Lower JIT thread priority
Modify the JIT thread to run at a lower priority in order to allow
UI-critical threads to get enough CPU time.
Bug: 27417985
Change-Id: I5b962a7970ae81dac9e01a8011128c538cd78e40
diff --git a/runtime/jit/jit_instrumentation.cc b/runtime/jit/jit_instrumentation.cc
index a4e40ad..46c362a 100644
--- a/runtime/jit/jit_instrumentation.cc
+++ b/runtime/jit/jit_instrumentation.cc
@@ -25,6 +25,9 @@
namespace art {
namespace jit {
+// At what priority to schedule jit threads. 9 is the lowest foreground priority on device.
+static constexpr int kJitPoolThreadPthreadPriority = 9;
+
class JitCompileTask FINAL : public Task {
public:
enum TaskKind {
@@ -92,6 +95,7 @@
// There is a DCHECK in the 'AddSamples' method to ensure the tread pool
// is not null when we instrument.
thread_pool_.reset(new ThreadPool("Jit thread pool", 1));
+ thread_pool_->SetPthreadPriority(kJitPoolThreadPthreadPriority);
thread_pool_->StartWorkers(Thread::Current());
{
// Add Jit interpreter instrumentation, tells the interpreter when
diff --git a/runtime/thread_pool.cc b/runtime/thread_pool.cc
index 5a4dfb8..2fba805 100644
--- a/runtime/thread_pool.cc
+++ b/runtime/thread_pool.cc
@@ -16,6 +16,11 @@
#include "thread_pool.h"
+#include <pthread.h>
+
+#include <sys/time.h>
+#include <sys/resource.h>
+
#include "base/bit_utils.h"
#include "base/casts.h"
#include "base/logging.h"
@@ -53,6 +58,19 @@
CHECK_PTHREAD_CALL(pthread_join, (pthread_, nullptr), "thread pool worker shutdown");
}
+void ThreadPoolWorker::SetPthreadPriority(int priority) {
+ CHECK_GE(priority, PRIO_MIN);
+ CHECK_LE(priority, PRIO_MAX);
+#if defined(__ANDROID__)
+ int result = setpriority(PRIO_PROCESS, pthread_gettid_np(pthread_), priority);
+ if (result != 0) {
+ PLOG(ERROR) << "Failed to setpriority to :" << priority;
+ }
+#else
+ UNUSED(priority);
+#endif
+}
+
void ThreadPoolWorker::Run() {
Thread* self = Thread::Current();
Task* task = nullptr;
@@ -214,4 +232,10 @@
return tasks_.size();
}
+void ThreadPool::SetPthreadPriority(int priority) {
+ for (ThreadPoolWorker* worker : threads_) {
+ worker->SetPthreadPriority(priority);
+ }
+}
+
} // namespace art
diff --git a/runtime/thread_pool.h b/runtime/thread_pool.h
index 6cd4ad3..b6c6f02 100644
--- a/runtime/thread_pool.h
+++ b/runtime/thread_pool.h
@@ -59,6 +59,9 @@
virtual ~ThreadPoolWorker();
+ // Set the "nice" priorty for this worker.
+ void SetPthreadPriority(int priority);
+
protected:
ThreadPoolWorker(ThreadPool* thread_pool, const std::string& name, size_t stack_size);
static void* Callback(void* arg) REQUIRES(!Locks::mutator_lock_);
@@ -111,6 +114,9 @@
// thread count of the thread pool.
void SetMaxActiveWorkers(size_t threads) REQUIRES(!task_queue_lock_);
+ // Set the "nice" priorty for threads in the pool.
+ void SetPthreadPriority(int priority);
+
protected:
// get a task to run, blocks if there are no tasks left
virtual Task* GetTask(Thread* self) REQUIRES(!task_queue_lock_);
