (p=0.008 n=5+5)
XML                449k ± 0%         417k ± 0%  -7.10%  (p=0.008 n=5+5)
[Geo mean]         882k              818k       -7.26%


Memory performance going from 52c4488471,
which is the commit preceding CL 214239, to this change:

name        old alloc/op      new alloc/op      delta
Template         36.5MB ± 0%       36.3MB ± 0%  -0.37%  (p=0.008 n=5+5)
Unicode          28.3MB ± 0%       28.3MB ± 0%  -0.06%  (p=0.008 n=5+5)
GoTypes           123MB ± 0%        122MB ± 0%  -0.64%  (p=0.008 n=5+5)
Compiler          571MB ± 0%        568MB ± 0%  -0.51%  (p=0.008 n=5+5)
SSA              1.96GB ± 0%       1.95GB ± 0%  -0.13%  (p=0.008 n=5+5)
Flate            22.8MB ± 0%       22.8MB ± 0%    ~     (p=0.421 n=5+5)
GoParser         28.1MB ± 0%       28.0MB ± 0%  -0.37%  (p=0.008 n=5+5)
Reflect          78.8MB ± 0%       78.6MB ± 0%  -0.32%  (p=0.008 n=5+5)
Tar              34.3MB ± 0%       34.1MB ± 0%  -0.35%  (p=0.008 n=5+5)
XML              44.3MB ± 0%       44.3MB ± 0%  +0.05%  (p=0.032 n=5+5)
[Geo mean]       80.1MB            79.9MB       -0.27%

name        old allocs/op     new allocs/op     delta
Template           372k ± 0%         363k ± 0%  -2.46%  (p=0.008 n=5+5)
Unicode            333k ± 0%         329k ± 0%  -0.97%  (p=0.008 n=5+5)
GoTypes           1.33M ± 0%        1.28M ± 0%  -3.71%  (p=0.008 n=5+5)
Compiler          5.53M ± 0%        5.39M ± 0%  -2.50%  (p=0.008 n=5+5)
SSA               18.3M ± 0%        18.1M ± 0%  -1.22%  (p=0.008 n=5+5)
Flate              234k ± 0%         228k ± 0%  -2.44%  (p=0.008 n=5+5)
GoParser           305k ± 0%         295k ± 0%  -3.23%  (p=0.008 n=5+5)
Reflect            980k ± 0%         949k ± 0%  -3.12%  (p=0.008 n=5+5)
Tar                345k ± 0%         336k ± 0%  -2.69%  (p=0.008 n=5+5)
XML                425k ± 0%         417k ± 0%  -1.72%  (p=0.008 n=5+5)
[Geo mean]         838k              818k       -2.41%


Remaining CPU time regression, that is,
the change from before CL 214239 to this change:

name        old time/op       new time/op       delta
Template          208ms ± 2%        209ms ± 1%    ~     (p=0.181 n=47+46)
Unicode          82.9ms ± 2%       81.9ms ± 2%  -1.25%  (p=0.000 n=50+48)
GoTypes           709ms ± 3%        714ms ± 3%  +0.77%  (p=0.003 n=48+49)
Compiler          3.31s ± 2%        3.32s ± 2%    ~     (p=0.271 n=48+48)
SSA               10.8s ± 1%        10.9s ± 1%  +0.61%  (p=0.000 n=46+47)
Flate             134ms ± 2%        134ms ± 1%  +0.41%  (p=0.002 n=48+46)
GoParser          166ms ± 2%        167ms ± 2%  +0.41%  (p=0.010 n=46+48)
Reflect           440ms ± 4%        444ms ± 4%  +1.05%  (p=0.002 n=50+49)
Tar               183ms ± 2%        184ms ± 2%    ~     (p=0.074 n=45+45)
XML               247ms ± 2%        248ms ± 2%  +0.67%  (p=0.001 n=49+48)
[Geo mean]        425ms             427ms       +0.34%

name        old user-time/op  new user-time/op  delta
Template          271ms ± 2%        271ms ± 2%    ~     (p=0.654 n=48+48)
Unicode           117ms ± 2%        116ms ± 3%    ~     (p=0.458 n=47+45)
GoTypes           952ms ± 3%        963ms ± 2%  +1.11%  (p=0.000 n=48+49)
Compiler          4.50s ± 5%        4.49s ± 7%    ~     (p=0.894 n=50+50)
SSA               15.0s ± 2%        15.1s ± 2%  +0.46%  (p=0.015 n=50+49)
Flate             166ms ± 2%        167ms ± 2%  +0.40%  (p=0.005 n=49+48)
GoParser          202ms ± 2%        203ms ± 2%  +0.60%  (p=0.002 n=49+47)
Reflect           583ms ± 3%        588ms ± 3%  +0.82%  (p=0.001 n=49+46)
Tar               223ms ± 2%        224ms ± 2%  +0.37%  (p=0.046 n=48+46)
XML               310ms ± 2%        311ms ± 2%  +0.46%  (p=0.009 n=50+49)
[Geo mean]        554ms             556ms       +0.36%


Change-Id: I85951a6538373ef4309a2cc366cc1ebaf1f4582d
Reviewed-on: https://go-review.googlesource.com/c/go/+/214818
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
2020-01-15 22:02:44 +00:00
.github .github: add link to questions in ISSUE_TEMPLATE 2020-01-06 17:05:31 +00:00
api go/build: rename WorkingDir to Dir 2019-12-17 14:59:30 +00:00
doc spec: add missing space in EBNF 2020-01-15 05:32:51 +00:00
lib/time lib/time: update tz data to 2019c 2019-11-26 12:03:08 +00:00
misc misc/cgo/test: re-enable darwin cgo tests in race mode 2020-01-10 10:04:49 +00:00
src cmd/compile: use a sync.Pool and string interning when printing types 2020-01-15 22:02:44 +00:00
test cmd/compile: give every really deep type a unique name 2020-01-08 18:43:55 +00:00
.gitattributes
.gitignore .gitignore: ignore src/cmd/dist/dist 2017-10-28 21:55:49 +00:00
AUTHORS A+C: change email address for Akhil Indurti 2019-09-09 15:30:38 +00:00
CONTRIBUTING.md all: restore changes from faulty merge/revert 2018-02-12 20:13:59 +00:00
CONTRIBUTORS C: add missing name 2020-01-14 15:51:35 +00:00
favicon.ico website: recreate 16px and 32px favicon 2016-08-25 15:43:32 +00:00
LICENSE doc: revert copyright date to 2009 2016-06-01 22:40:04 +00:00
PATENTS
README.md README: linkify some paths 2018-06-06 18:07:01 +00:00
robots.txt
SECURITY.md SECURITY.md: update go versions 2019-09-26 15:34:57 +00:00

The Go Programming Language

Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.

Gopher image 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 thousands of contributors. We appreciate your help!

To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html

Note that the Go project uses 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.