linux-kernel - Re: [PATCH 4/4] lockdep: Fix workqueue crossrelease annotation

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Date:   Fri, 1 Sep 2017 22:51:48 +0900
From:   Byungchul Park <max.byungchul.park@...il.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Byungchul Park <byungchul.park@....com>,
        Ingo Molnar <mingo@...nel.org>, Tejun Heo <tj@...nel.org>,
        Boqun Feng <boqun.feng@...il.com>, david@...morbit.com,
        Johannes Berg <johannes@...solutions.net>, oleg@...hat.com,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        kernel-team@....com
Subject: Re: [PATCH 4/4] lockdep: Fix workqueue crossrelease annotation

On Fri, Sep 1, 2017 at 9:38 PM, Peter Zijlstra <peterz@...radead.org> wrote:
> On Fri, Sep 01, 2017 at 07:16:29PM +0900, Byungchul Park wrote:
>
>> It would be gone _only_ at the time the history overrun, and then it
>> will be built again. So, you are wrong.

s/it will be built again/the acquisition will be added into the xhlock
array again/

Now, better to understand?

> How will it ever be build again? You only ever spawn the worker thread
> _ONCE_, then it runs lots and lots of works.
>
> We _could_ go fix it, but I really don't see it being worth the time and

We don't need to fix it spending time and effort. Just *revert* all your
wrong patches.

> effort, its a few isolated locks inside the kthread/workqueue code.

Please point out what I am wrong and what you want to say, *with* my
latest example. Doing it with my example would be very helpful to
understand you.

-- 
Thanks,
Byungchul