Add support for the cgroups config we have in chromeos
BUG=None
TEST=None
Review URL: http://codereview.chromium.org/6713089
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79308 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/base/process_linux.cc b/base/process_linux.cc
index 14c2424..dfdc20e 100644
--- a/base/process_linux.cc
+++ b/base/process_linux.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
@@ -7,7 +7,20 @@
#include <errno.h>
#include <sys/resource.h>
+#include "base/file_util.h"
#include "base/logging.h"
+#include "base/stringprintf.h"
+
+#if defined(OS_CHROMEOS)
+static bool use_cgroups = false;
+static bool cgroups_inited = false;
+static const char kForegroundTasks[] =
+ "/tmp/cgroup/cpu/chrome_renderers/foreground/tasks";
+static const char kBackgroundTasks[] =
+ "/tmp/cgroup/cpu/chrome_renderers/background/tasks";
+static FilePath foreground_tasks;
+static FilePath background_tasks;
+#endif
namespace base {
@@ -28,6 +41,53 @@
bool Process::SetProcessBackgrounded(bool background) {
DCHECK(process_);
+#if defined(OS_CHROMEOS)
+ // Check for cgroups files. ChromeOS supports these by default. It creates
+ // a cgroup mount in /tmp/cgroup and then configures two cpu task groups,
+ // one contains at most a single foreground renderer and the other contains
+ // all background renderers. This allows us to limit the impact of background
+ // renderers on foreground ones to a greater level than simple renicing.
+ if (!cgroups_inited) {
+ cgroups_inited = true;
+ foreground_tasks = FilePath(kForegroundTasks);
+ background_tasks = FilePath(kBackgroundTasks);
+ file_util::FileSystemType foreground_type;
+ file_util::FileSystemType background_type;
+ use_cgroups =
+ file_util::GetFileSystemType(foreground_tasks, &foreground_type) &&
+ file_util::GetFileSystemType(background_tasks, &background_type) &&
+ foreground_type == file_util::FILE_SYSTEM_CGROUP &&
+ background_type == file_util::FILE_SYSTEM_CGROUP;
+ }
+
+ if (use_cgroups) {
+ if (background) {
+ std::string pid = StringPrintf("%d", process_);
+ if (file_util::WriteFile(background_tasks, pid.c_str(), pid.size()) > 0) {
+ // With cgroups there's no real notion of priority as an int, but this
+ // will ensure we only move renderers back to the foreground group
+ // if we've ever put them in the background one.
+ saved_priority_ = 0;
+ return true;
+ } else {
+ return false;
+ }
+ } else {
+ if (saved_priority_ == kUnsetProcessPriority) {
+ // Can't restore if we were never backgrounded.
+ return false;
+ }
+ std::string pid = StringPrintf("%d", process_);
+ if (file_util::WriteFile(foreground_tasks, pid.c_str(), pid.size()) > 0) {
+ saved_priority_ = kUnsetProcessPriority;
+ return true;
+ } else {
+ return false;
+ }
+ }
+ }
+#endif // OS_CHROMEOS
+
if (background) {
// We won't be able to raise the priority if we don't have the right rlimit.
// The limit may be adjusted in /etc/security/limits.conf for PAM systems.
