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Date:   Wed, 6 Jul 2022 09:35:48 -0400
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Subject: Re: [PATCH 06/13] locking/qspinlock: merge qspinlock_paravirt.h into
 qspinlock.c
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To:     Peter Zijlstra <peterz@infradead.org>,
        Nicholas Piggin <npiggin@gmail.com>
Cc:     Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
        Boqun Feng <boqun.feng@gmail.com>, linux-kernel@vger.kernel.org
References: <20220704143820.3071004-1-npiggin@gmail.com>
 <20220704143820.3071004-7-npiggin@gmail.com>
 <YsRy5HHdHhRz9z/9@worktop.programming.kicks-ass.net>
From:   Waiman Long <longman@redhat.com>
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On 7/5/22 13:20, Peter Zijlstra wrote:
> On Tue, Jul 05, 2022 at 12:38:13AM +1000, Nicholas Piggin wrote:
>> There isn't much reason to keep these separate.
> The reason was so that other paravirt implementations could be added.
>
> The CNA thing was also implemented this way...

Do you have any plan to take CNA [1] some time in the future?

Anyway, the main reason the paravirt code is separated into a separated 
file is to leave only the core part in qspinlock.c so that new users are 
overwhelmed with the messy details for the paravirt code. Putting 
everything into a single can make it harder to read for the newbies.

Also eliminating the preprocessor trick will make it harder to integrate 
a different qspinlock variant, like CNA, into the code base.

Cheers,
Longman

[1] 
https://lore.kernel.org/lkml/20210514200743.3026725-1-alex.kogan@oracle.com/