964053d56f
This change aims at supporting LBR only sample perf script which is used for regular(Non-CS) profile generation. A LBR perf script includes a batch of LBR sample which starts with a frame pointer and a group of 32 LBR entries is followed. The FROM/TO LBR pair and the range between two consecutive entries (the former entry's TO and the latter entry's FROM) will be used to infer function profile info.
An example of LBR perf script(created by `perf script -F ip,brstack -i perf.data`)
```
40062f 0x40062f/0x4005b0/P/-/-/9 0x400645/0x4005ff/P/-/-/1 0x400637/0x400645/P/-/-/1 ...
4005d7 0x4005d7/0x4005e5/P/-/-/8 0x40062f/0x4005b0/P/-/-/6 0x400645/0x4005ff/P/-/-/1 ...
...
```
For implementation:
- Extended a new child class `LBRPerfReader` for the sample parsing, reused all the functionalities in `extractLBRStack` except for an extension to parsing leading instruction pointer.
- `HybridSample` is reused(just leave the call stack empty) and the parsed samples is still aggregated in `AggregatedSamples`. After that, range samples, branch sample, address samples are computed and recorded.
- Reused `ContextSampleCounterMap` to store the raw profile, since it's no need to aggregation by context, here it just registered one sample counter with a fake context key.
- Unified to use `show-raw-profile` instead of `show-unwinder-output` to dump the intermediate raw profile, see the comments of the format of the raw profile. For CS profile, it remains to output the unwinder output.
Profile generation part will come soon.
Differential Revision: https://reviews.llvm.org/D108153
109 lines
3.7 KiB
C++
109 lines
3.7 KiB
C++
//===- llvm-profgen.cpp - LLVM SPGO profile generation tool -----*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// llvm-profgen generates SPGO profiles from perf script ouput.
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//
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//===----------------------------------------------------------------------===//
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#include "ErrorHandling.h"
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#include "PerfReader.h"
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#include "ProfileGenerator.h"
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#include "ProfiledBinary.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/InitLLVM.h"
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#include "llvm/Support/TargetSelect.h"
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static cl::OptionCategory ProfGenCategory("ProfGen Options");
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static cl::list<std::string> PerfTraceFilenames(
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"perfscript", cl::value_desc("perfscript"), cl::OneOrMore,
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llvm::cl::MiscFlags::CommaSeparated,
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cl::desc("Path of perf-script trace created by Linux perf tool with "
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"`script` command(the raw perf.data should be profiled with -b)"),
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cl::cat(ProfGenCategory));
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static cl::opt<std::string> BinaryPath(
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"binary", cl::value_desc("binary"), cl::Required,
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cl::desc("Path of profiled binary, only one binary is supported."),
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cl::cat(ProfGenCategory));
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extern cl::opt<bool> ShowDisassemblyOnly;
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extern cl::opt<bool> ShowSourceLocations;
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extern cl::opt<bool> SkipSymbolization;
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using namespace llvm;
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using namespace sampleprof;
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// Validate the command line input.
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static void validateCommandLine(StringRef BinaryPath,
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cl::list<std::string> &PerfTraceFilenames) {
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// Allow the invalid perfscript if we only use to show binary disassembly.
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if (!ShowDisassemblyOnly) {
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for (auto &File : PerfTraceFilenames) {
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if (!llvm::sys::fs::exists(File)) {
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std::string Msg = "Input perf script(" + File + ") doesn't exist!";
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exitWithError(Msg);
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}
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}
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}
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if (!llvm::sys::fs::exists(BinaryPath)) {
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std::string Msg = "Input binary(" + BinaryPath.str() + ") doesn't exist!";
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exitWithError(Msg);
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}
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if (CSProfileGenerator::MaxCompressionSize < -1) {
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exitWithError("Value of --compress-recursion should >= -1");
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}
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if (ShowSourceLocations && !ShowDisassemblyOnly) {
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exitWithError("--show-source-locations should work together with "
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"--show-disassembly-only!");
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}
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}
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int main(int argc, const char *argv[]) {
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InitLLVM X(argc, argv);
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// Initialize targets and assembly printers/parsers.
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InitializeAllTargetInfos();
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InitializeAllTargetMCs();
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InitializeAllDisassemblers();
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cl::HideUnrelatedOptions({&ProfGenCategory, &getColorCategory()});
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cl::ParseCommandLineOptions(argc, argv, "llvm SPGO profile generator\n");
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validateCommandLine(BinaryPath, PerfTraceFilenames);
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// Load symbols and disassemble the code of a given binary.
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std::unique_ptr<ProfiledBinary> Binary =
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std::make_unique<ProfiledBinary>(BinaryPath);
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if (ShowDisassemblyOnly)
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return EXIT_SUCCESS;
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// Parse perf events and samples
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std::unique_ptr<PerfReaderBase> Reader =
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PerfReaderBase::create(Binary.get(), PerfTraceFilenames);
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Reader->parsePerfTraces(PerfTraceFilenames);
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if (SkipSymbolization)
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return EXIT_SUCCESS;
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// TBD
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if (Reader->getPerfScriptType() == PERF_LBR) {
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WithColor::warning() << "Currently LBR only perf script is not supported!";
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return EXIT_SUCCESS;
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}
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std::unique_ptr<ProfileGenerator> Generator = ProfileGenerator::create(
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Binary.get(), Reader->getSampleCounters(), Reader->getPerfScriptType());
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Generator->generateProfile();
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Generator->write();
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return EXIT_SUCCESS;
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}
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