[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376

Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged

[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom
backport/pr-121243-to-release/9.0-staging

Conversation

@github-actions

@github-actionsgithub-actionsBot commented Nov 5, 2025•
edited by BrzVlad
Loading

Copy link
Copy Markdown
Contributor

Backport of #121243 to release/9.0-staging

/cc @BrzVlad

Customer Impact

  • Customer reported
  • Found internally

Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.

Regression

  • Yes
  • No

Testing

Tested on our own gc bridge tests, with scenario causing the issue.

Risk

This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.

@BrzVladBrzVlad added Servicing-consider Issue for next servicing release review area-GC-mono labels Nov 5, 2025
@dotnet-policy-service

dotnet-policy-serviceBot commented Nov 5, 2025

Copy link
Copy Markdown
Contributor

Tagging subscribers to this area: @BrzVlad
See info in area-owners.md if you want to be subscribed.

@rbhandarbhanda added this to the 9.0.12 milestone Nov 5, 2025
This was referenced Nov 5, 2025
Open
Closed
Closed
@jkoritzinskyjkoritzinsky mentioned this pull request Nov 6, 2025
Closed
@BrzVladBrzVlad added Servicing-approved Approved for servicing release and removed Servicing-consider Issue for next servicing release review labels Nov 6, 2025
@BrzVlad

BrzVlad commented Nov 6, 2025

Copy link
Copy Markdown
Member

/ba-g failures unrelated

@BrzVlad
BrzVlad merged commit 54d40cf into release/9.0-stagingNov 6, 2025
73 of 84 checks passed
@BrzVladBrzVlad mentioned this pull request Nov 10, 2025
Merged
@jkotas
jkotas deleted the backport/pr-121243-to-release/9.0-staging branch November 12, 2025 05:17
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees

No one assigned

Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects

None yet

Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization - #121376
Merged
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Nov 6, 2025
Merged
[release/9.0-staging] [mono][sgen] Add option to disable tarjan gc bridge optimization#121376
BrzVlad merged 2 commits into
release/9.0-stagingfrom 
backport/pr-121243-to-release/9.0-staging
Conversation
@github-actions
@github-actionsgithub-actionsBot
commented
Nov 5, 2025•

edited by BrzVlad

Loading

Copy link


Copy Markdown

Contributor
Backport of #121243 to release/9.0-staging
/cc @BrzVlad
Customer Impact
  •  Customer reported
  •  Found internally
Applications on maui-android can randomly crash during GC. We've had a few fixes for the tarjan bridge merged a few months ago, but there is still one more issue. The problem is caused by a specific optimization inside the tarjan gc bridge. The only workaround for a customer hitting this failure is to configure an environment variable so that their app uses a different gc bridge (which has worse performance). One customer reported that using the older gc bridge makes the application unusable due to degradation of performance. This PR allows users to opt out of a smaller optimization and keep using the tarjan gc bridge, as a workaround for .NET9.
Regression
  •  Yes
  •  No
Testing
Tested on our own gc bridge tests, with scenario causing the issue.
Risk
This PR has zero risk since it just adds support for disabling an optimization. By default, there is no change in behavior. I plan to backport to .NET10 the actual fix for this issue.
@BrzVladBrzVlad
added

Servicing-consider
Issue for next servicing release review
area-GC-mono

labels
Nov 5, 2025
@dotnet-policy-service
dotnet-policy-serviceBot
commented
Nov 5, 2025

Copy link


Copy Markdown

Contributor
Tagging subscribers to this area: @BrzVlad

See info in area-owners.md if you want to be subscribed.
@rbhandarbhanda
added this to the 9.0.12 milestone
Nov 5, 2025

This was referenced Nov 5, 2025

Open


Closed


Closed

@jkoritzinskyjkoritzinsky
mentioned this pull request
Nov 6, 2025

Closed

@BrzVladBrzVlad
added

Servicing-approved
Approved for servicing release
and removed

Servicing-consider
Issue for next servicing release review
labels
Nov 6, 2025
@BrzVlad
BrzVlad
commented
Nov 6, 2025

Copy link


Copy Markdown

Member
/ba-g failures unrelated
@BrzVlad
BrzVlad
merged commit 54d40cf
into
release/9.0-stagingNov 6, 2025

73 of 84 checks passed

@BrzVladBrzVlad
mentioned this pull request
Nov 10, 2025
 Merged

@jkotas
jkotas
deleted the

backport/pr-121243-to-release/9.0-staging

branch
November 12, 2025 05:17
@github-actionsgithub-actionsBot
locked and limited conversation to collaborators
Dec 12, 2025
Sign up for freeto subscribe to this conversation on GitHub.
Already have an account?
Sign in.


Reviewers

@BrzVladBrzVladBrzVlad approved these changes
@lambdageeklambdageekAwaiting requested review from lambdageeklambdageek is a code owner

Assignees


No one assigned


Labels

area-GC-monoServicing-approvedApproved for servicing release

Projects


None yet


Milestone

9.0.12

Development

Successfully merging this pull request may close these issues.

2 participants

@BrzVlad@rbhanda