linux-kernel - Re: [PATCH v4 05/25] reboot: Warn if restart handler has duplicated priority

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Message-ID: <7875d10b-0d9b-ca29-668b-630ea3650fd0@gmail.com>
Date:   Fri, 10 Dec 2021 22:49:47 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Michał Mirosław <mirq-linux@...e.qmqm.pl>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Russell King <linux@...linux.org.uk>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, Guo Ren <guoren@...nel.org>,
        Geert Uytterhoeven <geert@...ux-m68k.org>,
        Greg Ungerer <gerg@...ux-m68k.org>,
        Joshua Thompson <funaho@...ai.org>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Sebastian Reichel <sre@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Greentime Hu <green.hu@...il.com>,
        Vincent Chen <deanbo422@...il.com>,
        "James E.J. Bottomley" <James.Bottomley@...senpartnership.com>,
        Helge Deller <deller@....de>,
        Michael Ellerman <mpe@...erman.id.au>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
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        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Yoshinori Sato <ysato@...rs.sourceforge.jp>,
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        Dave Hansen <dave.hansen@...ux.intel.com>,
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Subject: Re: [PATCH v4 05/25] reboot: Warn if restart handler has duplicated
 priority

10.12.2021 22:44, Dmitry Osipenko пишет:
> 10.12.2021 22:42, Dmitry Osipenko пишет:
> ...
>>>> There is no strong requirement for priorities to be unique, the reboot.c
>>>> code will work properly.
>>>
>>> In which case adding the WARN() is not appropriate IMV.
>>>
>>> Also I've looked at the existing code and at least in some cases the
>>> order in which the notifiers run doesn't matter.  I'm not sure what
>>> the purpose of this patch is TBH.
>>
>> The purpose is to let developer know that driver needs to be corrected.
>>
>>>> The potential problem is on the user's side and the warning is intended
>>>> to aid the user.
>>>
>>> Unless somebody has the panic_on_warn mentioned previously set and
>>> really the user need not understand what the WARN() is about.  IOW,
>>> WARN() helps developers, not users.
>>>
>>>> We can make it a strong requirement, but only after converting and
>>>> testing all kernel drivers.
>>>
>>> Right.
>>>
>>>> I'll consider to add patches for that.
>>>
>>> But can you avoid adding more patches to this series?
>>
>> I won't add more patches since such patches can be added only after
>> completion of transition to the new API of the whole kernel.
>>
> 
> Thank you for the review.
> 

I meant you, Rafael, and Michał, just in case :)