commit f044c229e12f1d49b7024ab5d7353b2d83335501
author Mathieu Chartier <mathieuc@google.com> Wed May 31 15:27:54 2017 -0700
committer Mathieu Chartier <mathieuc@google.com> Wed May 31 20:46:50 2017 -0700
tree 010bc946819a5190b19fbf55f50bef75ef789991
parent 854461a4cd5e4a38debe3616e12b52fe7f160782

Add access flag for previously warm methods

We want to know if the method was warm instead of just having a non
zero counter. This is required if we want to not compile all of the
startup methods, but still compile warm methods.

Test: test-art-host ART_TEST_JIT=true

Bug: 62200509

Change-Id: I6e04866f39f970b04b47342b7af5ed474e1f4172

runtime/jit/jit_code_cache.cc

diff --git a/runtime/jit/jit_code_cache.cc b/runtime/jit/jit_code_cache.cc
index 42d7653..fdac24e 100644
--- a/runtime/jit/jit_code_cache.cc
+++ b/runtime/jit/jit_code_cache.cc
@@ -526,6 +526,15 @@
   }
 }
 
+static void ClearMethodCounter(ArtMethod* method, bool was_warm) {
+  if (was_warm) {
+    method->AddAccessFlags(kAccPreviouslyWarm);
+  }
+  // We reset the counter to 1 so that the profile knows that the method was executed at least once.
+  // This is required for layout purposes.
+  method->SetCounter(1);
+}
+
 uint8_t* JitCodeCache::CommitCodeInternal(Thread* self,
                                           ArtMethod* method,
                                           uint8_t* stack_map,
@@ -600,7 +609,7 @@
         // Simply discard the compiled code. Clear the counter so that it may be recompiled later.
         // Hopefully the class hierarchy will be more stable when compilation is retried.
         single_impl_still_valid = false;
-        method->SetCounter(1);
+        ClearMethodCounter(method, /*was_warm*/ false);
         break;
       }
     }
@@ -1068,9 +1077,8 @@
         if (info->GetSavedEntryPoint() != nullptr) {
           info->SetSavedEntryPoint(nullptr);
           // We are going to move this method back to interpreter. Clear the counter now to
-          // give it a chance to be hot again, but set it to 1 so that this method can still be
-          // considered a startup method in case it's not executed again.
-          info->GetMethod()->SetCounter(1);
+          // give it a chance to be hot again.
+          ClearMethodCounter(info->GetMethod(), /*was_warm*/ true);
         }
       }
     } else if (kIsDebugBuild) {
@@ -1379,7 +1387,7 @@
     VLOG(jit) << method->PrettyMethod() << " needs a ProfilingInfo to be compiled";
     // Because the counter is not atomic, there are some rare cases where we may not hit the
     // threshold for creating the ProfilingInfo. Reset the counter now to "correct" this.
-    method->SetCounter(1);
+    ClearMethodCounter(method, /*was_warm*/ false);
     return false;
   }
 
@@ -1432,11 +1440,10 @@
 
   if (method->GetEntryPointFromQuickCompiledCode() == header->GetEntryPoint()) {
     // The entrypoint is the one to invalidate, so we just update it to the interpreter entry point
-    // and clear the counter to get the method Jitted again. We reset the counter to 1 to preserve
-    // it as a potential startup method.
+    // and clear the counter to get the method Jitted again.
     Runtime::Current()->GetInstrumentation()->UpdateMethodsCode(
         method, GetQuickToInterpreterBridge());
-    method->SetCounter(1);
+    ClearMethodCounter(method, /*was_warm*/ profiling_info != nullptr);
   } else {
     MutexLock mu(Thread::Current(), lock_);
     auto it = osr_code_map_.find(method);