From b1379a61b5b5c8d332c3dc6d65d2a93020568aa1 Mon Sep 17 00:00:00 2001
From: Shenghui Wu <793703860@qq.com>
Date: Mon, 9 May 2022 15:16:33 +0800
Subject: [PATCH] executor: release memory usage of task in
 indexJoin/indexHashJoin (#34418)

close pingcap/tidb#34417
---
 executor/index_lookup_hash_join.go | 4 ++++
 executor/index_lookup_join.go      | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/executor/index_lookup_hash_join.go b/executor/index_lookup_hash_join.go
index 51f21c2491e77..5287f43a59cbe 100644
--- a/executor/index_lookup_hash_join.go
+++ b/executor/index_lookup_hash_join.go
@@ -464,6 +464,10 @@ func (iw *indexHashJoinInnerWorker) run(ctx context.Context, cancelFunc context.
 	}
 	h, resultCh := fnv.New64(), iw.resultCh
 	for {
+		// The previous task has been processed, so release the occupied memory
+		if task != nil {
+			task.memTracker.Detach()
+		}
 		select {
 		case <-ctx.Done():
 			return
diff --git a/executor/index_lookup_join.go b/executor/index_lookup_join.go
index 6961a22a5c8ab..06d04746b8925 100644
--- a/executor/index_lookup_join.go
+++ b/executor/index_lookup_join.go
@@ -318,6 +318,10 @@ func (e *IndexLookUpJoin) getFinishedTask(ctx context.Context) (*lookUpJoinTask,
 		return task, nil
 	}
 
+	// The previous task has been processed, so release the occupied memory
+	if task != nil {
+		task.memTracker.Detach()
+	}
 	select {
 	case task = <-e.resultCh:
 	case <-ctx.Done():
@@ -559,7 +563,7 @@ func (iw *innerWorker) constructLookupContent(task *lookUpJoinTask) ([]*indexJoi
 				return nil, err
 			}
 			if rowIdx == 0 {
-				iw.lookup.memTracker.Consume(types.EstimatedMemUsage(dLookUpKey, numRows))
+				iw.memTracker.Consume(types.EstimatedMemUsage(dLookUpKey, numRows))
 			}
 			if dHashKey == nil {
 				// Append null to make lookUpKeys the same length as outer Result.