base: Move renderer threads to the appropriate cpuset.

base/threading/platform_thread_linux.cc

Index: base/threading/platform_thread_linux.cc
diff --git a/base/threading/platform_thread_linux.cc b/base/threading/platform_thread_linux.cc
index 95ed32418ff49bdce1cfc91b846374000f62a4e3..f1c91c7aae7614991d5158ce7ba7f3ee62db4bdd 100644
--- a/base/threading/platform_thread_linux.cc
+++ b/base/threading/platform_thread_linux.cc
@@ -8,8 +8,10 @@
 #include <sched.h>
 #include <stddef.h>
 
+#include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/threading/platform_thread_internal_posix.h"
 #include "base/threading/thread_id_name_manager.h"
 #include "base/tracked_objects.h"
@@ -65,6 +67,13 @@ bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority) {
 
 }  // namespace internal
 
+namespace {
+#if !defined(OS_NACL)
+const FilePath::CharType kCpusetDirectory[] =
+    FILE_PATH_LITERAL("/sys/fs/cgroup/cpuset/chrome");

[Dmitry Torokhov, 2016/09/12 16:18:09]

I wonder if, instead of having static cpuset placement, we should not be reading
"/proc/self/cpuset" on startup and then append urgent/non-urgent to the starting
cpuset.

We should need to make sure we actually start chrome in proper cpuset first
though.

[reveman, 2016/09/16 22:16:11]

sgtm.

dtor, can you take care of starting chrome in the proper cpuset?

+#endif
+}  // namespace
+
 // static
 void PlatformThread::SetName(const std::string& name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
@@ -90,6 +99,38 @@ void PlatformThread::SetName(const std::string& name) {
 #endif  //  !defined(OS_NACL)
 }
 
+#if !defined(OS_NACL)
+// static
+void PlatformThread::SetThreadAffinity(PlatformThreadId id,
+                                       ThreadPriority priority) {
+  // Move thread into the appropriate cpuset when chrome cpuset directory
+  // exists. Threads with BACKGROUND priority are move to the "non-urgent"
+  // cpuset and threads with DISPLAY and REALTIME_AUDIO priority are moved
+  // to "urgent" cpuset.
+  FilePath cpuset_filepath(kCpusetDirectory);
+  switch (priority) {
+    case ThreadPriority::NORMAL:
+      break;
+    case ThreadPriority::BACKGROUND:
+      cpuset_filepath = cpuset_filepath.Append(FILE_PATH_LITERAL("non-urgent"));
+      break;
+    case ThreadPriority::DISPLAY:
+    case ThreadPriority::REALTIME_AUDIO:
+      cpuset_filepath = cpuset_filepath.Append(FILE_PATH_LITERAL("urgent"));
+      break;
+  }
+  if (DirectoryExists(cpuset_filepath)) {
+    FilePath tasks_filepath =
+        cpuset_filepath.Append(FILE_PATH_LITERAL("tasks"));
+    std::string tid = IntToString(id);
+    int bytes_written = WriteFile(tasks_filepath, tid.c_str(), tid.size());
+    if (bytes_written != static_cast<int>(tid.size())) {
+      DVLOG(1) << "Failed to add " << tid << " to " << tasks_filepath.value();
+    }
+  }
+}
+#endif  //  !defined(OS_NACL)
+
 void InitThreading() {}
 
 void TerminateOnThread() {}