starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

[PR #2937] Reduce InsertAttrRuns CPU usage #25163

New Issue
Open
opened 2026-01-31 09:07:42 +00:00 by claunia · 0 comments
claunia commented 2026-01-31 09:07:42 +00:00
Owner
Copy Link

Original Pull Request: https://github.com/microsoft/terminal/pull/2937

State: closed
Merged: Yes

Summary of the Pull Request

Reduces CPU usage in ATTR_ROW::InsertAttrRuns.

References

#806

PR Checklist

  • Closes The new monospaced font (#806)
  • CLA signed. If not, go over here and sign the CLA
  • Tests added/passed
  • Requires documentation to be updated
  • I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan.

Detailed Description of the Pull Request / Additional comments

I myself have experienced the slow cursor movement described in #806 . I found one hotspot is in ATTR_ROW::InsertAttrRuns. It is called many times during screen redrawing. All those vector initializing and copying consumes lots of CPU cycles.

The idea is simple: exit as quickly as possible. The original author has already done this optimization when _list.size() is 1 or 2. I took a little further and aggresive way.

I added quick exit on these following condition

  • Insert single color that is the same as the left color:
AAAAABBBBBBBCCC
     ^
AAAAAABBBBBBCCC
  • Insert single color that is the same as surrouding ones
AAAAABBBBBBBCCC
       ^
AAAAABBBBBBBCCC

I didn't change the documentation cuz I wanna hear some feedback from the team before moving on.

Validation Steps Performed

Open .vimrc with vim and see for youself. It's not really "buttery smooth" but it it whole lot better. The CPU usage is dropped by about 30%.

**Original Pull Request:** https://github.com/microsoft/terminal/pull/2937 **State:** closed **Merged:** Yes --- ## Summary of the Pull Request Reduces CPU usage in `ATTR_ROW::InsertAttrRuns`. ## References #806 <!-- Please review the items on the PR checklist before submitting--> ## PR Checklist * [X] Closes #806 * [X] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA * [ ] Tests added/passed * [ ] Requires documentation to be updated * [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. <!-- Provide a more detailed description of the PR, other things fixed or any additional comments/features here --> ## Detailed Description of the Pull Request / Additional comments I myself have experienced the slow cursor movement described in #806 . I found one hotspot is in `ATTR_ROW::InsertAttrRuns`. It is called many times during screen redrawing. All those vector initializing and copying consumes lots of CPU cycles. The idea is simple: exit as quickly as possible. The original author has already done this optimization when `_list.size()` is 1 or 2. I took a little further and aggresive way. I added quick exit on these following condition * Insert single color that is the same as the left color: ```plaintext AAAAABBBBBBBCCC ^ AAAAAABBBBBBCCC ``` * Insert single color that is the same as surrouding ones ```plaintext AAAAABBBBBBBCCC ^ AAAAABBBBBBBCCC ``` I didn't change the documentation cuz I wanna hear some feedback from the team before moving on. <!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well --> ## Validation Steps Performed Open `.vimrc` with vim and see for youself. It's not really "buttery smooth" but it it whole lot better. The CPU usage is dropped by about 30%.
claunia added the pull-request label 2026-01-31 09:07:42 +00:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label pull-request
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#25163
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?