Compact system processes.
Compact system processes soon after boot and during idle maintenance. This
will help keep the pagecache in a more consistent state.
Test: boots, works
bug 119988524
Change-Id: I7207d6ba3a2047278b767718dbc532e06f5516fd
diff --git a/services/core/jni/Android.bp b/services/core/jni/Android.bp
index 00b815a..a7423ea 100644
--- a/services/core/jni/Android.bp
+++ b/services/core/jni/Android.bp
@@ -50,6 +50,7 @@
"com_android_server_VibratorService.cpp",
"com_android_server_PersistentDataBlockService.cpp",
"com_android_server_GraphicsStatsService.cpp",
+ "com_android_server_am_AppCompactor.cpp",
"onload.cpp",
],
diff --git a/services/core/jni/com_android_server_am_AppCompactor.cpp b/services/core/jni/com_android_server_am_AppCompactor.cpp
new file mode 100644
index 0000000..de6aa8b
--- /dev/null
+++ b/services/core/jni/com_android_server_am_AppCompactor.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "AppCompactor"
+//#define LOG_NDEBUG 0
+
+#include <dirent.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <android-base/stringprintf.h>
+#include <android-base/file.h>
+
+#include <nativehelper/JNIHelp.h>
+#include <android_runtime/AndroidRuntime.h>
+#include <jni.h>
+
+using android::base::StringPrintf;
+using android::base::WriteStringToFile;
+
+namespace android {
+
+// This performs per-process reclaim on all processes belonging to non-app UIDs.
+// For the most part, these are non-zygote processes like Treble HALs, but it
+// also includes zygote-derived processes that run in system UIDs, like bluetooth
+// or potentially some mainline modules. The only process that should definitely
+// not be compacted is system_server, since compacting system_server around the
+// time of BOOT_COMPLETE could result in perceptible issues.
+static void com_android_server_am_AppCompactor_compactSystem(JNIEnv *, jobject) {
+ std::unique_ptr<DIR, decltype(&closedir)> proc(opendir("/proc"), closedir);
+ struct dirent* current;
+ while ((current = readdir(proc.get()))) {
+ if (current->d_type != DT_DIR) {
+ continue;
+ }
+
+ // don't compact system_server, rely on persistent compaction during screen off
+ // in order to avoid mmap_sem-related stalls
+ if (atoi(current->d_name) == getpid()) {
+ continue;
+ }
+
+ std::string status_name = StringPrintf("/proc/%s/status", current->d_name);
+ struct stat status_info;
+
+ if (stat(status_name.c_str(), &status_info) != 0) {
+ // must be some other directory that isn't a pid
+ continue;
+ }
+
+ // android.os.Process.FIRST_APPLICATION_UID
+ if (status_info.st_uid >= 10000) {
+ continue;
+ }
+
+ std::string reclaim_path = StringPrintf("/proc/%s/reclaim", current->d_name);
+ WriteStringToFile(std::string("all"), reclaim_path);
+ }
+}
+
+static const JNINativeMethod sMethods[] = {
+ /* name, signature, funcPtr */
+ {"compactSystem", "()V", (void*)com_android_server_am_AppCompactor_compactSystem},
+};
+
+int register_android_server_am_AppCompactor(JNIEnv* env)
+{
+ return jniRegisterNativeMethods(env, "com/android/server/am/AppCompactor",
+ sMethods, NELEM(sMethods));
+}
+
+}
diff --git a/services/core/jni/onload.cpp b/services/core/jni/onload.cpp
index 5ffed03..2cfaebf 100644
--- a/services/core/jni/onload.cpp
+++ b/services/core/jni/onload.cpp
@@ -54,6 +54,7 @@
int register_android_hardware_display_DisplayViewport(JNIEnv* env);
int register_android_server_net_NetworkStatsService(JNIEnv* env);
int register_android_server_security_VerityUtils(JNIEnv* env);
+int register_android_server_am_AppCompactor(JNIEnv* env);
};
using namespace android;
@@ -101,5 +102,6 @@
register_android_hardware_display_DisplayViewport(env);
register_android_server_net_NetworkStatsService(env);
register_android_server_security_VerityUtils(env);
+ register_android_server_am_AppCompactor(env);
return JNI_VERSION_1_4;
}