goleak: goroutine in state sync.Cond.Wait, 5 minutes, with sync.runtime_notifyListWait on top of the stack

[YangKeao]

A goroutine leak is found in test: https://do.pingcap.net/jenkins/blue/organizations/jenkins/pingcap%2Ftidb%2Fghpr_check2/detail/ghpr_check2/15046/pipeline

goleak: Errors on successful test run: found unexpected goroutines:

[Goroutine 454293 in state sync.Cond.Wait, 5 minutes, with sync.runtime_notifyListWait on top of the stack:

goroutine 454293 [sync.Cond.Wait, 5 minutes]:

sync.runtime_notifyListWait(0xc0105b5210, 0x0)

	GOROOT/src/runtime/sema.go:527 +0x14c

sync.(*Cond).Wait(0xc002341f70?)

	GOROOT/src/sync/cond.go:70 +0x8c

google.golang.org/grpc/internal/transport.(*http2Client).keepalive(0xc00c758b40)

	external/org_golang_google_grpc/internal/transport/http2_client.go:1693 +0x245

created by google.golang.org/grpc/internal/transport.newHTTP2Client

	external/org_golang_google_grpc/internal/transport/http2_client.go:386 +0x1dcc

]

[jackysp]

It should also affect v6.5.

[tiancaiamao]

This seems to be a grpc leak and the recent leak I known is this one #48870
I'm not sure they are related.

Can't reproduce and from the above information provided, I have no idea how to debug this issue.
So close it.