Revert "[cpu-profiler] Log OSR code when starting the profiler"

This reverts commit f6965281.

Reason for revert: Test is flaky: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64/39092

Original change's description:
> [cpu-profiler] Log OSR code when starting the profiler
> 
> OSR code doesn't hang off any JSFunction or SFI, so we missed it when
> starting up the profiler. This meant we didn't properly attribute
> ticks to SFI code. The ticks ended up going to the caller instead.
> 
> There is a weak cache of OSR code per native context, so iterate that
> on profiler startup and log all the code objects.
> 
> Change-Id: I2e9738b86a488b37f36ac89803561607dc76f745
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414216
> Commit-Queue: Peter Marshall <petermarshall@chromium.org>
> Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Mythri Alle <mythria@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69964}

TBR=mythria@chromium.org,petermarshall@chromium.org,dinfuehr@chromium.org

Change-Id: I1e69f8af88d901bab6f257652d3536d24a4777f9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2415994Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69969}

src/heap/heap.h

@@ -1528,8 +1528,6 @@ class Heap {
 
   static Isolate* GetIsolateFromWritableObject(HeapObject object);
 
-  std::vector<Handle<NativeContext>> FindAllNativeContexts();
-
  private:
   using ExternalStringTableUpdaterCallback = String (*)(Heap* heap,
                                                         FullObjectSlot pointer);
@@ -2021,6 +2019,7 @@ class Heap {
   V8_EXPORT_PRIVATE void IncrementObjectCounters();
 #endif  // DEBUG
 
+  std::vector<Handle<NativeContext>> FindAllNativeContexts();
   std::vector<WeakArrayList> FindAllRetainedMaps();
   MemoryMeasurement* memory_measurement() { return memory_measurement_.get(); }
 

src/logging/log.cc

@@ -31,7 +31,6 @@
 #include "src/logging/log-inl.h"
 #include "src/logging/log-utils.h"
 #include "src/objects/api-callbacks.h"
-#include "src/objects/osr-optimized-code-cache.h"
 #include "src/profiler/tick-sample.h"
 #include "src/snapshot/embedded/embedded-data.h"
 #include "src/strings/string-stream.h"
@@ -1896,17 +1895,6 @@ static int EnumerateCompiledFunctions(Heap* heap,
     }
   }
 
-  for (Handle<NativeContext> native_context : heap->FindAllNativeContexts()) {
-    OSROptimizedCodeCache::Iterator osr_iterator(native_context);
-    for (std::pair<SharedFunctionInfo, Code> sfiCodePair = osr_iterator.Next();
-         !sfiCodePair.first.is_null(); sfiCodePair = osr_iterator.Next()) {
-      AddFunctionAndCode(sfiCodePair.first,
-                         AbstractCode::cast(sfiCodePair.second), sfis,
-                         code_objects, compiled_funcs_count);
-      ++compiled_funcs_count;
-    }
-  }
-
   return compiled_funcs_count;
 }
 

src/objects/osr-optimized-code-cache.cc

@@ -219,24 +219,5 @@ bool OSROptimizedCodeCache::NeedsTrimming(int num_valid_entries,
   return curr_length > kInitialLength && curr_length > num_valid_entries * 3;
 }
 
-OSROptimizedCodeCache::Iterator::Iterator(Handle<NativeContext> native_context)
-    : cache_(native_context->GetOSROptimizedCodeCache(),
-             native_context->GetIsolate()) {}
-
-std::pair<SharedFunctionInfo, Code> OSROptimizedCodeCache::Iterator::Next() {
-  while (index_ < cache_->length()) {
-    if (cache_->Get(index_ + kSharedOffset)->IsCleared() ||
-        cache_->Get(index_ + kCachedCodeOffset)->IsCleared()) {
-      index_ += kEntryLength;
-      continue;
-    }
-    auto result = std::make_pair(cache_->GetSFIFromEntry(index_),
-                                 cache_->GetCodeFromEntry(index_));
-    index_ += kEntryLength;
-    return result;
-  }
-  return std::make_pair(SharedFunctionInfo(), Code());
-}
-
 }  // namespace internal
 }  // namespace v8

src/objects/osr-optimized-code-cache.h

@@ -48,19 +48,6 @@ class V8_EXPORT OSROptimizedCodeCache : public WeakFixedArray {
   // Remove all code objects marked for deoptimization from OSR code cache.
   void EvictMarkedCode(Isolate* isolate);
 
-  // Iterate over all entries in the cache, skipping cleared or null entries.
-  class Iterator {
-   public:
-    explicit Iterator(Handle<NativeContext> native_context);
-
-    // Both results will be null when iteration has finished.
-    std::pair<SharedFunctionInfo, Code> Next();
-
-   private:
-    Handle<OSROptimizedCodeCache> cache_;
-    int index_ = 0;  // Index into the FixedArray; a multiple of kEntryLength.
-  };
-
  private:
   // Functions that implement heuristics on when to grow / shrink the cache.
   static int CapacityForLength(int curr_capacity);

test/cctest/test-cpu-profiler.cc

@@ -2241,7 +2241,10 @@ static const char* pre_profiling_osr_script = R"(
   )";
 
 // Testing profiling of OSR code that was OSR optimized before profiling
-// started.
+// started. Currently the behavior is not quite right so we're currently
+// testing a deopt event being sent to the sampling thread for a function
+// it knows nothing about. This deopt does mean we start getting samples
+// for hot so we expect some samples, just fewer than for notHot.
 //
 // We should get something like:
 //     0  (root):0 3 0 #1
@@ -2250,6 +2253,15 @@ static const char* pre_profiling_osr_script = R"(
 //    85      hot:5 0 4 #6
 //     0      whenPass:2 0 4 #3
 //     0        startProfiling:0 2 0 #4
+//
+// But currently get something like:
+//     0  (root):0 3 0 #1
+//    12    (garbage collector):0 3 0 #5
+//    57    notHot:22 0 4 #2
+//    33      hot:5 0 4 #6
+//     0      whenPass:2 0 4 #3
+//     0        startProfiling:0 2 0 #4
+
 TEST(StartProfilingAfterOsr) {
   i::FLAG_allow_natives_syntax = true;
   v8::HandleScope scope(CcTest::isolate());
@@ -2272,8 +2284,10 @@ TEST(StartProfilingAfterOsr) {
   const CpuProfileNode* root = profile->GetTopDownRoot();
   const v8::CpuProfileNode* notHotNode = GetChild(env, root, "notHot");
   const v8::CpuProfileNode* hotNode = GetChild(env, notHotNode, "hot");
-
-  CHECK_GT(hotNode->GetHitCount(), notHotNode->GetHitCount());
+  USE(hotNode);
+  // If/when OSR sampling is fixed the following CHECK_GT could/should be
+  // uncommented and the node = node line deleted.
+  // CHECK_GT(hotNode->GetHitCount(), notHotNode->GetHitCount());
 }
 
 TEST(DontStopOnFinishedProfileDelete) {