/*
* Copyright 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "jit_logger.h"
#include "arch/instruction_set.h"
#include "art_method-inl.h"
#include "base/time_utils.h"
#include "base/unix_file/fd_file.h"
#include "driver/compiler_driver.h"
#include "jit/jit.h"
#include "jit/jit_code_cache.h"
#include "oat_file-inl.h"
namespace art {
namespace jit {
#ifdef ART_TARGET_ANDROID
static const char* kLogPrefix = "/data/misc/trace";
#else
static const char* kLogPrefix = "/tmp";
#endif
// File format of perf-PID.map:
// +---------------------+
// |ADDR SIZE symbolname1|
// |ADDR SIZE symbolname2|
// |... |
// +---------------------+
void JitLogger::OpenPerfMapLog() {
std::string pid_str = std::to_string(getpid());
std::string perf_filename = std::string(kLogPrefix) + "/perf-" + pid_str + ".map";
perf_file_.reset(OS::CreateEmptyFileWriteOnly(perf_filename.c_str()));
if (perf_file_ == nullptr) {
LOG(ERROR) << "Could not create perf file at " << perf_filename <<
" Are you on a user build? Perf only works on userdebug/eng builds";
}
}
void JitLogger::WritePerfMapLog(const void* ptr, size_t code_size, ArtMethod* method) {
if (perf_file_ != nullptr) {
std::string method_name = method->PrettyMethod();
std::ostringstream stream;
stream << std::hex
<< reinterpret_cast<uintptr_t>(ptr)
<< " "
<< code_size
<< " "
<< method_name
<< std::endl;
std::string str = stream.str();
bool res = perf_file_->WriteFully(str.c_str(), str.size());
if (!res) {
LOG(WARNING) << "Failed to write jitted method info in log: write failure.";
}
} else {
LOG(WARNING) << "Failed to write jitted method info in log: log file doesn't exist.";
}
}
void JitLogger::ClosePerfMapLog() {
if (perf_file_ != nullptr) {
UNUSED(perf_file_->Flush());
UNUSED(perf_file_->Close());
}
}
// File format of jit-PID.jump:
//
// +--------------------------------+
// | PerfJitHeader |
// +--------------------------------+
// | PerfJitCodeLoad { | .
// | struct PerfJitBase; | .
// | uint32_t process_id_; | .
// | uint32_t thread_id_; | .
// | uint64_t vma_; | .
// | uint64_t code_address_; | .
// | uint64_t code_size_; | .
// | uint64_t code_id_; | .
// | } | .
// +- -+ .
// | method_name'\0' | +--> one jitted method
// +- -+ .
// | jitted code binary | .
// | ... | .
// +--------------------------------+ .
// | PerfJitCodeDebugInfo { | .
// | struct PerfJitBase; | .
// | uint64_t address_; | .
// | uint64_t entry_count_; | .
// | struct PerfJitDebugEntry; | .
// | } | .
// +--------------------------------+
// | PerfJitCodeLoad |
// ...
//
struct PerfJitHeader {
uint32_t magic_; // Characters "JiTD"
uint32_t version_; // Header version
uint32_t size_; // Total size of header
uint32_t elf_mach_target_; // Elf mach target
uint32_t reserved_; // Reserved, currently not used
uint32_t process_id_; // Process ID of the JIT compiler
uint64_t time_stamp_; // Timestamp when the header is generated
uint64_t flags_; // Currently the flags are only used for choosing clock for timestamp,
// we set it to 0 to tell perf that we use CLOCK_MONOTONIC clock.
static const uint32_t kMagic = 0x4A695444; // "JiTD"
static const uint32_t kVersion = 1;
};
// Each record starts with such basic information: event type, total size, and timestamp.
struct PerfJitBase {
enum PerfJitEvent {
// A jitted code load event.
// In ART JIT, it is used to log a new method is jit compiled and committed to jit-code-cache.
// Note that such kLoad event supports code cache GC in ART JIT.
// For every kLoad event recorded in jit-PID.dump and every perf sample recorded in perf.data,
// each event/sample has time stamp. In case code cache GC happens in ART JIT, and a new
// jitted method is committed to the same address of a previously deleted method,
// the time stamp information can help profiler to tell whether this sample belongs to the
// era of the first jitted method, or does it belong to the period of the second jitted method.
// JitCodeCache doesn't have to record any event on 'code delete'.
kLoad = 0,
// A jitted code move event, i,e. a jitted code moved from one address to another address.
// It helps profiler to map samples to the right symbol even when the code is moved.
// In ART JIT, this event can help log such behavior:
// A jitted method is recorded in previous kLoad event, but due to some reason,
// it is moved to another address in jit-code-cache.
kMove = 1,
// Logs debug line/column information.
kDebugInfo = 2,
// Logs JIT VM end of life event.
kClose = 3
};
uint32_t event_; // Must be one of the events defined in PerfJitEvent.
uint32_t size_; // Total size of this event record.
// For example, for kLoad event, size of the event record is:
// sizeof(PerfJitCodeLoad) + method_name.size() + compiled code size.
uint64_t time_stamp_; // Timestamp for the event.
};
// Logs a jitted code load event (kLoad).
// In ART JIT, it is used to log a new method is jit compiled and commited to jit-code-cache.
struct PerfJitCodeLoad : PerfJitBase {
uint32_t process_id_; // Process ID who performs the jit code load.
// In ART JIT, it is the pid of the JIT compiler.
uint32_t thread_id_; // Thread ID who performs the jit code load.
// In ART JIT, it is the tid of the JIT compiler.
uint64_t vma_; // Address of the code section. In ART JIT, because code_address_
// uses absolute address, this field is 0.
uint64_t code_address_; // Address where is jitted code is loaded.
uint64_t code_size_; // Size of the jitted code.
uint64_t code_id_; // Unique ID for each jitted code.
};
// This structure is for source line/column mapping.
// Currently this feature is not implemented in ART JIT yet.
struct PerfJitDebugEntry {
uint64_t address_; // Code address which maps to the line/column in source.
uint32_t line_number_; // Source line number starting at 1.
uint32_t column_; // Column discriminator, default 0.
const char name_[0]; // Followed by null-terminated name or \0xff\0 if same as previous.
};
// Logs debug line information (kDebugInfo).
// This structure is for source line/column mapping.
// Currently this feature is not implemented in ART JIT yet.
struct PerfJitCodeDebugInfo : PerfJitBase {
uint64_t address_; // Starting code address which the debug info describes.
uint64_t entry_count_; // How many instances of PerfJitDebugEntry.
PerfJitDebugEntry entries_[0]; // Followed by entry_count_ instances of PerfJitDebugEntry.
};
static uint32_t GetElfMach() {
#if defined(__arm__)
static const uint32_t kElfMachARM = 0x28;
return kElfMachARM;
#elif defined(__aarch64__)
static const uint32_t kElfMachARM64 = 0xB7;
return kElfMachARM64;
#elif defined(__i386__)
static const uint32_t kElfMachIA32 = 0x3;
return kElfMachIA32;
#elif defined(__x86_64__)
static const uint32_t kElfMachX64 = 0x3E;
return kElfMachX64;
#else
UNIMPLEMENTED(WARNING) << "Unsupported architecture in JitLogger";
return 0;
#endif
}
void JitLogger::OpenMarkerFile() {
int fd = jit_dump_file_->Fd();
// The 'perf inject' tool requires that the jit-PID.dump file
// must have a mmap(PROT_READ|PROT_EXEC) record in perf.data.
marker_address_ = mmap(nullptr, kPageSize, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
if (marker_address_ == MAP_FAILED) {
LOG(WARNING) << "Failed to create record in perf.data. JITed code profiling will not work.";
return;
}
}
void JitLogger::CloseMarkerFile() {
if (marker_address_ != nullptr) {
munmap(marker_address_, kPageSize);
}
}
void JitLogger::WriteJitDumpDebugInfo() {
// In the future, we can add java source file line/column mapping here.
}
void JitLogger::WriteJitDumpHeader() {
PerfJitHeader header;
std::memset(&header, 0, sizeof(header));
header.magic_ = PerfJitHeader::kMagic;
header.version_ = PerfJitHeader::kVersion;
header.size_ = sizeof(header);
header.elf_mach_target_ = GetElfMach();
header.process_id_ = static_cast<uint32_t>(getpid());
header.time_stamp_ = art::NanoTime(); // CLOCK_MONOTONIC clock is required.
header.flags_ = 0;
bool res = jit_dump_file_->WriteFully(reinterpret_cast<const char*>(&header), sizeof(header));
if (!res) {
LOG(WARNING) << "Failed to write profiling log. The 'perf inject' tool will not work.";
}
}
void JitLogger::OpenJitDumpLog() {
std::string pid_str = std::to_string(getpid());
std::string jitdump_filename = std::string(kLogPrefix) + "/jit-" + pid_str + ".dump";
jit_dump_file_.reset(OS::CreateEmptyFile(jitdump_filename.c_str()));
if (jit_dump_file_ == nullptr) {
LOG(ERROR) << "Could not create jit dump file at " << jitdump_filename <<
" Are you on a user build? Perf only works on userdebug/eng builds";
return;
}
OpenMarkerFile();
// Continue to write jit-PID.dump file even above OpenMarkerFile() fails.
// Even if that means 'perf inject' tool cannot work, developers can still use other tools
// to map the samples in perf.data to the information (symbol,address,code) recorded
// in the jit-PID.dump file, and still proceed the jitted code analysis.
WriteJitDumpHeader();
}
void JitLogger::WriteJitDumpLog(const void* ptr, size_t code_size, ArtMethod* method) {
if (jit_dump_file_ != nullptr) {
std::string method_name = method->PrettyMethod();
PerfJitCodeLoad jit_code;
std::memset(&jit_code, 0, sizeof(jit_code));
jit_code.event_ = PerfJitCodeLoad::kLoad;
jit_code.size_ = sizeof(jit_code) + method_name.size() + 1 + code_size;
jit_code.time_stamp_ = art::NanoTime(); // CLOCK_MONOTONIC clock is required.
jit_code.process_id_ = static_cast<uint32_t>(getpid());
jit_code.thread_id_ = static_cast<uint32_t>(art::GetTid());
jit_code.vma_ = 0x0;
jit_code.code_address_ = reinterpret_cast<uint64_t>(ptr);
jit_code.code_size_ = code_size;
jit_code.code_id_ = code_index_++;
// Write one complete jitted method info, including:
// - PerfJitCodeLoad structure
// - Method name
// - Complete generated code of this method
//
// Use UNUSED() here to avoid compiler warnings.
UNUSED(jit_dump_file_->WriteFully(reinterpret_cast<const char*>(&jit_code), sizeof(jit_code)));
UNUSED(jit_dump_file_->WriteFully(method_name.c_str(), method_name.size() + 1));
UNUSED(jit_dump_file_->WriteFully(ptr, code_size));
WriteJitDumpDebugInfo();
}
}
void JitLogger::CloseJitDumpLog() {
if (jit_dump_file_ != nullptr) {
CloseMarkerFile();
UNUSED(jit_dump_file_->Flush());
UNUSED(jit_dump_file_->Close());
}
}
} // namespace jit
} // namespace art