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Date:   Tue, 27 Oct 2020 16:45:33 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Chris Wilson <chris@chris-wilson.co.uk>
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Subject: Re: [tip: locking/core] lockdep: Fix usage_traceoverflow
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On Tue, Oct 27, 2020 at 01:29:10PM +0000, Chris Wilson wrote:

> <4> [304.908891] hm#2, depth: 6 [6], 3425cfea6ff31f7f != 547d92e9ec2ab9af
> <4> [304.908897] WARNING: CPU: 0 PID: 5658 at kernel/locking/lockdep.c:3679 check_chain_key+0x1a4/0x1f0

Urgh, I don't think I've _ever_ seen that warning trigger.

The comments that go with it suggest memory corruption is the most
likely trigger of it. Is it easy to trigger?