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Message-ID: <78a6ffae-7701-e0dd-3130-a9a95473d16b@deltatee.com>
Date:   Thu, 28 Apr 2022 09:44:52 -0600
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To:     Guoqing Jiang <guoqing.jiang@linux.dev>,
        linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
        Song Liu <song@kernel.org>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Stephen Bates <sbates@raithlin.com>,
        Martin Oliveira <Martin.Oliveira@eideticom.com>,
        David Sloan <David.Sloan@eideticom.com>,
        Christoph Hellwig <hch@lst.de>
References: <20220420195425.34911-1-logang@deltatee.com>
 <20220420195425.34911-2-logang@deltatee.com>
 <2a6d5554-4f71-6476-6d14-031da52005f5@linux.dev>
 <fe7f6d8a-8c66-3e90-1c52-140fe9d4cf1a@deltatee.com>
 <19d88098-7e52-38de-ceb7-a68debfbbd10@linux.dev>
From:   Logan Gunthorpe <logang@deltatee.com>
In-Reply-To: <19d88098-7e52-38de-ceb7-a68debfbbd10@linux.dev>
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Subject: Re: [PATCH v2 01/12] md/raid5: Factor out ahead_of_reshape() function
Precedence: bulk


On 2022-04-27 19:49, Guoqing Jiang wrote:
> 
> 
> On 4/28/22 12:07 AM, Logan Gunthorpe wrote:
>>
>> On 2022-04-26 19:28, Guoqing Jiang wrote:
>>>>    +static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
>>>> +                 sector_t reshape_sector)
>>>> +{
>>>> +    if (mddev->reshape_backwards)
>>>> +        return sector < reshape_sector;
>>>> +    else
>>>> +        return sector >= reshape_sector;
>>>> +}
>>> I think it can be an inline function.
>> Marking static functions in C files as inline is not recommended. GCC
>> will inline it, if it is appropriate.
>>
>> https://yarchive.net/comp/linux/inline.html
>> https://www.kernel.org/doc/local/inline.html
> 
> Thanks for the link, then I suppose those can be deleted

> linux> grep "static inline" drivers/md/md.h -r

It's standard practice to annotate small functions in headers with
"static inline". Without the inline annotation, any C file that includes
the header and doesn't use the function will emit a "defined but not
used warning".

Functions in headers also should, by definition, be small and
specifically inline-able (ie they are used as a type-safe macro).

static functions in C files (not headers) should not have the inline
keyword as GCC can optimize them and inline them as it sees fit and the
inline keyword doesn't actually do anything.

Logan