Chromium Blog
News and developments from the open source browser project
Scheduling tasks intelligently for optimized performance
2015年4月30日木曜日
Earlier this month, Chrome began utilizing
new techniques to get pages in front of users faster
. That's an important piece of the performance story, but it's just one - what about once the page has loaded fully? That's when users want pages to animate smoothly and react quickly to their scrolls and clicks. Chrome 41 included a task scheduler for Chrome's rendering engine that ensures those high-priority tasks are handled immediately, making Chrome feel snappier and run closer to a smooth 60 frames per second.
Given that ambitious goal, Chrome has just milliseconds to produce every frame. But painting graphics to the screen isn't all that Chrome does, and there can be several different tasks contending for a single processor core. Historically Chrome handled execution of tasks, such as animating an image, responding to a click, or doing some memory operations, the same way that a bank handles a queue of customers: the first one line in is the first one handled. While this is simple and straightforward, it's not always the best for optimal performance. An urgent task, such as painting the next frame to the screen, might be added to the end of a long queue of pending tasks. The 60 frames per second goal would be lost.
Starting in Chrome 41, we've created a task scheduler integrated into the Blink rendering engine. The scheduler is capable of evaluating pending tasks and reordering them so that the most urgent tasks, such as animating and responding to a user's action, are prioritized ahead of others. Lower priority tasks, such as clearing out unused memory, are delayed until the processor has available time. In practice, this results in up to a 40% higher responsiveness to user input when Chrome is working hard to draw frames.
However, even the most advanced scheduler can't properly queue up tasks without knowing what's coming in the future. To address this, the Blink scheduler is also integrated with Chrome's graphics engine, which has precise knowledge of when Chrome will need to deprioritize other tasks in order to paint graphics to the screen. This allows the scheduler to consider lower priority tasks and schedule only those tasks that fit nicely into the otherwise "idle" time before Chrome needs to draw another frame. These tasks are handled essentially for free, with no impact on the smooth, 60 frames-per-second animations.
The latest version of Chrome scrolling a particularly challenging website, with the scheduler enabled (left) and disabled (right).
These changes demonstrate that performance isn't just about doing things faster - it's also about doing things smarter, in the right order, and at the right time. Stay tuned for more updates about how we're using Chrome's scheduler to push the bounds of performance.
Posted by Sami Kyostila and Ross McIlroy, Senior Task Masters
ラベル
$200K
1
10th birthday
4
abusive ads
1
abusive notifications
2
accessibility
3
ad blockers
1
ad blocking
2
advanced capabilities
1
android
2
anti abuse
1
anti-deception
1
background periodic sync
1
badging
1
benchmarks
1
beta
83
better ads standards
1
billing
1
birthday
4
blink
2
browser
2
browser interoperability
1
bundles
1
capabilities
6
capable web
1
cds
1
cds18
2
cds2018
1
chrome
35
chrome 81
1
chrome 83
2
chrome 84
2
chrome ads
1
chrome apps
5
Chrome dev
1
chrome dev summit
1
chrome dev summit 2018
1
chrome dev summit 2019
1
chrome developer
1
Chrome Developer Center
1
chrome developer summit
1
chrome devtools
1
Chrome extension
1
chrome extensions
3
Chrome Frame
1
Chrome lite
1
Chrome on Android
2
chrome on ios
1
Chrome on Mac
1
Chrome OS
1
chrome privacy
4
chrome releases
1
chrome security
10
chrome web store
32
chromedevtools
1
chromeframe
3
chromeos
4
chromeos.dev
1
chromium
9
cloud print
1
coalition
1
coalition for better ads
1
contact picker
1
content indexing
1
cookies
1
core web vitals
2
csrf
1
css
1
cumulative layout shift
1
custom tabs
1
dart
8
dashboard
1
Data Saver
3
Data saver desktop extension
1
day 2
1
deceptive installation
1
declarative net request api
1
design
2
developer dashboard
1
Developer Program Policy
2
developer website
1
devtools
13
digital event
1
discoverability
1
DNS-over-HTTPS
4
DoH
4
emoji
1
emscriptem
1
enterprise
1
extensions
27
Fast badging
1
faster web
1
features
1
feedback
2
field data
1
first input delay
1
Follow
1
fonts
1
form controls
1
frameworks
1
fugu
2
fund
1
funding
1
gdd
1
google earth
1
google event
1
google io 2019
1
google web developer
1
googlechrome
12
harmful ads
1
html5
11
HTTP/3
1
HTTPS
4
iframes
1
images
1
incognito
1
insecure forms
1
intent to explain
1
ios
1
ios Chrome
1
issue tracker
3
jank
1
javascript
5
lab data
1
labelling
1
largest contentful paint
1
launch
1
lazy-loading
1
lighthouse
2
linux
2
Lite Mode
2
Lite pages
1
loading interventions
1
loading optimizations
1
lock icon
1
long-tail
1
mac
1
manifest v3
2
metrics
2
microsoft edge
1
mixed forms
1
mobile
2
na
1
native client
8
native file system
1
New Features
5
notifications
1
octane
1
open web
4
origin trials
2
pagespeed insights
1
pagespeedinsights
1
passwords
1
payment handler
1
payment request
1
payments
2
performance
20
performance tools
1
permission UI
1
permissions
1
play store
1
portals
3
prefetching
1
privacy
2
privacy sandbox
4
private prefetch proxy
1
profile guided optimization
1
progressive web apps
2
Project Strobe
1
protection
1
pwa
1
QUIC
1
quieter permissions
1
releases
3
removals
1
rlz
1
root program
1
safe browsing
2
Secure DNS
2
security
36
site isolation
1
slow loading
1
sms receiver
1
spam policy
1
spdy
2
spectre
1
speed
4
ssl
2
store listing
1
strobe
2
subscription pages
1
suspicious site reporter extension
1
TCP
1
the fast and the curious
23
TLS
1
tools
1
tracing
1
transparency
1
trusted web activities
1
twa
2
user agent string
1
user data policy
1
v8
6
video
2
wasm
1
web
1
web apps
1
web assembly
2
web developers
1
web intents
1
web packaging
1
web payments
1
web platform
1
web request api
1
web vitals
1
web.dev
1
web.dev live
1
webapi
1
webassembly
1
webaudio
3
webgl
7
webkit
5
WebM
1
webmaster
1
webp
5
webrtc
6
websockets
5
webtiming
1
writable-files
1
yerba beuna center for the arts
1
Archive
2024
8月
6月
5月
4月
3月
2月
2023
11月
10月
9月
8月
6月
5月
4月
2月
2022
12月
9月
8月
6月
5月
4月
3月
2月
1月
2021
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2020
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2019
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2018
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2017
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2016
12月
11月
10月
9月
8月
6月
5月
4月
3月
2月
1月
2015
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2014
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2013
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2012
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2011
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2010
12月
11月
10月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2009
12月
11月
9月
8月
7月
6月
5月
4月
3月
2月
1月
2008
12月
11月
10月
9月
Feed
Follow @ChromiumDev
Give us feedback in our
Product Forums
.