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// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <fcntl.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
#include <cstring>
#include <fstream>
#include <iostream>
#include <string>
#include <utility>
#include <vector>
#include "base/basictypes.h"
#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/containers/hash_tables.h"
#include "base/file_util.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_piece.h"
#include "base/strings/string_split.h"
#include "base/strings/stringprintf.h"
namespace {
// An entry in /proc/<pid>/pagemap.
struct PageMapEntry {
uint64 page_frame_number : 55;
uint unused : 8;
uint present : 1;
};
// Describes a virtual page.
struct PageInfo {
int64 page_frame_number : 55; // Physical page id, also known as PFN.
int64 times_mapped : 9 + 32;
};
struct MemoryMap {
std::string name;
std::string flags;
uint start_address;
uint end_address;
int private_count;
int app_shared_count;
int other_shared_count;
std::vector<PageInfo> committed_pages;
};
struct ProcessMemory {
pid_t pid;
std::vector<MemoryMap> memory_maps;
};
// Number of times a physical page is mapped in a process.
typedef base::hash_map<uint64, int> PFNMap;
// Parses lines from /proc/<PID>/maps, e.g.:
// 401e7000-401f5000 r-xp 00000000 103:02 158 /system/bin/linker
bool ParseMemoryMapLine(const std::string& line,
std::vector<std::string>* tokens,
MemoryMap* memory_map) {
tokens->clear();
base::SplitString(line, ' ', tokens);
if (tokens->size() < 2)
return false;
const int addr_len = 8;
const std::string& addr_range = tokens->at(0);
if (addr_range.length() != addr_len + 1 + addr_len)
return false;
uint64 tmp = 0;
if (!base::HexStringToUInt64(
base::StringPiece(
addr_range.begin(), addr_range.begin() + addr_len),
&tmp)) {
return false;
}
memory_map->start_address = static_cast<uint>(tmp);
const int end_addr_start_pos = addr_len + 1;
if (!base::HexStringToUInt64(
base::StringPiece(
addr_range.begin() + end_addr_start_pos,
addr_range.begin() + end_addr_start_pos + addr_len),
&tmp)) {
return false;
}
memory_map->end_address = static_cast<uint>(tmp);
if (tokens->at(1).size() != strlen("rwxp"))
return false;
memory_map->flags.swap(tokens->at(1));
const int map_name_index = 5;
if (tokens->size() >= map_name_index + 1) {
for (std::vector<std::string>::const_iterator it =
tokens->begin() + map_name_index; it != tokens->end(); ++it) {
if (!it->empty()) {
if (!memory_map->name.empty())
memory_map->name.append(" ");
memory_map->name.append(*it);
}
}
}
return true;
}
// Reads sizeof(T) bytes from file |fd| at |offset|.
template <typename T>
bool ReadFromFileAtOffset(int fd, off_t offset, T* value) {
if (lseek64(fd, offset * sizeof(*value), SEEK_SET) < 0) {
PLOG(ERROR) << "lseek";
return false;
}
ssize_t bytes = read(fd, value, sizeof(*value));
if (bytes != sizeof(*value) && bytes != 0) {
PLOG(ERROR) << "read";
return false;
}
return true;
}
// Fills |process_maps| in with the process memory maps identified by |pid|.
bool GetProcessMaps(pid_t pid, std::vector<MemoryMap>* process_maps) {
std::ifstream maps_file(base::StringPrintf("/proc/%d/maps", pid).c_str());
if (!maps_file.good()) {
PLOG(ERROR) << "open";
return false;
}
std::string line;
std::vector<std::string> tokens;
while (std::getline(maps_file, line) && !line.empty()) {
MemoryMap memory_map = {};
if (!ParseMemoryMapLine(line, &tokens, &memory_map)) {
LOG(ERROR) << "Could not parse line: " << line;
return false;
}
process_maps->push_back(memory_map);
}
return true;
}
// Fills |committed_pages| in with the set of committed pages contained in the
// provided memory map.
bool GetPagesForMemoryMap(int pagemap_fd,
const MemoryMap& memory_map,
std::vector<PageInfo>* committed_pages) {
for (uint addr = memory_map.start_address; addr < memory_map.end_address;
addr += PAGE_SIZE) {
DCHECK_EQ(0, addr % PAGE_SIZE);
PageMapEntry page_map_entry = {};
COMPILE_ASSERT(sizeof(PageMapEntry) == sizeof(uint64), unexpected_size);
const off64_t offset = addr / PAGE_SIZE;
if (!ReadFromFileAtOffset(pagemap_fd, offset, &page_map_entry))
return false;
if (page_map_entry.present) { // Ignore non-committed pages.
if (page_map_entry.page_frame_number == 0)
continue;
PageInfo page_info = {};
page_info.page_frame_number = page_map_entry.page_frame_number;
committed_pages->push_back(page_info);
}
}
return true;
}
bool SetTimesMapped(int pagecount_fd, std::vector<PageInfo>* pages) {
for (std::vector<PageInfo>::iterator it = pages->begin();
it != pages->end(); ++it) {
PageInfo* const page_info = &*it;
int64 times_mapped;
if (!ReadFromFileAtOffset(
pagecount_fd, page_info->page_frame_number, ×_mapped)) {
return false;
}
page_info->times_mapped = times_mapped;
}
return true;
}
// Fills in the provided vector of Page Frame Number maps. This lets
// ClassifyPages() know how many times each page is mapped in the processes.
void FillPFNMaps(const std::vector<ProcessMemory>& processes_memory,
std::vector<PFNMap>* pfn_maps) {
int current_process_index = 0;
for (std::vector<ProcessMemory>::const_iterator it = processes_memory.begin();
it != processes_memory.end(); ++it, ++current_process_index) {
const std::vector<MemoryMap>& memory_maps = it->memory_maps;
for (std::vector<MemoryMap>::const_iterator it = memory_maps.begin();
it != memory_maps.end(); ++it) {
const std::vector<PageInfo>& pages = it->committed_pages;
for (std::vector<PageInfo>::const_iterator it = pages.begin();
it != pages.end(); ++it) {
const PageInfo& page_info = *it;
PFNMap* const pfn_map = &(*pfn_maps)[current_process_index];
const std::pair<PFNMap::iterator, bool> result = pfn_map->insert(
std::make_pair(page_info.page_frame_number, 0));
++result.first->second;
}
}
}
}
// Sets the private_count/app_shared_count/other_shared_count fields of the
// provided memory maps for each process.
void ClassifyPages(std::vector<ProcessMemory>* processes_memory) {
std::vector<PFNMap> pfn_maps(processes_memory->size());
FillPFNMaps(*processes_memory, &pfn_maps);
// Hash set keeping track of the physical pages mapped in a single process so
// that they can be counted only once.
std::hash_set<uint64> physical_pages_mapped_in_process;
for (std::vector<ProcessMemory>::iterator it = processes_memory->begin();
it != processes_memory->end(); ++it) {
std::vector<MemoryMap>* const memory_maps = &it->memory_maps;
physical_pages_mapped_in_process.clear();
for (std::vector<MemoryMap>::iterator it = memory_maps->begin();
it != memory_maps->end(); ++it) {
MemoryMap* const memory_map = &*it;
const std::vector<PageInfo>& pages = memory_map->committed_pages;
for (std::vector<PageInfo>::const_iterator it = pages.begin();
it != pages.end(); ++it) {
const PageInfo& page_info = *it;
if (page_info.times_mapped == 1) {
++memory_map->private_count;
continue;
}
const uint64 page_frame_number = page_info.page_frame_number;
const std::pair<std::hash_set<uint64>::iterator, bool> result =
physical_pages_mapped_in_process.insert(page_frame_number);
const bool did_insert = result.second;
if (!did_insert) {
// This physical page (mapped multiple times in the same process) was
// already counted.
continue;
}
// See if the current physical page is also mapped in the other
// processes that are being analyzed.
int times_mapped = 0;
bool mapped_in_multiple_processes = false;
for (std::vector<PFNMap>::const_iterator it = pfn_maps.begin();
it != pfn_maps.end(); ++it) {
const PFNMap& pfn_map = *it;
const PFNMap::const_iterator found_it = pfn_map.find(
page_frame_number);
if (found_it == pfn_map.end())
continue;
if (times_mapped)
mapped_in_multiple_processes = true;
times_mapped += found_it->second;
}
if (times_mapped == page_info.times_mapped) {
// The physical page is only mapped in the processes that are being
// analyzed.
if (mapped_in_multiple_processes) {
++memory_map->app_shared_count;
} else {
// The physical page is mapped multiple times in the same process.
++memory_map->private_count;
}
} else {
++memory_map->other_shared_count;
}
}
}
}
}
void DumpProcessesMemoryMaps(
const std::vector<ProcessMemory>& processes_memory) {
std::string buf;
for (std::vector<ProcessMemory>::const_iterator it = processes_memory.begin();
it != processes_memory.end(); ++it) {
const ProcessMemory& process_memory = *it;
std::cout << "[ PID=" << process_memory.pid << "]" << '\n';
const std::vector<MemoryMap>& memory_maps = process_memory.memory_maps;
for (std::vector<MemoryMap>::const_iterator it = memory_maps.begin();
it != memory_maps.end(); ++it) {
const MemoryMap& memory_map = *it;
base::SStringPrintf(
&buf, "%x-%x %s private=%d shared_app=%d shared_other=%d %s\n",
memory_map.start_address,
memory_map.end_address, memory_map.flags.c_str(),
memory_map.private_count * PAGE_SIZE,
memory_map.app_shared_count * PAGE_SIZE,
memory_map.other_shared_count * PAGE_SIZE,
memory_map.name.c_str());
std::cout << buf;
}
}
}
bool CollectProcessMemoryInformation(int page_count_fd,
ProcessMemory* process_memory) {
const pid_t pid = process_memory->pid;
int pagemap_fd = open(
base::StringPrintf("/proc/%d/pagemap", pid).c_str(), O_RDONLY);
if (pagemap_fd < 0) {
PLOG(ERROR) << "open";
return false;
}
file_util::ScopedFD auto_closer(&pagemap_fd);
std::vector<MemoryMap>* const process_maps = &process_memory->memory_maps;
if (!GetProcessMaps(pid, process_maps))
return false;
for (std::vector<MemoryMap>::iterator it = process_maps->begin();
it != process_maps->end(); ++it) {
std::vector<PageInfo>* const committed_pages = &it->committed_pages;
GetPagesForMemoryMap(pagemap_fd, *it, committed_pages);
SetTimesMapped(page_count_fd, committed_pages);
}
return true;
}
void KillAll(const std::vector<pid_t>& pids, int signal_number) {
for (std::vector<pid_t>::const_iterator it = pids.begin(); it != pids.end();
++it) {
kill(*it, signal_number);
}
}
} // namespace
int main(int argc, char** argv) {
if (argc == 1) {
LOG(ERROR) << "Usage: " << argv[0] << " <PID1>... <PIDN>";
return EXIT_FAILURE;
}
std::vector<pid_t> pids;
for (const char* const* ptr = argv + 1; *ptr; ++ptr) {
pid_t pid;
if (!base::StringToInt(*ptr, &pid))
return EXIT_FAILURE;
pids.push_back(pid);
}
std::vector<ProcessMemory> processes_memory(pids.size());
{
int page_count_fd = open("/proc/kpagecount", O_RDONLY);
if (page_count_fd < 0) {
PLOG(ERROR) << "open";
return EXIT_FAILURE;
}
file_util::ScopedFD page_count_fd_closer(&page_count_fd);
base::ScopedClosureRunner auto_resume_processes(
base::Bind(&KillAll, pids, SIGCONT));
KillAll(pids, SIGSTOP);
for (std::vector<pid_t>::const_iterator it = pids.begin(); it != pids.end();
++it) {
ProcessMemory* const process_memory =
&processes_memory[it - pids.begin()];
process_memory->pid = *it;
if (!CollectProcessMemoryInformation(page_count_fd, process_memory))
return EXIT_FAILURE;
}
}
ClassifyPages(&processes_memory);
DumpProcessesMemoryMaps(processes_memory);
return EXIT_SUCCESS;
}
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