unstable test TestMemTracker4InsertAndReplaceExec

[hawkingrei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

2. What did you expect to see? (Required)

3. What did you see instead (Required)

    oom_test.go:111: 

        	Error Trace:	executor/oomtest/oom_test.go:111

        	Error:      	Not equal: 

        	            	expected: "expensive_query during bootstrap phase"

        	            	actual  : ""

        	            	

        	            	Diff:

        	            	--- Expected

        	            	+++ Actual

        	            	@@ -1 +1 @@

        	            	-expensive_query during bootstrap phase

        	            	+

        	Test:       	TestMemTracker4InsertAndReplaceExec

4. What is your TiDB version? (Required)

[hawkingrei]

    oom_test.go:166: 

        	Error Trace:	executor/oomtest/oom_test.go:166

        	Error:      	Not equal: 

        	            	expected: ""

        	            	actual  : "limit executor close takes a long time"

        	            	

        	            	Diff:

        	            	--- Expected

        	            	+++ Actual

        	            	@@ -1 +1 @@

        	            	-

        	            	+limit executor close takes a long time

        	Test:       	TestMemTracker4DeleteExec

https://do.pingcap.net/jenkins/blue/organizations/jenkins/pingcap%2Ftidb%2Fghpr_unit_test/detail/ghpr_unit_test/22107/pipeline