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[BOLT] Make memory profile parsing optional (#129585)

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Introduce `parse-mem-profile` option to limit overheads processing
tracing data (Intel PT or ARM ETM). By default, it's enabled for
perf data (existing behavior), unless `itrace` is passed to parse
tracing data where it's extremely expensive. In this case, the flag
needs to be set explicitly if needed.
This commit is contained in:
Amir Ayupov 2025-06-12 14:46:37 -07:00 committed by GitHub
parent e4c32a4147
commit 902a991e12
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GPG Key ID: B5690EEEBB952194
1 changed files with 17 additions and 8 deletions
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25
bolt/lib/Profile/DataAggregator.cpp
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@ -61,6 +61,12 @@ FilterMemProfile("filter-mem-profile",
cl::init(true),
cl::cat(AggregatorCategory));
static cl::opt<bool> ParseMemProfile(
"parse-mem-profile",
cl::desc("enable memory profile parsing if it's present in the input data, "
"on by default unless `--itrace` is set."),
cl::init(true), cl::cat(AggregatorCategory));
static cl::opt<unsigned long long>
FilterPID("pid",
cl::desc("only use samples from process with specified PID"),
@ -181,6 +187,10 @@ void DataAggregator::start() {
"script -F pid,event,ip",
/*Wait = */false);
} else if (!opts::ITraceAggregation.empty()) {
// Disable parsing memory profile from trace data, unless requested by user.
if (!opts::ParseMemProfile.getNumOccurrences())
opts::ParseMemProfile = false;
std::string ItracePerfScriptArgs = llvm::formatv(
"script -F pid,brstack --itrace={0}", opts::ITraceAggregation);
launchPerfProcess("branch events with itrace", MainEventsPPI,
@ -191,12 +201,9 @@ void DataAggregator::start() {
/*Wait = */ false);
}
// Note: we launch script for mem events regardless of the option, as the
// command fails fairly fast if mem events were not collected.
launchPerfProcess("mem events",
MemEventsPPI,
"script -F pid,event,addr,ip",
/*Wait = */false);
if (opts::ParseMemProfile)
launchPerfProcess("mem events", MemEventsPPI, "script -F pid,event,addr,ip",
/*Wait = */ false);
launchPerfProcess("process events", MMapEventsPPI,
"script --show-mmap-events --no-itrace",
@ -217,7 +224,8 @@ void DataAggregator::abort() {
sys::Wait(TaskEventsPPI.PI, 1, &Error);
sys::Wait(MMapEventsPPI.PI, 1, &Error);
sys::Wait(MainEventsPPI.PI, 1, &Error);
sys::Wait(MemEventsPPI.PI, 1, &Error);
if (opts::ParseMemProfile)
sys::Wait(MemEventsPPI.PI, 1, &Error);
deleteTempFiles();
@ -506,7 +514,8 @@ Error DataAggregator::preprocessProfile(BinaryContext &BC) {
errs() << "PERF2BOLT: failed to parse samples\n";
// Special handling for memory events
if (!prepareToParse("mem events", MemEventsPPI, MemEventsErrorCallback))
if (opts::ParseMemProfile &&
!prepareToParse("mem events", MemEventsPPI, MemEventsErrorCallback))
if (const std::error_code EC = parseMemEvents())
errs() << "PERF2BOLT: failed to parse memory events: " << EC.message()
<< '\n';