Skip to content

[BOLT] Drop perf2bolt cold samples diagnostic #139337

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 2 commits into
base: users/aaupov/spr/main.bolt-drop-perf2bolt-cold-samples-diagnostic
Choose a base branch
from
Open

[BOLT] Drop perf2bolt cold samples diagnostic #139337

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
89cf9c8
[𝘀𝗽𝗿] initial version
aaupov May 9, 2025
be3f1ba
rebase
aaupov May 11, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 0 additions & 6 deletions bolt/include/bolt/Profile/DataAggregator.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -212,11 +212,6 @@ class DataAggregator : public DataReader {
uint64_t NumTraces{0};
uint64_t NumInvalidTraces{0};
uint64_t NumLongRangeTraces{0};
/// Specifies how many samples were recorded in cold areas if we are dealing
/// with profiling data collected in a bolted binary. For LBRs, incremented
/// for the source of the branch to avoid counting cold activity twice (one
/// for source and another for destination).
uint64_t NumColdSamples{0};
uint64_t NumTotalSamples{0};

/// Looks into system PATH for Linux Perf and set up the aggregator to use it
Expand Down Expand Up @@ -473,7 +468,6 @@ class DataAggregator : public DataReader {
void dump(const PerfMemSample &Sample) const;

/// Profile diagnostics print methods
void printColdSamplesDiagnostic() const;
void printLongRangeTracesDiagnostic() const;
void printBranchSamplesDiagnostics() const;
void printBasicSamplesDiagnostics(uint64_t OutOfRangeSamples) const;
Expand Down
29 changes: 3 additions & 26 deletions bolt/lib/Profile/DataAggregator.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -639,8 +639,6 @@ bool DataAggregator::doBasicSample(BinaryFunction &OrigFunc, uint64_t Address,

BinaryFunction *ParentFunc = getBATParentFunction(OrigFunc);
BinaryFunction &Func = ParentFunc ? *ParentFunc : OrigFunc;
if (ParentFunc || (BAT && !BAT->isBATFunction(Func.getAddress())))
NumColdSamples += Count;
// Attach executed bytes to parent function in case of cold fragment.
Func.SampleCountInBytes += Count * BlockSize;

Expand Down Expand Up @@ -744,15 +742,10 @@ bool DataAggregator::doBranch(uint64_t From, uint64_t To, uint64_t Count,
if (BAT)
Addr = BAT->translate(Func->getAddress(), Addr, IsFrom);

BinaryFunction *ParentFunc = getBATParentFunction(*Func);
if (IsFrom &&
(ParentFunc || (BAT && !BAT->isBATFunction(Func->getAddress()))))
NumColdSamples += Count;
if (BinaryFunction *ParentFunc = getBATParentFunction(*Func))
Func = ParentFunc;

if (!ParentFunc)
return std::pair{Func, IsRet};

return std::pair{ParentFunc, IsRet};
return std::pair{Func, IsRet};
};

auto [FromFunc, IsReturn] = handleAddress(From, /*IsFrom*/ true);
Expand Down Expand Up @@ -1452,20 +1445,6 @@ void DataAggregator::parseLBRSample(const PerfBranchSample &Sample,
}
}

void DataAggregator::printColdSamplesDiagnostic() const {
if (NumColdSamples > 0) {
const float ColdSamples = NumColdSamples * 100.0f / NumTotalSamples;
outs() << "PERF2BOLT: " << NumColdSamples
<< format(" (%.1f%%)", ColdSamples)
<< " samples recorded in cold regions of split functions.\n";
if (ColdSamples > 5.0f)
outs()
<< "WARNING: The BOLT-processed binary where samples were collected "
"likely used bad data or your service observed a large shift in "
"profile. You may want to audit this\n";
}
}

void DataAggregator::printLongRangeTracesDiagnostic() const {
outs() << "PERF2BOLT: out of range traces involving unknown regions: "
<< NumLongRangeTraces;
Expand Down Expand Up @@ -1506,7 +1485,6 @@ void DataAggregator::printBranchSamplesDiagnostics() const {
"collection. The generated data may be ineffective for improving "
"performance\n\n";
printLongRangeTracesDiagnostic();
printColdSamplesDiagnostic();
}

void DataAggregator::printBasicSamplesDiagnostics(
Expand All @@ -1518,7 +1496,6 @@ void DataAggregator::printBasicSamplesDiagnostics(
"binary is probably not the same binary used during profiling "
"collection. The generated data may be ineffective for improving "
"performance\n\n";
printColdSamplesDiagnostic();
}

void DataAggregator::printBranchStacksDiagnostics(
Expand Down
Loading