Bug 1301764 - Implement JS_GC_REPORT_TENURING to report what is getting tenured, r=terrence

--HG--
extra : rebase_source : f1be2ad91b5848470fe486894ee7105fcc12c7bf

js/src/gc/Nursery.cpp

@@ -120,6 +120,7 @@ js::Nursery::Nursery(JSRuntime* rt)
   , previousPromotionRate_(0)
   , profileThreshold_(0)
   , enableProfiling_(false)
+  , reportTenurings_(0)
   , minorGcCount_(0)
   , freeMallocedBuffersTask(nullptr)
   , sweepActions_(nullptr)
@@ -159,13 +160,23 @@ js::Nursery::init(uint32_t maxNurseryBytes, AutoLockGC& lock)
     if (env) {
         if (0 == strcmp(env, "help")) {
             fprintf(stderr, "JS_GC_PROFILE_NURSERY=N\n"
-                    "\tReport minor GC's taking more than N microseconds.\n");
+                    "\tReport minor GC's taking at least N microseconds.\n");
             exit(0);
         }
         enableProfiling_ = true;
         profileThreshold_ = atoi(env);
     }
 
+    env = getenv("JS_GC_REPORT_TENURING");
+    if (env) {
+        if (0 == strcmp(env, "help")) {
+            fprintf(stderr, "JS_GC_REPORT_TENURING=N\n"
+                    "\tAfter a minor GC, report any ObjectGroups with at least N instances tenured.\n");
+            exit(0);
+        }
+        reportTenurings_ = atoi(env);
+    }
+
     PodZero(&startTimes_);
     PodZero(&profileTimes_);
     PodZero(&totalTimes_);
@@ -577,8 +588,7 @@ js::Nursery::collect(JSRuntime* rt, JS::gcreason::Reason reason)
     uint32_t pretenureCount = 0;
     if (promotionRate > 0.8 || reason == JS::gcreason::FULL_STORE_BUFFER) {
         JSContext* cx = rt->contextFromMainThread();
-        for (size_t i = 0; i < ArrayLength(tenureCounts.entries); i++) {
-            const TenureCount& entry = tenureCounts.entries[i];
+        for (auto& entry : tenureCounts.entries) {
             if (entry.count >= 3000) {
                 ObjectGroup* group = entry.group;
                 if (group->canPreTenure()) {
@@ -623,6 +633,15 @@ js::Nursery::collect(JSRuntime* rt, JS::gcreason::Reason reason)
                 promotionRate * 100,
                 numChunks());
         printProfileTimes(profileTimes_);
+
+        if (reportTenurings_) {
+            for (auto& entry : tenureCounts.entries) {
+                if (entry.count >= reportTenurings_) {
+                    fprintf(stderr, "%d x ", entry.count);
+                    entry.group->print();
+                }
+            }
+        }
     }
 }
 

js/src/gc/Nursery.h

@@ -305,10 +305,13 @@ class Nursery
     /* Promotion rate for the previous minor collection. */
     double previousPromotionRate_;
 
-    /* Report minor collections taking more than this many us, if enabled. */
+    /* Report minor collections taking at least this many us, if enabled. */
     int64_t profileThreshold_;
     bool enableProfiling_;
 
+    /* Report ObjectGroups with at lest this many instances tenured. */
+    int64_t reportTenurings_;
+
     /* Profiling data. */
 
     enum class ProfileKey

js/src/vm/TypeInference.cpp

@@ -123,6 +123,33 @@ TypeSet::NonObjectTypeString(TypeSet::Type type)
     return "object";
 }
 
+/* static */ const char*
+TypeSet::TypeString(TypeSet::Type type)
+{
+    if (type.isPrimitive() || type.isUnknown() || type.isAnyObject())
+        return NonObjectTypeString(type);
+
+    static char bufs[4][40];
+    static unsigned which = 0;
+    which = (which + 1) & 3;
+
+    if (type.isSingleton()) {
+        JSObject* singleton = type.singletonNoBarrier();
+        snprintf(bufs[which], 40, "<%s %#" PRIxPTR ">",
+                 singleton->getClass()->name, uintptr_t(singleton));
+    } else {
+        snprintf(bufs[which], 40, "[%s * %#" PRIxPTR "]", type.groupNoBarrier()->clasp()->name, uintptr_t(type.groupNoBarrier()));
+    }
+
+    return bufs[which];
+}
+
+/* static */ const char*
+TypeSet::ObjectGroupString(ObjectGroup* group)
+{
+    return TypeString(TypeSet::ObjectType(group));
+}
+
 #ifdef DEBUG
 
 static bool InferSpewActive(SpewChannel channel)
@@ -195,30 +222,6 @@ js::InferSpewColor(TypeSet* types)
     return colors[DefaultHasher<TypeSet*>::hash(types) % 7];
 }
 
-/* static */ const char*
-TypeSet::TypeString(TypeSet::Type type)
-{
-    if (type.isPrimitive() || type.isUnknown() || type.isAnyObject())
-        return NonObjectTypeString(type);
-
-    static char bufs[4][40];
-    static unsigned which = 0;
-    which = (which + 1) & 3;
-
-    if (type.isSingleton())
-        snprintf(bufs[which], 40, "<0x%p>", (void*) type.singletonNoBarrier());
-    else
-        snprintf(bufs[which], 40, "[0x%p]", (void*) type.groupNoBarrier());
-
-    return bufs[which];
-}
-
-/* static */ const char*
-TypeSet::ObjectGroupString(ObjectGroup* group)
-{
-    return TypeString(TypeSet::ObjectType(group));
-}
-
 void
 js::InferSpew(SpewChannel channel, const char* fmt, ...)
 {
@@ -3045,8 +3048,8 @@ ObjectGroup::print()
             fprintf(stderr, "\n    newScript %d properties",
                     (int) newScript()->templateObject()->slotSpan());
             if (newScript()->initializedGroup()) {
-                fprintf(stderr, " initializedGroup %p with %d properties",
-                        newScript()->initializedGroup(), (int) newScript()->initializedShape()->slotSpan());
+                fprintf(stderr, " initializedGroup %#" PRIxPTR " with %d properties",
+                        uintptr_t(newScript()->initializedGroup()), int(newScript()->initializedShape()->slotSpan()));
             }
         } else {
             fprintf(stderr, "\n    newScript unanalyzed");
@@ -4469,7 +4472,8 @@ TypeScript::printTypes(JSContext* cx, HandleScript script) const
         fprintf(stderr, "Eval");
     else
         fprintf(stderr, "Main");
-    fprintf(stderr, " %p %s:%" PRIuSIZE " ", script.get(), script->filename(), script->lineno());
+    fprintf(stderr, " %#" PRIxPTR " %s:%" PRIuSIZE " ",
+            uintptr_t(script.get()), script->filename(), script->lineno());
 
     if (script->functionNonDelazifying()) {
         if (JSAtom* name = script->functionNonDelazifying()->name())

js/src/vm/TypeInference.h

@@ -378,13 +378,8 @@ class TypeSet
 
     static const char* NonObjectTypeString(Type type);
 
-#ifdef DEBUG
     static const char* TypeString(Type type);
     static const char* ObjectGroupString(ObjectGroup* group);
-#else
-    static const char* TypeString(Type type) { return nullptr; }
-    static const char* ObjectGroupString(ObjectGroup* group) { return nullptr; }
-#endif
 
   protected:
     /* Flags for this type set. */