Skip to content

[BOLT] Support profile density with basic samples #137644

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

Merged
merged 3 commits into from
May 11, 2025
Merged

[BOLT] Support profile density with basic samples #137644

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
5854848
[𝘀𝗽𝗿] initial version
aaupov Apr 28, 2025
235390a
use RawBranchCount for basic samples as well
aaupov May 10, 2025
30b3fde
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
3 changes: 3 additions & 0 deletions bolt/include/bolt/Profile/DataReader.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -246,6 +246,9 @@ struct FuncSampleData {
/// Get the number of samples recorded in [Start, End)
uint64_t getSamples(uint64_t Start, uint64_t End) const;

/// Returns the total number of samples recorded in this function.
uint64_t getSamples() const;

/// Aggregation helper
DenseMap<uint64_t, size_t> Index;

Expand Down
23 changes: 15 additions & 8 deletions bolt/lib/Profile/DataAggregator.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -565,15 +565,14 @@ void DataAggregator::processProfile(BinaryContext &BC) {
processMemEvents();

// Mark all functions with registered events as having a valid profile.
const auto Flags = opts::BasicAggregation ? BinaryFunction::PF_SAMPLE
: BinaryFunction::PF_LBR;
for (auto &BFI : BC.getBinaryFunctions()) {
BinaryFunction &BF = BFI.second;
FuncBranchData *FBD = getBranchData(BF);
if (FBD || getFuncSampleData(BF.getNames())) {
BF.markProfiled(Flags);
if (FBD)
BF.RawBranchCount = FBD->getNumExecutedBranches();
if (FuncBranchData *FBD = getBranchData(BF)) {
BF.markProfiled(BinaryFunction::PF_LBR);
BF.RawBranchCount = FBD->getNumExecutedBranches();
} else if (FuncSampleData *FSD = getFuncSampleData(BF.getNames())) {
BF.markProfiled(BinaryFunction::PF_SAMPLE);
BF.RawBranchCount = FSD->getSamples();
}
}

Expand Down Expand Up @@ -630,10 +629,18 @@ StringRef DataAggregator::getLocationName(const BinaryFunction &Func,

bool DataAggregator::doSample(BinaryFunction &OrigFunc, uint64_t Address,
uint64_t Count) {
// To record executed bytes, use basic block size as is regardless of BAT.
uint64_t BlockSize = 0;
if (BinaryBasicBlock *BB = OrigFunc.getBasicBlockContainingOffset(
Address - OrigFunc.getAddress()))
BlockSize = BB->getOriginalSize();

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

auto I = NamesToSamples.find(Func.getOneName());
if (I == NamesToSamples.end()) {
Expand Down
7 changes: 7 additions & 0 deletions bolt/lib/Profile/DataReader.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -128,6 +128,13 @@ uint64_t FuncSampleData::getSamples(uint64_t Start, uint64_t End) const {
return Result;
}

uint64_t FuncSampleData::getSamples() const {
uint64_t Result = 0;
for (const SampleInfo &I : Data)
Result += I.Hits;
return Result;
}

void FuncSampleData::bumpCount(uint64_t Offset, uint64_t Count) {
auto Iter = Index.find(Offset);
if (Iter == Index.end()) {
Expand Down
1 change: 1 addition & 0 deletions bolt/test/perf2bolt/perf_test.test
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ RUN: perf2bolt %t -p=%t2 -o %t3 -nl -ignore-build-id 2>&1 | FileCheck %s

CHECK-NOT: PERF2BOLT-ERROR
CHECK-NOT: !! WARNING !! This high mismatch ratio indicates the input binary is probably not the same binary used during profiling collection.
CHECK: BOLT-INFO: Functions with density >= {{.*}} account for 99.00% total sample counts.

RUN: %clang %S/Inputs/perf_test.c -no-pie -fuse-ld=lld -o %t4
RUN: perf record -Fmax -e cycles:u -o %t5 -- %t4
Expand Down
Loading