chromeos: Add SwapSetParamter dbus message and Feature.

Add a SwapSetParameter dbus message and then add a feature
with the corresponding parameter for changing min_filelist.

BUG=chromium:1014871
TESTED=On a betty VM CrOS image.

Change-Id: I2c875d0d2963fdbc253ae1c4419e6ad6794e5de0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880966Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Commit-Queue: Brian Geffon <bgeffon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710510}

chrome/app/DEPS

@@ -12,7 +12,7 @@ include_rules = [
   "+chrome/utility/chrome_content_utility_client.h",
   "+chromeos/constants",
   "+chromeos/hugepage_text/hugepage_text.h",
-  "+chromeos/memory/kstaled.h",
+  "+chromeos/memory",
   "+components/browser_watcher",
   "+components/component_updater",
   "+components/content_settings/core/common/content_settings_pattern.h",

chrome/app/chrome_main_delegate.cc

@@ -114,6 +114,7 @@
 #include "chromeos/constants/chromeos_switches.h"
 #include "chromeos/hugepage_text/hugepage_text.h"
 #include "chromeos/memory/kstaled.h"
+#include "chromeos/memory/swap_configuration.h"
 #endif
 
 #if defined(OS_ANDROID)
@@ -601,6 +602,7 @@ void ChromeMainDelegate::PostFieldTrialInitialization() {
     heap_profiler_controller_->Start();
 
 #if defined(OS_CHROMEOS)
+    chromeos::ConfigureSwap();
     chromeos::InitializeKstaled();
 #endif
   }

chromeos/BUILD.gn

@@ -46,6 +46,8 @@ component("chromeos") {
     "hugepage_text/hugepage_text.h",
     "memory/kstaled.cc",
     "memory/kstaled.h",
+    "memory/swap_configuration.cc",
+    "memory/swap_configuration.h",
     "policy/weekly_time/time_utils.cc",
     "policy/weekly_time/time_utils.h",
     "policy/weekly_time/weekly_time.cc",

chromeos/dbus/debug_daemon/debug_daemon_client.cc

@@ -600,6 +600,19 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
                        weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   }
 
+  void SetSwapParameter(const std::string& parameter,
+                        int32_t value,
+                        DBusMethodCallback<std::string> callback) override {
+    dbus::MethodCall method_call(debugd::kDebugdInterface, "SwapSetParameter");
+    dbus::MessageWriter writer(&method_call);
+    writer.AppendString(parameter);
+    writer.AppendInt32(value);
+    debugdaemon_proxy_->CallMethod(
+        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::BindOnce(&DebugDaemonClientImpl::OnSetSwapParameter,
+                       weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
+  }
+
  protected:
   void Init(dbus::Bus* bus) override {
     debugdaemon_proxy_ =
@@ -626,6 +639,24 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
     std::move(callback).Run(std::move(routes));
   }
 
+  void OnSetSwapParameter(DBusMethodCallback<std::string> callback,
+                          dbus::Response* response) {
+    if (!response) {
+      std::move(callback).Run(base::nullopt);
+      return;
+    }
+
+    std::string res;
+    dbus::MessageReader reader(response);
+    if (!reader.PopString(&res)) {
+      LOG(ERROR) << "Received a non-string response from dbus";
+      std::move(callback).Run(base::nullopt);
+      return;
+    }
+
+    std::move(callback).Run(std::move(res));
+  }
+
   void OnGetAllLogs(GetLogsCallback callback, dbus::Response* response) {
     std::map<std::string, std::string> logs;
     bool broken = false;  // did we see a broken (k,v) pair?

chromeos/dbus/debug_daemon/debug_daemon_client.h

@@ -269,6 +269,11 @@ class COMPONENT_EXPORT(DEBUG_DAEMON) DebugDaemonClient
   virtual void GetU2fFlags(
       DBusMethodCallback<std::set<std::string>> callback) = 0;
 
+  // Set Swap Parameter
+  virtual void SetSwapParameter(const std::string& parameter,
+                                int32_t value,
+                                DBusMethodCallback<std::string> callback) = 0;
+
   // Factory function, creates a new instance and returns ownership.
   // For normal usage, access the singleton via DBusThreadManager::Get().
   static std::unique_ptr<DebugDaemonClient> Create();

chromeos/dbus/debug_daemon/fake_debug_daemon_client.cc

@@ -56,6 +56,13 @@ void FakeDebugDaemonClient::SetKstaledRatio(uint8_t val,
   std::move(callback).Run(true /* success */);
 }
 
+void FakeDebugDaemonClient::SetSwapParameter(
+    const std::string& parameter,
+    int32_t value,
+    DBusMethodCallback<std::string> callback) {
+  std::move(callback).Run(std::string());
+}
+
 std::string FakeDebugDaemonClient::GetTracingAgentName() {
   return kCrOSTracingAgentName;
 }

chromeos/dbus/debug_daemon/fake_debug_daemon_client.h

@@ -36,6 +36,9 @@ class COMPONENT_EXPORT(DEBUG_DAEMON) FakeDebugDaemonClient
                     VoidDBusMethodCallback callback) override;
   std::string GetTracingAgentName() override;
   std::string GetTraceEventLabel() override;
+  void SetSwapParameter(const std::string& parameter,
+                        int32_t value,
+                        DBusMethodCallback<std::string> callback) override;
   void StartAgentTracing(const base::trace_event::TraceConfig& trace_config,
                          StartAgentTracingCallback callback) override;
   void StopAgentTracing(StopAgentTracingCallback callback) override;

chromeos/memory/swap_configuration.cc

+// Copyright 2019 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 "chromeos/memory/swap_configuration.h"
+
+#include "base/bind.h"
+#include "base/feature_list.h"
+#include "base/metrics/field_trial_params.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/debug_daemon/debug_daemon_client.h"
+
+namespace chromeos {
+
+const base::Feature kCrOSTuneMinFilelist{"CrOSTuneMinFilelist",
+                                         base::FEATURE_DISABLED_BY_DEFAULT};
+
+const base::FeatureParam<int> kCrOSMinFilelistMb{&kCrOSTuneMinFilelist,
+                                                 "CrOSMinFilelistMb", -1};
+namespace {
+
+constexpr const char kMinFilelist[] = "min_filelist";
+
+void OnSwapParameterSet(std::string parameter,
+                        base::Optional<std::string> res) {
+  LOG_IF(ERROR, !res.has_value())
+      << "Setting swap paramter " << parameter << " failed.";
+}
+
+void ConfigureMinFilelistIfEnabled() {
+  if (!base::FeatureList::IsEnabled(kCrOSTuneMinFilelist)) {
+    return;
+  }
+
+  chromeos::DebugDaemonClient* debugd_client =
+      chromeos::DBusThreadManager::Get()->GetDebugDaemonClient();
+  CHECK(debugd_client);
+
+  int min_mb = kCrOSMinFilelistMb.Get();
+  if (min_mb < 0) {
+    LOG(ERROR) << "Min Filelist MB is enabled with an invalid value: "
+               << min_mb;
+    return;
+  }
+
+  VLOG(1) << "Setting min filelist to " << min_mb << "MB";
+  debugd_client->SetSwapParameter(
+      kMinFilelist, min_mb, base::BindOnce(&OnSwapParameterSet, kMinFilelist));
+}
+
+}  // namespace
+
+void ConfigureSwap() {
+  ConfigureMinFilelistIfEnabled();
+}
+
+}  // namespace chromeos

chromeos/memory/swap_configuration.h

+// Copyright 2019 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.
+
+#ifndef CHROMEOS_MEMORY_SWAP_CONFIGURATION_H_
+#define CHROMEOS_MEMORY_SWAP_CONFIGURATION_H_
+
+#include "base/feature_list.h"
+#include "base/metrics/field_trial_params.h"
+#include "chromeos/chromeos_export.h"
+
+namespace chromeos {
+
+// Controls the ChromeOS /proc/sys/vm/min_filelist_kb swap tunable, if the
+// feature is enabled it will use the value (in MB) from the feature param.
+extern const base::Feature kCrOSTuneMinFilelist;
+extern const base::FeatureParam<int> kCrOSTuneMinFilelistMb;
+
+// Configure swap will configure any swap related experiments that this user may
+// be opted into.
+CHROMEOS_EXPORT void ConfigureSwap();
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_MEMORY_SWAP_CONFIGURATION_H_