Re: [PATCH] avoid unnecessary assignment in lookup_bdev()

From: Coly Li
Date: Sun Dec 14 2008 - 14:23:56 EST




Greg KH Wrote:
> On Mon, Dec 15, 2008 at 02:33:20AM +0800, Coly Li wrote:
>> In normal cases, lookup_bdev() should return successfully, therefore it's not a good idea to always
>> assign error values before checking truth/false conditions. This patch modifies code to only assign
>> error value in necessary false conditions.
>>
>> If I missed something, please correct me.
>
> I don't understand, is there some way that the current code could
> incorrectly return an error value?
>
> Is your change somehow faster? I don't think this is on any fast-path
> code, right?
For 1 or 2 lines to set error value before checking condition, that's a clean coding style. But for
more places in one function to set error value this way, I can't say that's perfect.

lookup_bdev() is just in my code review stack, the way to set error value just makes me
uncomfortable. Maybe it is because my threshold (>=3) is lower than others. This patch can not bring
up any *real* faster, but sending it out makes me feel better at least :)

--
Coly Li
SuSE PRC Labs
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