Revert "ART: Give JIT thread pool workers a peer"

This reverts commit 1ee6dd71e1b9e51e15aae4d3bc95d799f11dbd04.

Has unintended consequences that need to be discussed.

Bug: 31684920
Change-Id: If0ff1b5d7473f98cb3a0efc3b4bb2c0f96ad684d

diff --git a/runtime/jit/jit.cc b/runtime/jit/jit.cc
index fec3c4f..6deb03d 100644 (file)
--- a/runtime/jit/jit.cc
+++ b/runtime/jit/jit.cc
@@ -145,12 +145,7 @@ Jit::Jit() : dump_info_on_shutdown_(false),
              cumulative_timings_("JIT timings"),
              memory_use_("Memory used for compilation", 16),
              lock_("JIT memory use lock"),
-             use_jit_compilation_(true),
-             hot_method_threshold_(0),
-             warm_method_threshold_(0),
-             osr_method_threshold_(0),
-             priority_thread_weight_(0),
-             invoke_transition_weight_(0) {}
+             use_jit_compilation_(true) {}
 
 Jit* Jit::Create(JitOptions* options, std::string* error_msg) {
   DCHECK(options->UseJitCompilation() || options->GetProfileSaverOptions().IsEnabled());
@@ -294,11 +289,7 @@ bool Jit::CompileMethod(ArtMethod* method, Thread* self, bool osr) {
 void Jit::CreateThreadPool() {
   // There is a DCHECK in the 'AddSamples' method to ensure the tread pool
   // is not null when we instrument.
-
-  // We need peers as we may report the JIT thread, e.g., in the debugger.
-  constexpr bool kJitPoolNeedsPeers = true;
-  thread_pool_.reset(new ThreadPool("Jit thread pool", 1, kJitPoolNeedsPeers));
-
+  thread_pool_.reset(new ThreadPool("Jit thread pool", 1));
   thread_pool_->SetPthreadPriority(kJitPoolThreadPthreadPriority);
   Start();
 }

diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index b079349..5e008a8 100644 (file)
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -671,6 +671,24 @@ bool Runtime::Start() {
 
   started_ = true;
 
+  // Create the JIT either if we have to use JIT compilation or save profiling info.
+  // TODO(calin): We use the JIT class as a proxy for JIT compilation and for
+  // recoding profiles. Maybe we should consider changing the name to be more clear it's
+  // not only about compiling. b/28295073.
+  if (jit_options_->UseJitCompilation() || jit_options_->GetSaveProfilingInfo()) {
+    std::string error_msg;
+    if (!IsZygote()) {
+    // If we are the zygote then we need to wait until after forking to create the code cache
+    // due to SELinux restrictions on r/w/x memory regions.
+      CreateJit();
+    } else if (jit_options_->UseJitCompilation()) {
+      if (!jit::Jit::LoadCompilerLibrary(&error_msg)) {
+        // Try to load compiler pre zygote to reduce PSS. b/27744947
+        LOG(WARNING) << "Failed to load JIT compiler with error " << error_msg;
+      }
+    }
+  }
+
   if (!IsImageDex2OatEnabled() || !GetHeap()->HasBootImageSpace()) {
     ScopedObjectAccess soa(self);
     StackHandleScope<2> hs(soa.Self());
@@ -695,27 +713,6 @@ bool Runtime::Start() {
 
   Thread::FinishStartup();
 
-  // Create the JIT either if we have to use JIT compilation or save profiling info. This is
-  // done after FinishStartup as the JIT pool needs Java thread peers, which require the main
-  // ThreadGroup to exist.
-  //
-  // TODO(calin): We use the JIT class as a proxy for JIT compilation and for
-  // recoding profiles. Maybe we should consider changing the name to be more clear it's
-  // not only about compiling. b/28295073.
-  if (jit_options_->UseJitCompilation() || jit_options_->GetSaveProfilingInfo()) {
-    std::string error_msg;
-    if (!IsZygote()) {
-    // If we are the zygote then we need to wait until after forking to create the code cache
-    // due to SELinux restrictions on r/w/x memory regions.
-      CreateJit();
-    } else if (jit_options_->UseJitCompilation()) {
-      if (!jit::Jit::LoadCompilerLibrary(&error_msg)) {
-        // Try to load compiler pre zygote to reduce PSS. b/27744947
-        LOG(WARNING) << "Failed to load JIT compiler with error " << error_msg;
-      }
-    }
-  }
-
   // Send the start phase event. We have to wait till here as this is when the main thread peer
   // has just been generated, important root clinits have been run and JNI is completely functional.
   {