linux-kernel - Re: [RFC PATCH v3 04/15] rcu: Add a small-width RCU watching counter debug option

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Message-ID: <xhsmh1pz5j2zx.mognet@vschneid-thinkpadt14sgen2i.remote.csb>
Date: Wed, 20 Nov 2024 17:15:14 +0100
From: Valentin Schneider <vschneid@...hat.com>
To: Peter Zijlstra <peterz@...radead.org>
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Subject: Re: [RFC PATCH v3 04/15] rcu: Add a small-width RCU watching
 counter debug option

On 20/11/24 15:50, Peter Zijlstra wrote:
> On Tue, Nov 19, 2024 at 04:34:51PM +0100, Valentin Schneider wrote:
>> A later commit will reduce the size of the RCU watching counter to free up
>> some bits for another purpose. Paul suggested adding a config option to
>> test the extreme case where the counter is reduced to its minimum usable
>> width for rcutorture to poke at, so do that.
>> 
>> Make it only configurable under RCU_EXPERT. While at it, add a comment to
>> explain the layout of context_tracking->state.
>
> Note that this means it will get selected by allyesconfig and the like,
> is that desired?
>

I would say no

> If no, depends on !COMPILE_TEST can help here.

Noted, thank you!