From 806edfa6eaef99c3071c09e362c386ef241f7fd3 Mon Sep 17 00:00:00 2001
From: Omer Katz <omerkatz@chromium.org>
Date: Tue, 31 Jan 2023 23:36:38 +0100
Subject: [PATCH] [heap] Release invalidates slots set in MinorMC.

Bug: v8:12612, chromium:1411746
Change-Id: I6c06e6c924f9f548cb2014172d467ed19a5abbc5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4208940
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#85605}
---
 src/heap/mark-compact.cc | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index ba043ceae9..b01cb0c238 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -4173,10 +4173,6 @@ void VerifyRememberedSetsAfterEvacuation(Heap* heap,
 
     // GCs need to filter invalidated slots.
     DCHECK_NULL(chunk->invalidated_slots<OLD_TO_OLD>());
-    // TODO(v8:12612): This DCHECK holds for MinorMC because MinorMC doesn't use
-    // incremental/concurrent marking, and thus it is not possible to allocate
-    // an invalidated slots set during MinorMC. This will likely break once
-    // MinorMC marks concurrently.
     DCHECK_NULL(chunk->invalidated_slots<OLD_TO_NEW>());
     if (collector == GarbageCollector::MARK_COMPACTOR) {
       DCHECK_NULL(chunk->invalidated_slots<OLD_TO_SHARED>());
@@ -6149,6 +6145,9 @@ void PageMarkingItem::MarkUntypedPointers(YoungGenerationMarkingTask* task) {
         return CheckAndMarkObject(task, slot);
       },
       SlotSet::FREE_EMPTY_BUCKETS);
+  // The invalidated slots are not needed after old-to-new slots were
+  // processed.
+  chunk_->ReleaseInvalidatedSlots<OLD_TO_NEW>();
 }
 
 void PageMarkingItem::MarkTypedPointers(YoungGenerationMarkingTask* task) {