From 669c90463c976b90501bebc1ccdea659fb5d3cbf Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Thu, 27 May 2021 21:23:35 +0800
Subject: [PATCH] sorter: reduce memory malloc to avoid too much CPU overhead
 (#1854) (#1863)

---
 cdc/puller/sorter/heap_sorter.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/cdc/puller/sorter/heap_sorter.go b/cdc/puller/sorter/heap_sorter.go
index a82c1cde67d..7cf99afc138 100644
--- a/cdc/puller/sorter/heap_sorter.go
+++ b/cdc/puller/sorter/heap_sorter.go
@@ -33,6 +33,7 @@ import (
 
 const (
 	flushRateLimitPerSecond = 10
+	sortHeapCapacity        = 32
 )
 
 type flushTask struct {
@@ -86,7 +87,7 @@ func newHeapSorter(id int, out chan *flushTask) *heapSorter {
 		id:        id,
 		inputCh:   make(chan *model.PolymorphicEvent, 1024*1024),
 		outputCh:  out,
-		heap:      make(sortHeap, 0, 65536),
+		heap:      make(sortHeap, 0, sortHeapCapacity),
 		canceller: new(asyncCanceller),
 	}
 }
@@ -159,7 +160,7 @@ func (h *heapSorter) flush(ctx context.Context, maxResolvedTs uint64) error {
 			return nil
 		}
 		oldHeap = h.heap
-		h.heap = make(sortHeap, 0, 65536)
+		h.heap = make(sortHeap, 0, sortHeapCapacity)
 	} else {
 		task.dealloc = func() error {
 			task.markDeallocated()