qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-18 04:14:49 -07:00
Code Releases Activity
The Go programming language
23,358 Commits 58 Branches 402 Tags 522 MiB
Go 89.6%
Assembly 5.2%
HTML 4.8%
C 0.2%
Shell 0.1%
54af9a3ba5
Go to file
Russ Cox 54af9a3ba5 runtime: reintroduce ``dead'' space during GC scan 
Reintroduce an optimization discarded during the initial conversion
from 4-bit heap bitmaps to 2-bit heap bitmaps: when we reach the
place in the bitmap where there are no more pointers, mark that position
for the GC so that it can avoid scanning past that place.

During heapBitsSetType we can also avoid initializing heap bitmap
beyond that location, which gives a bit of a win compared to Go 1.4.
This particular optimization (not initializing the heap bitmap) may not last:
we might change typedmemmove to use the heap bitmap, in which
case it would all need to be initialized. The early stop in the GC scan
will stay no matter what.

Compared to Go 1.4 (github.com/rsc/go, branch go14bench):
name                    old mean              new mean              delta
SetTypeNode64           80.7ns × (1.00,1.01)  57.4ns × (1.00,1.01)  -28.83% (p=0.000)
SetTypeNode64Dead       80.5ns × (1.00,1.01)  13.1ns × (0.99,1.02)  -83.77% (p=0.000)
SetTypeNode64Slice      2.16µs × (1.00,1.01)  1.54µs × (1.00,1.01)  -28.75% (p=0.000)
SetTypeNode64DeadSlice  2.16µs × (1.00,1.01)  1.52µs × (1.00,1.00)  -29.74% (p=0.000)

Compared to previous CL:
name                    old mean              new mean              delta
SetTypeNode64           56.7ns × (1.00,1.00)  57.4ns × (1.00,1.01)   +1.19% (p=0.000)
SetTypeNode64Dead       57.2ns × (1.00,1.00)  13.1ns × (0.99,1.02)  -77.15% (p=0.000)
SetTypeNode64Slice      1.56µs × (1.00,1.01)  1.54µs × (1.00,1.01)   -0.89% (p=0.000)
SetTypeNode64DeadSlice  1.55µs × (1.00,1.01)  1.52µs × (1.00,1.00)   -2.23% (p=0.000)

This is the last CL in the sequence converting from the 4-bit heap
to the 2-bit heap, with all the same optimizations reenabled.
Compared to before that process began (compared to CL 9701 patch set 1):

name                    old mean              new mean              delta
BinaryTree17             5.87s × (0.94,1.09)   5.91s × (0.96,1.06)    ~    (p=0.578)
Fannkuch11               4.32s × (1.00,1.00)   4.32s × (1.00,1.00)    ~    (p=0.474)
FmtFprintfEmpty         89.1ns × (0.95,1.16)  89.0ns × (0.93,1.10)    ~    (p=0.942)
FmtFprintfString         283ns × (0.98,1.02)   298ns × (0.98,1.06)  +5.33% (p=0.000)
FmtFprintfInt            284ns × (0.98,1.04)   286ns × (0.98,1.03)    ~    (p=0.208)
FmtFprintfIntInt         486ns × (0.98,1.03)   498ns × (0.97,1.06)  +2.48% (p=0.000)
FmtFprintfPrefixedInt    400ns × (0.99,1.02)   408ns × (0.98,1.02)  +2.23% (p=0.000)
FmtFprintfFloat          566ns × (0.99,1.01)   587ns × (0.98,1.01)  +3.69% (p=0.000)
FmtManyArgs             1.91µs × (0.99,1.02)  1.94µs × (0.99,1.02)  +1.81% (p=0.000)
GobDecode               15.5ms × (0.98,1.05)  15.8ms × (0.98,1.03)  +1.94% (p=0.002)
GobEncode               11.9ms × (0.97,1.03)  12.0ms × (0.96,1.09)    ~    (p=0.263)
Gzip                     648ms × (0.99,1.01)   648ms × (0.99,1.01)    ~    (p=0.992)
Gunzip                   143ms × (1.00,1.00)   143ms × (1.00,1.01)    ~    (p=0.585)
HTTPClientServer        89.2µs × (0.99,1.02)  90.3µs × (0.98,1.01)  +1.24% (p=0.000)
JSONEncode              32.3ms × (0.97,1.06)  31.6ms × (0.99,1.01)  -2.29% (p=0.000)
JSONDecode               106ms × (0.99,1.01)   107ms × (1.00,1.01)  +0.62% (p=0.000)
Mandelbrot200           6.02ms × (1.00,1.00)  6.03ms × (1.00,1.01)    ~    (p=0.250)
GoParse                 6.57ms × (0.97,1.06)  6.53ms × (0.99,1.03)    ~    (p=0.243)
RegexpMatchEasy0_32      162ns × (1.00,1.00)   161ns × (1.00,1.01)  -0.80% (p=0.000)
RegexpMatchEasy0_1K      561ns × (0.99,1.02)   541ns × (0.99,1.01)  -3.67% (p=0.000)
RegexpMatchEasy1_32      145ns × (0.95,1.04)   138ns × (1.00,1.00)  -5.04% (p=0.000)
RegexpMatchEasy1_1K      864ns × (0.99,1.04)   887ns × (0.99,1.01)  +2.57% (p=0.000)
RegexpMatchMedium_32     255ns × (0.99,1.04)   253ns × (0.99,1.01)  -1.05% (p=0.012)
RegexpMatchMedium_1K    73.9µs × (0.98,1.04)  72.8µs × (1.00,1.00)  -1.51% (p=0.005)
RegexpMatchHard_32      3.92µs × (0.98,1.04)  3.85µs × (1.00,1.01)  -1.88% (p=0.002)
RegexpMatchHard_1K       120µs × (0.98,1.04)   117µs × (1.00,1.01)  -2.02% (p=0.001)
Revcomp                  936ms × (0.95,1.08)   922ms × (0.97,1.08)    ~    (p=0.234)
Template                 130ms × (0.98,1.04)   126ms × (0.99,1.01)  -2.99% (p=0.000)
TimeParse                638ns × (0.98,1.05)   628ns × (0.99,1.01)  -1.54% (p=0.004)
TimeFormat               674ns × (0.99,1.01)   668ns × (0.99,1.01)  -0.80% (p=0.001)

The slowdown of the first few benchmarks seems to be due to the new
atomic operations for certain small size allocations. But the larger
benchmarks mostly improve, probably due to the decreased memory
pressure from having half as much heap bitmap.

CL 9706, which removes the (never used anymore) wbshadow mode,
gets back what is lost in the early microbenchmarks.

Change-Id: I37423a209e8ec2a2e92538b45cac5422a6acd32d
Reviewed-on: https://go-review.googlesource.com/9705
Reviewed-by: Rick Hudson <rlh@golang.org>
2015-05-11 14:51:40 +00:00
api runtime: remove unused GC times from api.next 2015-05-06 14:49:26 +00:00
doc doc/effective_go: make function signature match function body 2015-05-08 17:01:24 +00:00
lib/time remove the obsolete lib/codereview. 2014-12-08 07:51:54 +00:00
misc misc/trace: add license for the trace-viewer 2015-05-11 06:09:10 +00:00
src runtime: reintroduce ``dead'' space during GC scan 2015-05-11 14:51:40 +00:00
test cmd/internal/gc: unsafe.Pointer constants may only be converted to uintptr 2015-05-07 23:54:28 +00:00
.gitattributes .gitattributes: prevent all magic line ending changes 2014-12-12 23:14:54 +00:00
.gitignore .gitignore: ignore ARM64 build products 2015-03-16 18:44:22 +00:00
AUTHORS A+C: add another email address for Emil Hessman 2014-11-12 10:01:23 -08:00
CONTRIBUTING.md doc: direct people to the mailing list 2015-01-18 21:27:07 +00:00
CONTRIBUTORS CONTRIBUTORS: add Burcu Dogan's personal mail 2015-05-06 16:06:42 +00:00
favicon.ico
LICENSE
PATENTS
README.md doc: fix broken link in README 2015-02-19 05:50:57 +00:00
robots.txt

README.md

The Go Programming Language

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

Gopher image

For documentation about how to install and use Go, visit https://golang.org/ or load doc/install-source.html in your web browser.

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.

Please report issues here: https://golang.org/issue/new

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

Please note that we do not use pull requests.

Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.

--

Binary Distribution Notes

If you have just untarred a binary Go distribution, you need to set the environment variable $GOROOT to the full path of the go directory (the one containing this file). You can omit the variable if you unpack it into /usr/local/go, or if you rebuild from sources by running all.bash (see doc/install-source.html). You should also add the Go binary directory $GOROOT/bin to your shell's path.

For example, if you extracted the tar file into $HOME/go, you might put the following in your .profile:

export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin

See https://golang.org/doc/install or doc/install.html for more details.