unstable test testPlanSerialSuite.TestPrepareCacheDeferredFunction

[zhouqiang-cl]

Bug Report

[2021-06-22T17:49:12.217Z] FAIL: prepare_test.go:170: testPlanSerialSuite.TestPrepareCacheDeferredFunction

[2021-06-22T17:49:12.217Z] 

[2021-06-22T17:49:12.217Z] prepare_test.go:225:

[2021-06-22T17:49:12.217Z]     ...

[2021-06-22T17:49:12.217Z] /home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/util/testleak/leaktest.go:168:

[2021-06-22T17:49:12.217Z]     c.Errorf("Test %s check-count %d appears to have leaked: %v", c.TestName(), cnt, g)

[2021-06-22T17:49:12.217Z] ... Error: Test testPlanSerialSuite.TestPrepareCacheDeferredFunction check-count 50 appears to have leaked: github.com/pingcap/tidb/ddl.(*worker).start(0xc2eee055e0, 0xc2eec93980)

[2021-06-22T17:49:12.217Z] 	/home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/ddl/ddl_worker.go:157 +0x315

[2021-06-22T17:49:12.217Z] created by github.com/pingcap/tidb/ddl.(*ddl).Start

[2021-06-22T17:49:12.217Z] 	/home/jenkins/agent/workspace/tidb-unit-test-nightly/go/src/github.com/pingcap/tidb/ddl/ddl.go:364 +0x6a5

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

in ci https://ci.pingcap.net/blue/organizations/jenkins/tidb-unit-test-nightly/detail/tidb-unit-test-nightly/1761/pipeline

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master 6d032c5

[zimulala]

PTAL @dbjoa

[qw4990]

This case didn't appear for a few months, and after investigating this issue is probably caused by some other test, so I decide to close it now.
If this issue appears again, please contact me.

[ti-srebot]

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