I've split the patch up into three parts to simplify review: The first part counts the size of things we tenure. Note, it would be awesome if we could just use rt->gcBytes, but I think we also really need to count slot/element data here to get a useful picture of our working-set-size.

This patch changes NurseryLayout/asLayout to NurseryChunkLayout/asChunk(i) and uses the chunk concept throughout the Nursery.

This patch implements the actual growing and shrinking heuristics and logic.

Comment on attachment 753402 [details] [diff] [review] 3 of 3: v0 Bill is on vacation, so switching review to Brian.

Comment on attachment 753395 [details] [diff] [review] 1 of 3: collect tenured size Review of attachment 753395 [details] [diff] [review]: ----------------------------------------------------------------- Sorry for the delay.

Comment on attachment 753401 [details] [diff] [review] 2 of 3: v0 Review of attachment 753401 [details] [diff] [review]: ----------------------------------------------------------------- ::: js/src/gc/Nursery.h @@ +103,5 @@ > + /* Pointer to the last byte of space in the current chunk. */ > + uintptr_t currentEnd_; > + > + /* The chunk that is currently being allocated from. */ > + int currentChunk_; Maybe 'The index of the chunk that is ...' @@ +106,5 @@ > + /* The chunk that is currently being allocated from. */ > + int currentChunk_; > + > + /* The index after the last chunk that we will allocate from. */ > + int endChunk_; Could this variable be numActiveChunks_ instead, for a more obvious meaning? @@ +146,2 @@ > }; > + NurseryChunkLayout &asChunk(int offset) const { The 'as' in this method name is a bit troublesome, as it suggests a downcast rather than a plain accessor. Maybe just Nursery::chunk(i) instead? Also, the |offset| variable should be |index| instead. @@ +164,5 @@ > + JS_ALWAYS_INLINE void setCurrentChunk(int chunkno) { > + JS_ASSERT(chunkno < NumNurseryChunks); > + JS_ASSERT(chunkno < endChunk_); > + currentChunk_ = chunkno; > + currentEnd_ = asChunk(chunkno).end(); It looks like this method could also update position_, which would allow removing writes to position_ in the callers.

Comment on attachment 753402 [details] [diff] [review] 3 of 3: v0 Review of attachment 753402 [details] [diff] [review]: ----------------------------------------------------------------- ::: js/src/gc/Nursery.cpp @@ +520,5 @@ > JSObject *obj = static_cast<JSObject*>(p->forwardingAddress()); > JS_TraceChildren(&trc, obj, MapAllocToTraceKind(obj->tenuredGetAllocKind())); > } > > + /* Resize the nursery to closer match our current working set size. */ grammar