Message-ID: <49455ED2.1010909@suse.de>
Date: Mon, 15 Dec 2008 03:30:26 +0800
From: Coly Li <coly.li@suse.de>
Reply-To: coly.li@suse.de
Organization: SuSE Labs
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To: Greg KH <greg@kroah.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] avoid unnecessary assignment in lookup_bdev()
References: <49455170.6080307@suse.de> <20081214191233.GB31396@kroah.com>
In-Reply-To: <20081214191233.GB31396@kroah.com>
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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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