From 3a50c708b9bb14c2d9a55c190a4416110f672650 Mon Sep 17 00:00:00 2001
From: Ulan Degenbaev <ulan@chromium.org>
Date: Tue, 28 Apr 2020 10:29:53 +0200
Subject: [PATCH] [heap] Do not schedule follow-up GCs on memory pressure
 signal

Upon receiving a memory pressure signal V8 performs one GC and also
schedules three follow-up GCs. This may be problematic for performance
if the memory pressure signals are generated periodically.

This patch makes V8's memory pressure handler more lightweight by doing
only one GC.

Bug: chromium:1072746
Change-Id: I242534bd2c27a68188bb5e3a6b4092118c1b486c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2169930
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67422}
---
 src/heap/heap.cc | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 3779674581..b9f8a4e47e 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -3773,12 +3773,6 @@ void Heap::CheckMemoryPressure() {
                               GarbageCollectionReason::kMemoryPressure);
     }
   }
-  if (memory_reducer_) {
-    MemoryReducer::Event event;
-    event.type = MemoryReducer::kPossibleGarbage;
-    event.time_ms = MonotonicallyIncreasingTimeInMs();
-    memory_reducer_->NotifyPossibleGarbage(event);
-  }
 }
 
 void Heap::CollectGarbageOnMemoryPressure() {