Lower daemons priority to 124 (art).
To avoid jank.
(chery picked from commit 38a57ef702964b82836f89a1f996aff4d1453d94)
Bug: 36631902
Test: boot marlin oc-dev and check priorities.
Test: test-art-host
Change-Id: I8f809fbf5ac9605f656884fcf68643c87f22d154
diff --git a/runtime/native/dalvik_system_VMRuntime.cc b/runtime/native/dalvik_system_VMRuntime.cc
index d81c13d..6ca951f 100644
--- a/runtime/native/dalvik_system_VMRuntime.cc
+++ b/runtime/native/dalvik_system_VMRuntime.cc
@@ -17,6 +17,8 @@
#include "dalvik_system_VMRuntime.h"
#ifdef ART_TARGET_ANDROID
+#include <sys/time.h>
+#include <sys/resource.h>
extern "C" void android_set_application_target_sdk_version(uint32_t version);
#endif
#include <limits.h>
@@ -625,6 +627,23 @@
return Runtime::Current()->GetPrunedDalvikCache() ? JNI_TRUE : JNI_FALSE;
}
+static void VMRuntime_setSystemDaemonThreadPriority(JNIEnv* env ATTRIBUTE_UNUSED,
+ jclass klass ATTRIBUTE_UNUSED) {
+#ifdef ART_TARGET_ANDROID
+ Thread* self = Thread::Current();
+ DCHECK(self != nullptr);
+ pid_t tid = self->GetTid();
+ // We use a priority lower than the default for the system daemon threads (eg HeapTaskDaemon) to
+ // avoid jank due to CPU contentions between GC and other UI-related threads. b/36631902.
+ // We may use a native priority that doesn't have a corresponding java.lang.Thread-level priority.
+ static constexpr int kSystemDaemonNiceValue = 4; // priority 124
+ if (setpriority(PRIO_PROCESS, tid, kSystemDaemonNiceValue) != 0) {
+ PLOG(INFO) << *self << " setpriority(PRIO_PROCESS, " << tid << ", "
+ << kSystemDaemonNiceValue << ") failed";
+ }
+#endif
+}
+
static JNINativeMethod gMethods[] = {
FAST_NATIVE_METHOD(VMRuntime, addressOf, "(Ljava/lang/Object;)J"),
NATIVE_METHOD(VMRuntime, bootClassPath, "()Ljava/lang/String;"),
@@ -662,6 +681,7 @@
NATIVE_METHOD(VMRuntime, isBootClassPathOnDisk, "(Ljava/lang/String;)Z"),
NATIVE_METHOD(VMRuntime, getCurrentInstructionSet, "()Ljava/lang/String;"),
NATIVE_METHOD(VMRuntime, didPruneDalvikCache, "()Z"),
+ NATIVE_METHOD(VMRuntime, setSystemDaemonThreadPriority, "()V"),
};
void register_dalvik_system_VMRuntime(JNIEnv* env) {