base/process/process_metrics_linux.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/process/process_metrics.h"
   6
   7 #include <dirent.h>
   8 #include <fcntl.h>
   9 #include <sys/stat.h>
  10 #include <sys/time.h>
  11 #include <sys/types.h>
  12 #include <unistd.h>
  13
  14 #include "base/files/file_util.h"
  15 #include "base/logging.h"
  16 #include "base/process/internal_linux.h"
  17 #include "base/strings/string_number_conversions.h"
  18 #include "base/strings/string_split.h"
  19 #include "base/strings/string_tokenizer.h"
  20 #include "base/strings/string_util.h"
  21 #include "base/sys_info.h"
  22 #include "base/threading/thread_restrictions.h"
  23
  24 namespace base {
  25
  26 namespace {
  27
  28 void TrimKeyValuePairs(StringPairs* pairs) {
  29   DCHECK(pairs);
  30   StringPairs& p_ref = *pairs;
  31   for (size_t i = 0; i < p_ref.size(); ++i) {
  32     TrimWhitespaceASCII(p_ref[i].first, TRIM_ALL, &p_ref[i].first);
  33     TrimWhitespaceASCII(p_ref[i].second, TRIM_ALL, &p_ref[i].second);
  34   }
  35 }
  36
  37 #if defined(OS_CHROMEOS)
  38 // Read a file with a single number string and return the number as a uint64.
  39 static uint64 ReadFileToUint64(const FilePath file) {
  40   std::string file_as_string;
  41   if (!ReadFileToString(file, &file_as_string))
  42     return 0;
  43   TrimWhitespaceASCII(file_as_string, TRIM_ALL, &file_as_string);
  44   uint64 file_as_uint64 = 0;
  45   if (!StringToUint64(file_as_string, &file_as_uint64))
  46     return 0;
  47   return file_as_uint64;
  48 }
  49 #endif
  50
  51 // Read /proc/<pid>/status and return the value for |field|, or 0 on failure.
  52 // Only works for fields in the form of "Field: value kB".
  53 size_t ReadProcStatusAndGetFieldAsSizeT(pid_t pid, const std::string& field) {
  54   std::string status;
  55   {
  56     // Synchronously reading files in /proc does not hit the disk.
  57     ThreadRestrictions::ScopedAllowIO allow_io;
  58     FilePath stat_file = internal::GetProcPidDir(pid).Append("status");
  59     if (!ReadFileToString(stat_file, &status))
  60       return 0;
  61   }
  62
  63   StringPairs pairs;
  64   SplitStringIntoKeyValuePairs(status, ':', '\n', &pairs);
  65   TrimKeyValuePairs(&pairs);
  66   for (size_t i = 0; i < pairs.size(); ++i) {
  67     const std::string& key = pairs[i].first;
  68     const std::string& value_str = pairs[i].second;
  69     if (key == field) {
  70       std::vector<std::string> split_value_str;
  71       SplitString(value_str, ' ', &split_value_str);
  72       if (split_value_str.size() != 2 || split_value_str[1] != "kB") {
  73         NOTREACHED();
  74         return 0;
  75       }
  76       size_t value;
  77       if (!StringToSizeT(split_value_str[0], &value)) {
  78         NOTREACHED();
  79         return 0;
  80       }
  81       return value;
  82     }
  83   }
  84   NOTREACHED();
  85   return 0;
  86 }
  87
  88 #if defined(OS_LINUX)
  89 // Read /proc/<pid>/sched and look for |field|. On succes, return true and
  90 // write the value for |field| into |result|.
  91 // Only works for fields in the form of "field    :     uint_value"
  92 bool ReadProcSchedAndGetFieldAsUint64(pid_t pid,
  93                                       const std::string& field,
  94                                       uint64* result) {
  95   std::string sched_data;
  96   {
  97     // Synchronously reading files in /proc does not hit the disk.
  98     ThreadRestrictions::ScopedAllowIO allow_io;
  99     FilePath sched_file = internal::GetProcPidDir(pid).Append("sched");
 100     if (!ReadFileToString(sched_file, &sched_data))
 101       return false;
 102   }
 103
 104   StringPairs pairs;
 105   SplitStringIntoKeyValuePairs(sched_data, ':', '\n', &pairs);
 106   TrimKeyValuePairs(&pairs);
 107   for (size_t i = 0; i < pairs.size(); ++i) {
 108     const std::string& key = pairs[i].first;
 109     const std::string& value_str = pairs[i].second;
 110     if (key == field) {
 111       uint64 value;
 112       if (!StringToUint64(value_str, &value))
 113         return false;
 114       *result = value;
 115       return true;
 116     }
 117   }
 118   return false;
 119 }
 120 #endif  // defined(OS_LINUX)
 121
 122 // Get the total CPU of a single process.  Return value is number of jiffies
 123 // on success or -1 on error.
 124 int GetProcessCPU(pid_t pid) {
 125   // Use /proc/<pid>/task to find all threads and parse their /stat file.
 126   FilePath task_path = internal::GetProcPidDir(pid).Append("task");
 127
 128   DIR* dir = opendir(task_path.value().c_str());
 129   if (!dir) {
 130     DPLOG(ERROR) << "opendir(" << task_path.value() << ")";
 131     return -1;
 132   }
 133
 134   int total_cpu = 0;
 135   while (struct dirent* ent = readdir(dir)) {
 136     pid_t tid = internal::ProcDirSlotToPid(ent->d_name);
 137     if (!tid)
 138       continue;
 139
 140     // Synchronously reading files in /proc does not hit the disk.
 141     ThreadRestrictions::ScopedAllowIO allow_io;
 142
 143     std::string stat;
 144     FilePath stat_path =
 145         task_path.Append(ent->d_name).Append(internal::kStatFile);
 146     if (ReadFileToString(stat_path, &stat)) {
 147       int cpu = ParseProcStatCPU(stat);
 148       if (cpu > 0)
 149         total_cpu += cpu;
 150     }
 151   }
 152   closedir(dir);
 153
 154   return total_cpu;
 155 }
 156
 157 }  // namespace
 158
 159 // static
 160 ProcessMetrics* ProcessMetrics::CreateProcessMetrics(ProcessHandle process) {
 161   return new ProcessMetrics(process);
 162 }
 163
 164 // On linux, we return vsize.
 165 size_t ProcessMetrics::GetPagefileUsage() const {
 166   return internal::ReadProcStatsAndGetFieldAsSizeT(process_,
 167                                                    internal::VM_VSIZE);
 168 }
 169
 170 // On linux, we return the high water mark of vsize.
 171 size_t ProcessMetrics::GetPeakPagefileUsage() const {
 172   return ReadProcStatusAndGetFieldAsSizeT(process_, "VmPeak") * 1024;
 173 }
 174
 175 // On linux, we return RSS.
 176 size_t ProcessMetrics::GetWorkingSetSize() const {
 177   return internal::ReadProcStatsAndGetFieldAsSizeT(process_, internal::VM_RSS) *
 178       getpagesize();
 179 }
 180
 181 // On linux, we return the high water mark of RSS.
 182 size_t ProcessMetrics::GetPeakWorkingSetSize() const {
 183   return ReadProcStatusAndGetFieldAsSizeT(process_, "VmHWM") * 1024;
 184 }
 185
 186 bool ProcessMetrics::GetMemoryBytes(size_t* private_bytes,
 187                                     size_t* shared_bytes) {
 188   WorkingSetKBytes ws_usage;
 189   if (!GetWorkingSetKBytes(&ws_usage))
 190     return false;
 191
 192   if (private_bytes)
 193     *private_bytes = ws_usage.priv * 1024;
 194
 195   if (shared_bytes)
 196     *shared_bytes = ws_usage.shared * 1024;
 197
 198   return true;
 199 }
 200
 201 bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
 202 #if defined(OS_CHROMEOS)
 203   if (GetWorkingSetKBytesTotmaps(ws_usage))
 204     return true;
 205 #endif
 206   return GetWorkingSetKBytesStatm(ws_usage);
 207 }
 208
 209 double ProcessMetrics::GetCPUUsage() {
 210   TimeTicks time = TimeTicks::Now();
 211
 212   if (last_cpu_ == 0) {
 213     // First call, just set the last values.
 214     last_cpu_time_ = time;
 215     last_cpu_ = GetProcessCPU(process_);
 216     return 0;
 217   }
 218
 219   int64 time_delta = (time - last_cpu_time_).InMicroseconds();
 220   DCHECK_NE(time_delta, 0);
 221   if (time_delta == 0)
 222     return 0;
 223
 224   int cpu = GetProcessCPU(process_);
 225
 226   // We have the number of jiffies in the time period.  Convert to percentage.
 227   // Note this means we will go *over* 100 in the case where multiple threads
 228   // are together adding to more than one CPU's worth.
 229   TimeDelta cpu_time = internal::ClockTicksToTimeDelta(cpu);
 230   TimeDelta last_cpu_time = internal::ClockTicksToTimeDelta(last_cpu_);
 231   double percentage = 100.0 * (cpu_time - last_cpu_time).InSecondsF() /
 232       TimeDelta::FromMicroseconds(time_delta).InSecondsF();
 233
 234   last_cpu_time_ = time;
 235   last_cpu_ = cpu;
 236
 237   return percentage;
 238 }
 239
 240 // To have /proc/self/io file you must enable CONFIG_TASK_IO_ACCOUNTING
 241 // in your kernel configuration.
 242 bool ProcessMetrics::GetIOCounters(IoCounters* io_counters) const {
 243   // Synchronously reading files in /proc does not hit the disk.
 244   ThreadRestrictions::ScopedAllowIO allow_io;
 245
 246   std::string proc_io_contents;
 247   FilePath io_file = internal::GetProcPidDir(process_).Append("io");
 248   if (!ReadFileToString(io_file, &proc_io_contents))
 249     return false;
 250
 251   io_counters->OtherOperationCount = 0;
 252   io_counters->OtherTransferCount = 0;
 253
 254   StringPairs pairs;
 255   SplitStringIntoKeyValuePairs(proc_io_contents, ':', '\n', &pairs);
 256   TrimKeyValuePairs(&pairs);
 257   for (size_t i = 0; i < pairs.size(); ++i) {
 258     const std::string& key = pairs[i].first;
 259     const std::string& value_str = pairs[i].second;
 260     uint64* target_counter = NULL;
 261     if (key == "syscr")
 262       target_counter = &io_counters->ReadOperationCount;
 263     else if (key == "syscw")
 264       target_counter = &io_counters->WriteOperationCount;
 265     else if (key == "rchar")
 266       target_counter = &io_counters->ReadTransferCount;
 267     else if (key == "wchar")
 268       target_counter = &io_counters->WriteTransferCount;
 269     if (!target_counter)
 270       continue;
 271     bool converted = StringToUint64(value_str, target_counter);
 272     DCHECK(converted);
 273   }
 274   return true;
 275 }
 276
 277 ProcessMetrics::ProcessMetrics(ProcessHandle process)
 278     : process_(process),
 279       last_system_time_(0),
 280 #if defined(OS_LINUX)
 281       last_absolute_idle_wakeups_(0),
 282 #endif
 283       last_cpu_(0) {
 284   processor_count_ = SysInfo::NumberOfProcessors();
 285 }
 286
 287 #if defined(OS_CHROMEOS)
 288 // Private, Shared and Proportional working set sizes are obtained from
 289 // /proc/<pid>/totmaps
 290 bool ProcessMetrics::GetWorkingSetKBytesTotmaps(WorkingSetKBytes *ws_usage)
 291   const {
 292   // The format of /proc/<pid>/totmaps is:
 293   //
 294   // Rss:                6120 kB
 295   // Pss:                3335 kB
 296   // Shared_Clean:       1008 kB
 297   // Shared_Dirty:       4012 kB
 298   // Private_Clean:         4 kB
 299   // Private_Dirty:      1096 kB
 300   // Referenced:          XXX kB
 301   // Anonymous:           XXX kB
 302   // AnonHugePages:       XXX kB
 303   // Swap:                XXX kB
 304   // Locked:              XXX kB
 305   const size_t kPssIndex = (1 * 3) + 1;
 306   const size_t kPrivate_CleanIndex = (4 * 3) + 1;
 307   const size_t kPrivate_DirtyIndex = (5 * 3) + 1;
 308   const size_t kSwapIndex = (9 * 3) + 1;
 309
 310   std::string totmaps_data;
 311   {
 312     FilePath totmaps_file = internal::GetProcPidDir(process_).Append("totmaps");
 313     ThreadRestrictions::ScopedAllowIO allow_io;
 314     bool ret = ReadFileToString(totmaps_file, &totmaps_data);
 315     if (!ret || totmaps_data.length() == 0)
 316       return false;
 317   }
 318
 319   std::vector<std::string> totmaps_fields;
 320   SplitStringAlongWhitespace(totmaps_data, &totmaps_fields);
 321
 322   DCHECK_EQ("Pss:", totmaps_fields[kPssIndex-1]);
 323   DCHECK_EQ("Private_Clean:", totmaps_fields[kPrivate_CleanIndex - 1]);
 324   DCHECK_EQ("Private_Dirty:", totmaps_fields[kPrivate_DirtyIndex - 1]);
 325   DCHECK_EQ("Swap:", totmaps_fields[kSwapIndex-1]);
 326
 327   int pss = 0;
 328   int private_clean = 0;
 329   int private_dirty = 0;
 330   int swap = 0;
 331   bool ret = true;
 332   ret &= StringToInt(totmaps_fields[kPssIndex], &pss);
 333   ret &= StringToInt(totmaps_fields[kPrivate_CleanIndex], &private_clean);
 334   ret &= StringToInt(totmaps_fields[kPrivate_DirtyIndex], &private_dirty);
 335   ret &= StringToInt(totmaps_fields[kSwapIndex], &swap);
 336
 337   // On ChromeOS swap is to zram. We count this as private / shared, as
 338   // increased swap decreases available RAM to user processes, which would
 339   // otherwise create surprising results.
 340   ws_usage->priv = private_clean + private_dirty + swap;
 341   ws_usage->shared = pss + swap;
 342   ws_usage->shareable = 0;
 343   ws_usage->swapped = swap;
 344   return ret;
 345 }
 346 #endif
 347
 348 // Private and Shared working set sizes are obtained from /proc/<pid>/statm.
 349 bool ProcessMetrics::GetWorkingSetKBytesStatm(WorkingSetKBytes* ws_usage)
 350     const {
 351   // Use statm instead of smaps because smaps is:
 352   // a) Large and slow to parse.
 353   // b) Unavailable in the SUID sandbox.
 354
 355   // First we need to get the page size, since everything is measured in pages.
 356   // For details, see: man 5 proc.
 357   const int page_size_kb = getpagesize() / 1024;
 358   if (page_size_kb <= 0)
 359     return false;
 360
 361   std::string statm;
 362   {
 363     FilePath statm_file = internal::GetProcPidDir(process_).Append("statm");
 364     // Synchronously reading files in /proc does not hit the disk.
 365     ThreadRestrictions::ScopedAllowIO allow_io;
 366     bool ret = ReadFileToString(statm_file, &statm);
 367     if (!ret || statm.length() == 0)
 368       return false;
 369   }
 370
 371   std::vector<std::string> statm_vec;
 372   SplitString(statm, ' ', &statm_vec);
 373   if (statm_vec.size() != 7)
 374     return false;  // Not the format we expect.
 375
 376   int statm_rss, statm_shared;
 377   bool ret = true;
 378   ret &= StringToInt(statm_vec[1], &statm_rss);
 379   ret &= StringToInt(statm_vec[2], &statm_shared);
 380
 381   ws_usage->priv = (statm_rss - statm_shared) * page_size_kb;
 382   ws_usage->shared = statm_shared * page_size_kb;
 383
 384   // Sharable is not calculated, as it does not provide interesting data.
 385   ws_usage->shareable = 0;
 386
 387 #if defined(OS_CHROMEOS)
 388   // Can't get swapped memory from statm.
 389   ws_usage->swapped = 0;
 390 #endif
 391
 392   return ret;
 393 }
 394
 395 size_t GetSystemCommitCharge() {
 396   SystemMemoryInfoKB meminfo;
 397   if (!GetSystemMemoryInfo(&meminfo))
 398     return 0;
 399   return meminfo.total - meminfo.free - meminfo.buffers - meminfo.cached;
 400 }
 401
 402 int ParseProcStatCPU(const std::string& input) {
 403   // |input| may be empty if the process disappeared somehow.
 404   // e.g. http://crbug.com/145811.
 405   if (input.empty())
 406     return -1;
 407
 408   size_t start = input.find_last_of(')');
 409   if (start == input.npos)
 410     return -1;
 411
 412   // Number of spaces remaining until reaching utime's index starting after the
 413   // last ')'.
 414   int num_spaces_remaining = internal::VM_UTIME - 1;
 415
 416   size_t i = start;
 417   while ((i = input.find(' ', i + 1)) != input.npos) {
 418     // Validate the assumption that there aren't any contiguous spaces
 419     // in |input| before utime.
 420     DCHECK_NE(input[i - 1], ' ');
 421     if (--num_spaces_remaining == 0) {
 422       int utime = 0;
 423       int stime = 0;
 424       if (sscanf(&input.data()[i], "%d %d", &utime, &stime) != 2)
 425         return -1;
 426
 427       return utime + stime;
 428     }
 429   }
 430
 431   return -1;
 432 }
 433
 434 const char kProcSelfExe[] = "/proc/self/exe";
 435
 436 int GetNumberOfThreads(ProcessHandle process) {
 437   return internal::ReadProcStatsAndGetFieldAsInt64(process,
 438                                                    internal::VM_NUMTHREADS);
 439 }
 440
 441 namespace {
 442
 443 // The format of /proc/diskstats is:
 444 //  Device major number
 445 //  Device minor number
 446 //  Device name
 447 //  Field  1 -- # of reads completed
 448 //      This is the total number of reads completed successfully.
 449 //  Field  2 -- # of reads merged, field 6 -- # of writes merged
 450 //      Reads and writes which are adjacent to each other may be merged for
 451 //      efficiency.  Thus two 4K reads may become one 8K read before it is
 452 //      ultimately handed to the disk, and so it will be counted (and queued)
 453 //      as only one I/O.  This field lets you know how often this was done.
 454 //  Field  3 -- # of sectors read
 455 //      This is the total number of sectors read successfully.
 456 //  Field  4 -- # of milliseconds spent reading
 457 //      This is the total number of milliseconds spent by all reads (as
 458 //      measured from __make_request() to end_that_request_last()).
 459 //  Field  5 -- # of writes completed
 460 //      This is the total number of writes completed successfully.
 461 //  Field  6 -- # of writes merged
 462 //      See the description of field 2.
 463 //  Field  7 -- # of sectors written
 464 //      This is the total number of sectors written successfully.
 465 //  Field  8 -- # of milliseconds spent writing
 466 //      This is the total number of milliseconds spent by all writes (as
 467 //      measured from __make_request() to end_that_request_last()).
 468 //  Field  9 -- # of I/Os currently in progress
 469 //      The only field that should go to zero. Incremented as requests are
 470 //      given to appropriate struct request_queue and decremented as they
 471 //      finish.
 472 //  Field 10 -- # of milliseconds spent doing I/Os
 473 //      This field increases so long as field 9 is nonzero.
 474 //  Field 11 -- weighted # of milliseconds spent doing I/Os
 475 //      This field is incremented at each I/O start, I/O completion, I/O
 476 //      merge, or read of these stats by the number of I/Os in progress
 477 //      (field 9) times the number of milliseconds spent doing I/O since the
 478 //      last update of this field.  This can provide an easy measure of both
 479 //      I/O completion time and the backlog that may be accumulating.
 480
 481 const size_t kDiskDriveName = 2;
 482 const size_t kDiskReads = 3;
 483 const size_t kDiskReadsMerged = 4;
 484 const size_t kDiskSectorsRead = 5;
 485 const size_t kDiskReadTime = 6;
 486 const size_t kDiskWrites = 7;
 487 const size_t kDiskWritesMerged = 8;
 488 const size_t kDiskSectorsWritten = 9;
 489 const size_t kDiskWriteTime = 10;
 490 const size_t kDiskIO = 11;
 491 const size_t kDiskIOTime = 12;
 492 const size_t kDiskWeightedIOTime = 13;
 493
 494 }  // namespace
 495
 496 SystemMemoryInfoKB::SystemMemoryInfoKB() {
 497   total = 0;
 498   free = 0;
 499   buffers = 0;
 500   cached = 0;
 501   active_anon = 0;
 502   inactive_anon = 0;
 503   active_file = 0;
 504   inactive_file = 0;
 505   swap_total = 0;
 506   swap_free = 0;
 507   dirty = 0;
 508
 509   pswpin = 0;
 510   pswpout = 0;
 511   pgmajfault = 0;
 512
 513 #ifdef OS_CHROMEOS
 514   shmem = 0;
 515   slab = 0;
 516   gem_objects = -1;
 517   gem_size = -1;
 518 #endif
 519 }
 520
 521 scoped_ptr<Value> SystemMemoryInfoKB::ToValue() const {
 522   scoped_ptr<DictionaryValue> res(new DictionaryValue());
 523
 524   res->SetInteger("total", total);
 525   res->SetInteger("free", free);
 526   res->SetInteger("buffers", buffers);
 527   res->SetInteger("cached", cached);
 528   res->SetInteger("active_anon", active_anon);
 529   res->SetInteger("inactive_anon", inactive_anon);
 530   res->SetInteger("active_file", active_file);
 531   res->SetInteger("inactive_file", inactive_file);
 532   res->SetInteger("swap_total", swap_total);
 533   res->SetInteger("swap_free", swap_free);
 534   res->SetInteger("swap_used", swap_total - swap_free);
 535   res->SetInteger("dirty", dirty);
 536   res->SetInteger("pswpin", pswpin);
 537   res->SetInteger("pswpout", pswpout);
 538   res->SetInteger("pgmajfault", pgmajfault);
 539 #ifdef OS_CHROMEOS
 540   res->SetInteger("shmem", shmem);
 541   res->SetInteger("slab", slab);
 542   res->SetInteger("gem_objects", gem_objects);
 543   res->SetInteger("gem_size", gem_size);
 544 #endif
 545
 546   return res.Pass();
 547 }
 548
 549 // exposed for testing
 550 bool ParseProcMeminfo(const std::string& meminfo_data,
 551                       SystemMemoryInfoKB* meminfo) {
 552   // The format of /proc/meminfo is:
 553   //
 554   // MemTotal:      8235324 kB
 555   // MemFree:       1628304 kB
 556   // Buffers:        429596 kB
 557   // Cached:        4728232 kB
 558   // ...
 559   // There is no guarantee on the ordering or position
 560   // though it doesn't appear to change very often
 561
 562   // As a basic sanity check, let's make sure we at least get non-zero
 563   // MemTotal value
 564   meminfo->total = 0;
 565
 566   std::vector<std::string> meminfo_lines;
 567   Tokenize(meminfo_data, "\n", &meminfo_lines);
 568   for (std::vector<std::string>::iterator it = meminfo_lines.begin();
 569        it != meminfo_lines.end(); ++it) {
 570     std::vector<std::string> tokens;
 571     SplitStringAlongWhitespace(*it, &tokens);
 572     // HugePages_* only has a number and no suffix so we can't rely on
 573     // there being exactly 3 tokens.
 574     if (tokens.size() <= 1) {
 575       DLOG(WARNING) << "meminfo: tokens: " << tokens.size()
 576                     << " malformed line: " << *it;
 577       continue;
 578     }
 579
 580     int* target = NULL;
 581     if (tokens[0] == "MemTotal:")
 582       target = &meminfo->total;
 583     else if (tokens[0] == "MemFree:")
 584       target = &meminfo->free;
 585     else if (tokens[0] == "Buffers:")
 586       target = &meminfo->buffers;
 587     else if (tokens[0] == "Cached:")
 588       target = &meminfo->cached;
 589     else if (tokens[0] == "Active(anon):")
 590       target = &meminfo->active_anon;
 591     else if (tokens[0] == "Inactive(anon):")
 592       target = &meminfo->inactive_anon;
 593     else if (tokens[0] == "Active(file):")
 594       target = &meminfo->active_file;
 595     else if (tokens[0] == "Inactive(file):")
 596       target = &meminfo->inactive_file;
 597     else if (tokens[0] == "SwapTotal:")
 598       target = &meminfo->swap_total;
 599     else if (tokens[0] == "SwapFree:")
 600       target = &meminfo->swap_free;
 601     else if (tokens[0] == "Dirty:")
 602       target = &meminfo->dirty;
 603 #if defined(OS_CHROMEOS)
 604     // Chrome OS has a tweaked kernel that allows us to query Shmem, which is
 605     // usually video memory otherwise invisible to the OS.
 606     else if (tokens[0] == "Shmem:")
 607       target = &meminfo->shmem;
 608     else if (tokens[0] == "Slab:")
 609       target = &meminfo->slab;
 610 #endif
 611     if (target)
 612       StringToInt(tokens[1], target);
 613   }
 614
 615   // Make sure we got a valid MemTotal.
 616   return meminfo->total > 0;
 617 }
 618
 619 // exposed for testing
 620 bool ParseProcVmstat(const std::string& vmstat_data,
 621                      SystemMemoryInfoKB* meminfo) {
 622   // The format of /proc/vmstat is:
 623   //
 624   // nr_free_pages 299878
 625   // nr_inactive_anon 239863
 626   // nr_active_anon 1318966
 627   // nr_inactive_file 2015629
 628   // ...
 629   //
 630   // We iterate through the whole file because the position of the
 631   // fields are dependent on the kernel version and configuration.
 632
 633   std::vector<std::string> vmstat_lines;
 634   Tokenize(vmstat_data, "\n", &vmstat_lines);
 635   for (std::vector<std::string>::iterator it = vmstat_lines.begin();
 636        it != vmstat_lines.end(); ++it) {
 637     std::vector<std::string> tokens;
 638     SplitString(*it, ' ', &tokens);
 639     if (tokens.size() != 2)
 640       continue;
 641
 642     if (tokens[0] == "pswpin") {
 643       StringToInt(tokens[1], &meminfo->pswpin);
 644     } else if (tokens[0] == "pswpout") {
 645       StringToInt(tokens[1], &meminfo->pswpout);
 646     } else if (tokens[0] == "pgmajfault") {
 647       StringToInt(tokens[1], &meminfo->pgmajfault);
 648     }
 649   }
 650
 651   return true;
 652 }
 653
 654 bool GetSystemMemoryInfo(SystemMemoryInfoKB* meminfo) {
 655   // Synchronously reading files in /proc and /sys are safe.
 656   ThreadRestrictions::ScopedAllowIO allow_io;
 657
 658   // Used memory is: total - free - buffers - caches
 659   FilePath meminfo_file("/proc/meminfo");
 660   std::string meminfo_data;
 661   if (!ReadFileToString(meminfo_file, &meminfo_data)) {
 662     DLOG(WARNING) << "Failed to open " << meminfo_file.value();
 663     return false;
 664   }
 665
 666   if (!ParseProcMeminfo(meminfo_data, meminfo)) {
 667     DLOG(WARNING) << "Failed to parse " << meminfo_file.value();
 668     return false;
 669   }
 670
 671 #if defined(OS_CHROMEOS)
 672   // Report on Chrome OS GEM object graphics memory. /run/debugfs_gpu is a
 673   // bind mount into /sys/kernel/debug and synchronously reading the in-memory
 674   // files in /sys is fast.
 675 #if defined(ARCH_CPU_ARM_FAMILY)
 676   FilePath geminfo_file("/run/debugfs_gpu/exynos_gem_objects");
 677 #else
 678   FilePath geminfo_file("/run/debugfs_gpu/i915_gem_objects");
 679 #endif
 680   std::string geminfo_data;
 681   meminfo->gem_objects = -1;
 682   meminfo->gem_size = -1;
 683   if (ReadFileToString(geminfo_file, &geminfo_data)) {
 684     int gem_objects = -1;
 685     long long gem_size = -1;
 686     int num_res = sscanf(geminfo_data.c_str(),
 687                          "%d objects, %lld bytes",
 688                          &gem_objects, &gem_size);
 689     if (num_res == 2) {
 690       meminfo->gem_objects = gem_objects;
 691       meminfo->gem_size = gem_size;
 692     }
 693   }
 694
 695 #if defined(ARCH_CPU_ARM_FAMILY)
 696   // Incorporate Mali graphics memory if present.
 697   FilePath mali_memory_file("/sys/class/misc/mali0/device/memory");
 698   std::string mali_memory_data;
 699   if (ReadFileToString(mali_memory_file, &mali_memory_data)) {
 700     long long mali_size = -1;
 701     int num_res = sscanf(mali_memory_data.c_str(), "%lld bytes", &mali_size);
 702     if (num_res == 1)
 703       meminfo->gem_size += mali_size;
 704   }
 705 #endif  // defined(ARCH_CPU_ARM_FAMILY)
 706 #endif  // defined(OS_CHROMEOS)
 707
 708   FilePath vmstat_file("/proc/vmstat");
 709   std::string vmstat_data;
 710   if (!ReadFileToString(vmstat_file, &vmstat_data)) {
 711     DLOG(WARNING) << "Failed to open " << vmstat_file.value();
 712     return false;
 713   }
 714   if (!ParseProcVmstat(vmstat_data, meminfo)) {
 715     DLOG(WARNING) << "Failed to parse " << vmstat_file.value();
 716     return false;
 717   }
 718
 719   return true;
 720 }
 721
 722 SystemDiskInfo::SystemDiskInfo() {
 723   reads = 0;
 724   reads_merged = 0;
 725   sectors_read = 0;
 726   read_time = 0;
 727   writes = 0;
 728   writes_merged = 0;
 729   sectors_written = 0;
 730   write_time = 0;
 731   io = 0;
 732   io_time = 0;
 733   weighted_io_time = 0;
 734 }
 735
 736 scoped_ptr<Value> SystemDiskInfo::ToValue() const {
 737   scoped_ptr<DictionaryValue> res(new DictionaryValue());
 738
 739   // Write out uint64 variables as doubles.
 740   // Note: this may discard some precision, but for JS there's no other option.
 741   res->SetDouble("reads", static_cast<double>(reads));
 742   res->SetDouble("reads_merged", static_cast<double>(reads_merged));
 743   res->SetDouble("sectors_read", static_cast<double>(sectors_read));
 744   res->SetDouble("read_time", static_cast<double>(read_time));
 745   res->SetDouble("writes", static_cast<double>(writes));
 746   res->SetDouble("writes_merged", static_cast<double>(writes_merged));
 747   res->SetDouble("sectors_written", static_cast<double>(sectors_written));
 748   res->SetDouble("write_time", static_cast<double>(write_time));
 749   res->SetDouble("io", static_cast<double>(io));
 750   res->SetDouble("io_time", static_cast<double>(io_time));
 751   res->SetDouble("weighted_io_time", static_cast<double>(weighted_io_time));
 752
 753   return res.Pass();
 754 }
 755
 756 bool IsValidDiskName(const std::string& candidate) {
 757   if (candidate.length() < 3)
 758     return false;
 759   if (candidate[1] == 'd' &&
 760       (candidate[0] == 'h' || candidate[0] == 's' || candidate[0] == 'v')) {
 761     // [hsv]d[a-z]+ case
 762     for (size_t i = 2; i < candidate.length(); ++i) {
 763       if (!islower(candidate[i]))
 764         return false;
 765     }
 766     return true;
 767   }
 768
 769   const char kMMCName[] = "mmcblk";
 770   const size_t kMMCNameLen = strlen(kMMCName);
 771   if (candidate.length() < kMMCNameLen + 1)
 772     return false;
 773   if (candidate.compare(0, kMMCNameLen, kMMCName) != 0)
 774     return false;
 775
 776   // mmcblk[0-9]+ case
 777   for (size_t i = kMMCNameLen; i < candidate.length(); ++i) {
 778     if (!isdigit(candidate[i]))
 779       return false;
 780   }
 781   return true;
 782 }
 783
 784 bool GetSystemDiskInfo(SystemDiskInfo* diskinfo) {
 785   // Synchronously reading files in /proc does not hit the disk.
 786   ThreadRestrictions::ScopedAllowIO allow_io;
 787
 788   FilePath diskinfo_file("/proc/diskstats");
 789   std::string diskinfo_data;
 790   if (!ReadFileToString(diskinfo_file, &diskinfo_data)) {
 791     DLOG(WARNING) << "Failed to open " << diskinfo_file.value();
 792     return false;
 793   }
 794
 795   std::vector<std::string> diskinfo_lines;
 796   size_t line_count = Tokenize(diskinfo_data, "\n", &diskinfo_lines);
 797   if (line_count == 0) {
 798     DLOG(WARNING) << "No lines found";
 799     return false;
 800   }
 801
 802   diskinfo->reads = 0;
 803   diskinfo->reads_merged = 0;
 804   diskinfo->sectors_read = 0;
 805   diskinfo->read_time = 0;
 806   diskinfo->writes = 0;
 807   diskinfo->writes_merged = 0;
 808   diskinfo->sectors_written = 0;
 809   diskinfo->write_time = 0;
 810   diskinfo->io = 0;
 811   diskinfo->io_time = 0;
 812   diskinfo->weighted_io_time = 0;
 813
 814   uint64 reads = 0;
 815   uint64 reads_merged = 0;
 816   uint64 sectors_read = 0;
 817   uint64 read_time = 0;
 818   uint64 writes = 0;
 819   uint64 writes_merged = 0;
 820   uint64 sectors_written = 0;
 821   uint64 write_time = 0;
 822   uint64 io = 0;
 823   uint64 io_time = 0;
 824   uint64 weighted_io_time = 0;
 825
 826   for (size_t i = 0; i < line_count; i++) {
 827     std::vector<std::string> disk_fields;
 828     SplitStringAlongWhitespace(diskinfo_lines[i], &disk_fields);
 829
 830     // Fields may have overflowed and reset to zero.
 831     if (IsValidDiskName(disk_fields[kDiskDriveName])) {
 832       StringToUint64(disk_fields[kDiskReads], &reads);
 833       StringToUint64(disk_fields[kDiskReadsMerged], &reads_merged);
 834       StringToUint64(disk_fields[kDiskSectorsRead], &sectors_read);
 835       StringToUint64(disk_fields[kDiskReadTime], &read_time);
 836       StringToUint64(disk_fields[kDiskWrites], &writes);
 837       StringToUint64(disk_fields[kDiskWritesMerged], &writes_merged);
 838       StringToUint64(disk_fields[kDiskSectorsWritten], &sectors_written);
 839       StringToUint64(disk_fields[kDiskWriteTime], &write_time);
 840       StringToUint64(disk_fields[kDiskIO], &io);
 841       StringToUint64(disk_fields[kDiskIOTime], &io_time);
 842       StringToUint64(disk_fields[kDiskWeightedIOTime], &weighted_io_time);
 843
 844       diskinfo->reads += reads;
 845       diskinfo->reads_merged += reads_merged;
 846       diskinfo->sectors_read += sectors_read;
 847       diskinfo->read_time += read_time;
 848       diskinfo->writes += writes;
 849       diskinfo->writes_merged += writes_merged;
 850       diskinfo->sectors_written += sectors_written;
 851       diskinfo->write_time += write_time;
 852       diskinfo->io += io;
 853       diskinfo->io_time += io_time;
 854       diskinfo->weighted_io_time += weighted_io_time;
 855     }
 856   }
 857
 858   return true;
 859 }
 860
 861 #if defined(OS_CHROMEOS)
 862 scoped_ptr<Value> SwapInfo::ToValue() const {
 863   scoped_ptr<DictionaryValue> res(new DictionaryValue());
 864
 865   // Write out uint64 variables as doubles.
 866   // Note: this may discard some precision, but for JS there's no other option.
 867   res->SetDouble("num_reads", static_cast<double>(num_reads));
 868   res->SetDouble("num_writes", static_cast<double>(num_writes));
 869   res->SetDouble("orig_data_size", static_cast<double>(orig_data_size));
 870   res->SetDouble("compr_data_size", static_cast<double>(compr_data_size));
 871   res->SetDouble("mem_used_total", static_cast<double>(mem_used_total));
 872   if (compr_data_size > 0)
 873     res->SetDouble("compression_ratio", static_cast<double>(orig_data_size) /
 874                                         static_cast<double>(compr_data_size));
 875   else
 876     res->SetDouble("compression_ratio", 0);
 877
 878   return res.Pass();
 879 }
 880
 881 void GetSwapInfo(SwapInfo* swap_info) {
 882   // Synchronously reading files in /sys/block/zram0 does not hit the disk.
 883   ThreadRestrictions::ScopedAllowIO allow_io;
 884
 885   FilePath zram_path("/sys/block/zram0");
 886   uint64 orig_data_size = ReadFileToUint64(zram_path.Append("orig_data_size"));
 887   if (orig_data_size <= 4096) {
 888     // A single page is compressed at startup, and has a high compression
 889     // ratio. We ignore this as it doesn't indicate any real swapping.
 890     swap_info->orig_data_size = 0;
 891     swap_info->num_reads = 0;
 892     swap_info->num_writes = 0;
 893     swap_info->compr_data_size = 0;
 894     swap_info->mem_used_total = 0;
 895     return;
 896   }
 897   swap_info->orig_data_size = orig_data_size;
 898   swap_info->num_reads = ReadFileToUint64(zram_path.Append("num_reads"));
 899   swap_info->num_writes = ReadFileToUint64(zram_path.Append("num_writes"));
 900   swap_info->compr_data_size =
 901       ReadFileToUint64(zram_path.Append("compr_data_size"));
 902   swap_info->mem_used_total =
 903       ReadFileToUint64(zram_path.Append("mem_used_total"));
 904 }
 905 #endif  // defined(OS_CHROMEOS)
 906
 907 #if defined(OS_LINUX)
 908 int ProcessMetrics::GetIdleWakeupsPerSecond() {
 909   uint64 wake_ups;
 910   const char kWakeupStat[] = "se.statistics.nr_wakeups";
 911   return ReadProcSchedAndGetFieldAsUint64(process_, kWakeupStat, &wake_ups) ?
 912       CalculateIdleWakeupsPerSecond(wake_ups) : 0;
 913 }
 914 #endif  // defined(OS_LINUX)
 915
 916 }  // namespace base