Bug 785237: Give prelaunch processes background priority, and move the background oom_adj up (down?) a class. r=jlebar

b2g/app/b2g.js

@@ -507,7 +507,7 @@ pref("dom.ipc.processPriorityManager.enabled", true);
 pref("dom.ipc.processPriorityManager.gracePeriodMS", 1000);
 pref("hal.processPriorityManager.gonk.masterOomAdjust", 0);
 pref("hal.processPriorityManager.gonk.foregroundOomAdjust", 1);
-pref("hal.processPriorityManager.gonk.backgroundOomAdjust", 2);
+pref("hal.processPriorityManager.gonk.backgroundOomAdjust", 6);
 pref("hal.processPriorityManager.gonk.masterNice", -1);
 pref("hal.processPriorityManager.gonk.foregroundNice", 0);
 pref("hal.processPriorityManager.gonk.backgroundNice", 10);

dom/ipc/ContentChild.cpp

@@ -19,9 +19,11 @@
 #include "AudioChild.h"
 #endif
 
+#include "mozilla/Attributes.h"
 #include "mozilla/dom/ExternalHelperAppChild.h"
 #include "mozilla/dom/PCrashReporterChild.h"
 #include "mozilla/dom/StorageChild.h"
+#include "mozilla/Hal.h"
 #include "mozilla/hal_sandbox/PHalChild.h"
 #include "mozilla/ipc/TestShellChild.h"
 #include "mozilla/ipc/XPCShellEnvironment.h"
@@ -31,7 +33,6 @@
 #include "mozilla/layers/PCompositorChild.h"
 #include "mozilla/net/NeckoChild.h"
 #include "mozilla/Preferences.h"
-#include "mozilla/Attributes.h"
 
 #if defined(MOZ_SYDNEYAUDIO)
 #include "nsAudioStream.h"
@@ -100,6 +101,7 @@
 #include "nsContentUtils.h"
 #include "nsIPrincipal.h"
 
+using namespace base;
 using namespace mozilla::docshell;
 using namespace mozilla::dom::devicestorage;
 using namespace mozilla::dom::sms;
@@ -287,6 +289,14 @@ ContentChild::Init(MessageLoop* aIOLoop,
 #endif
 #endif
 
+    bool startBackground = true;
+    SendGetProcessAttributes(&mID, &startBackground,
+                             &mIsForApp, &mIsForBrowser);
+    hal::SetProcessPriority(
+        GetCurrentProcId(),
+        startBackground ? hal::PROCESS_PRIORITY_BACKGROUND:
+                          hal::PROCESS_PRIORITY_FOREGROUND);
+
     return true;
 }
 
@@ -951,20 +961,6 @@ ContentChild::RecvAppInfo(const nsCString& version, const nsCString& buildID)
     return true;
 }
 
-bool
-ContentChild::RecvSetProcessAttributes(const uint64_t &id,
-                                       const bool& aIsForApp,
-                                       const bool& aIsForBrowser)
-{
-    if (mID != uint64_t(-1)) {
-        NS_WARNING("Setting content child's ID twice?");
-    }
-    mID = id;
-    mIsForApp = aIsForApp;
-    mIsForBrowser = aIsForBrowser;
-    return true;
-}
-
 bool
 ContentChild::RecvLastPrivateDocShellDestroyed()
 {

dom/ipc/ContentChild.h

@@ -167,9 +167,6 @@ public:
     virtual bool RecvCycleCollect();
 
     virtual bool RecvAppInfo(const nsCString& version, const nsCString& buildID);
-    virtual bool RecvSetProcessAttributes(const uint64_t& id,
-                                          const bool& aIsForApp,
-                                          const bool& aIsForBrowser);
 
     virtual bool RecvLastPrivateDocShellDestroyed();
 

dom/ipc/ContentParent.cpp

@@ -686,9 +686,10 @@ ContentParent::ContentParent(const nsAString& aAppManifestURL,
     , mGeolocationWatchID(-1)
     , mRunToCompletionDepth(0)
     , mShouldCallUnblockChild(false)
+    , mAppManifestURL(aAppManifestURL)
     , mIsAlive(true)
     , mSendPermissionUpdates(false)
-    , mAppManifestURL(aAppManifestURL)
+    , mIsForBrowser(aIsForBrowser)
 {
     // From this point on, NS_WARNING, NS_ASSERTION, etc. should print out the
     // PID along with the warning.
@@ -707,8 +708,6 @@ ContentParent::ContentParent(const nsAString& aAppManifestURL,
         mSubprocess->AsyncLaunch();
     }
     Open(mSubprocess->GetChannel(), mSubprocess->GetChildProcessHandle());
-    unused << SendSetProcessAttributes(gContentChildID++,
-                                       IsForApp(), aIsForBrowser);
 
     // NB: internally, this will send an IPC message to the child
     // process to get it to create the CompositorChild.  This
@@ -1087,6 +1086,18 @@ ContentParent::AllocPImageBridge(mozilla::ipc::Transport* aTransport,
     return ImageBridgeParent::Create(aTransport, aOtherProcess);
 }
 
+bool
+ContentParent::RecvGetProcessAttributes(uint64_t* aId, bool* aStartBackground,
+                                        bool* aIsForApp, bool* aIsForBrowser)
+{
+    *aId = gContentChildID++;
+    *aStartBackground =
+        (mAppManifestURL == MAGIC_PREALLOCATED_APP_MANIFEST_URL);
+    *aIsForApp = IsForApp();
+    *aIsForBrowser = mIsForBrowser;
+    return true;
+}
+
 PBrowserParent*
 ContentParent::AllocPBrowser(const uint32_t& aChromeFlags,
                              const bool& aIsBrowserElement, const AppId& aApp)

dom/ipc/ContentParent.h

@@ -164,6 +164,11 @@ private:
     AllocPImageBridge(mozilla::ipc::Transport* aTransport,
                       base::ProcessId aOtherProcess) MOZ_OVERRIDE;
 
+    virtual bool RecvGetProcessAttributes(uint64_t* aId,
+                                          bool* aStartBackground,
+                                          bool* aIsForApp,
+                                          bool* aIsForBrowser) MOZ_OVERRIDE;
+
     virtual PBrowserParent* AllocPBrowser(const uint32_t& aChromeFlags,
                                           const bool& aIsBrowserElement,
                                           const AppId& aApp);
@@ -297,12 +302,13 @@ private:
     // the nsIObserverService.
     nsCOMArray<nsIMemoryReporter> mMemoryReporters;
 
-    bool mIsAlive;
-    bool mSendPermissionUpdates;
-
     const nsString mAppManifestURL;
     nsRefPtr<nsFrameMessageManager> mMessageManager;
 
+    bool mIsAlive;
+    bool mSendPermissionUpdates;
+    bool mIsForBrowser;
+
     friend class CrashReporterParent;
 };
 

dom/ipc/PContent.ipdl

@@ -198,17 +198,6 @@ child:
 
     PTestShell();
 
-    /**
-     * Tell the content process some attributes of itself.  This is
-     * the first message received by content processes after startup.
-     *
-     * |id| is a unique ID among all subprocesses.  When |isForApp &&
-     * isForBrowser|, we're loading <browser> for an app.  When
-     * |isForBrowser|, we're loading <browser>.  When |!isForApp &&
-     * !isForBrowser|, we're probably loading <xul:browser remote>.
-     */
-    SetProcessAttributes(uint64_t id, bool isForApp, bool isForBrowser);
-
     RegisterChrome(ChromePackage[] packages, ResourceMapping[] resources,
                    OverrideMapping[] overrides, nsCString locale);
 
@@ -247,6 +236,21 @@ child:
     FileSystemUpdate(nsString fsName, nsString mountPoint, int32_t fsState);
 
 parent:
+    /**
+     * Tell the content process some attributes of itself.  This is
+     * among the first information queried by content processes after
+     * startup.  (The message is sync to allow the content process to
+     * control when it receives the information.)
+     *
+     * |id| is a unique ID among all subprocesses.  When |isForApp &&
+     * isForBrowser|, we're loading <browser> for an app.  When
+     * |isForBrowser|, we're loading <browser>.  When |!isForApp &&
+     * !isForBrowser|, we're probably loading <xul:browser remote>.
+     */
+    sync GetProcessAttributes()
+        returns (uint64_t id, bool startBackground,
+                 bool isForApp, bool isForBrowser);
+
     PAudio(int32_t aNumChannels, int32_t aRate, int32_t aFormat);
 
     PDeviceStorageRequest(DeviceStorageParams params);