[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
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MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

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/azp run runtime-nativeaot-outerloop

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
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@filipnavara@MichalStrehovsky@LakshanF
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all
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}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
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[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
@MichalStrehovsky

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

@MichalStrehovsky

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/azp run runtime-nativeaot-outerloop

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Azure Pipelines successfully started running 1 pipeline(s).

@MichalStrehovsky

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
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@filipnavara@MichalStrehovsky@LakshanF
, '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

[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

Conversation

@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
@MichalStrehovsky

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

@MichalStrehovsky

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/azp run runtime-nativeaot-outerloop

@azure-pipelines

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Azure Pipelines successfully started running 1 pipeline(s).

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

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4 participants

@filipnavara@MichalStrehovsky@LakshanF
, '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('^' + ".*" + '
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[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
@MichalStrehovsky

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

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/azp run runtime-nativeaot-outerloop

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Azure Pipelines successfully started running 1 pipeline(s).

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

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4 participants

@filipnavara@MichalStrehovsky@LakshanF
, '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" + '
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[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

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/azp run runtime-nativeaot-outerloop

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
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@filipnavara@MichalStrehovsky@LakshanF
, '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

[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
@MichalStrehovsky

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

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/azp run runtime-nativeaot-outerloop

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Azure Pipelines successfully started running 1 pipeline(s).

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
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@filipnavara@MichalStrehovsky@LakshanF
, '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

[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
@MichalStrehovsky

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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

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/azp run runtime-nativeaot-outerloop

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Azure Pipelines successfully started running 1 pipeline(s).

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
@github-actionsgithub-actionsBot locked and limited conversation to collaborators Jul 5, 2025
Sign up for freeto subscribe to this conversation on GitHub. Already have an account? Sign in.

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Successfully merging this pull request may close these issues.

4 participants

@filipnavara@MichalStrehovsky@LakshanF
, '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

[NativeAOT] Add sampling profiler - #108083

Merged
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling
Jun 4, 2025
Merged

[NativeAOT] Add sampling profiler#108083
MichalStrehovsky merged 2 commits into
dotnet:mainfrom
filipnavara:aot-sampling

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@filipnavara

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Presumably this is pretty useless since we don't do the rundown to get readable method names... but since I already have it laying around, anyone can think of a use for this?

@dotnet-policy-servicedotnet-policy-serviceBot added the community-contribution Indicates that the PR has been added by a community member label Sep 20, 2024
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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

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@LakshanF do you think we'd be able to implement the rest?

If there is a rundown for this, we do have names of methods available in stack trace metadata. If the rundown can run managed code, we could get it there. Maybe. Depending on what actually involves the rundown.

@filipnavara

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I only tried to run it with dotnet-trace and conversion to Speedscope format, which was quite useless, since you could see the stack traces but instead of method names there was just "?!?". I wonder if PerfView could perhaps show the addresses or correlate that to image base addresses. That would be already good enough for tools that can perform native symbolication (eg. Sentry).

Stack trace metadata sound like an interesting thing to try...

@LakshanF

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There is a work item in the diagnostic repo to lookup type information for native AOT GCDump, which could be expanded to include method information as well.

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Draft Pull Request was automatically closed for 30 days of inactivity. Please let us know if you'd like to reopen it.

@github-actionsgithub-actionsBot locked and limited conversation to collaborators Dec 1, 2024
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This is useful on its own - without this, dotnet-gcdump will just hang at "Flushing the type table".

@dotnetdotnet unlocked this conversation Jun 4, 2025
@MichalStrehovsky
MichalStrehovsky marked this pull request as ready for review June 4, 2025 05:29
CopilotAI review requested due to automatic review settings June 4, 2025 05:29
@MichalStrehovsky
MichalStrehovsky self-requested a review as a code ownerJune 4, 2025 05:29

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Thank you!

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Pull Request Overview

This PR introduces a basic sampling profiler for NativeAOT by adding helper methods and integrating stack walking logic.

  • Added a new GetTransitionFrameForSampling method in thread.h
  • Extended the sampling event capture logic in ep-rt-aot.cpp
  • Introduced a GetControlPC method in StackFrameIterator.h

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

FileDescription
src/coreclr/nativeaot/Runtime/thread.hAdded a helper method to support sampling profiler functionality
src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cppIntegrated sampling profiler logic to capture stack frames and emit events
src/coreclr/nativeaot/Runtime/StackFrameIterator.hExposed the control PC via a new method for use by the profiler
Comments suppressed due to low confidence (3)

src/coreclr/nativeaot/Runtime/thread.h:323

  • Consider adding a brief comment to clarify the purpose and usage of GetTransitionFrameForSampling for future maintainability.
PInvokeTransitionFrame* GetTransitionFrameForSampling() { return GetTransitionFrame(); }

src/coreclr/nativeaot/Runtime/eventpipe/ep-rt-aot.cpp:113

  • [nitpick] Clarify or document in a tracking issue whether the differentiation between managed and external code will be addressed later to improve future code maintainability.
 // TODO: We can actually detect whether we are in managed or external code but does it matter?!

src/coreclr/nativeaot/Runtime/StackFrameIterator.h:58

  • Consider adding a comment to describe the role of GetControlPC in the sampling process to aid future maintainers.
PTR_VOID GetControlPC() { return m_ControlPC; }

@MichalStrehovsky

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/azp run runtime-nativeaot-outerloop

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@MichalStrehovsky

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/ba-g the arm32 build break was fixed and the rest are known

@MichalStrehovsky
MichalStrehovsky merged commit 3427e5f into dotnet:mainJun 4, 2025
@filipnavara
filipnavara deleted the aot-sampling branch June 4, 2025 21:01
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@filipnavara@MichalStrehovsky@LakshanF