Re: [PATCH 3/3] x86: OLPC: speed up device tree creation during boot(v2)

From: H. Peter Anvin
Date: Mon Nov 15 2010 - 12:43:58 EST


On 11/14/2010 11:02 PM, Ingo Molnar wrote:
>
> * H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>
>> What? What is wrong with static variables in functions? It really doesn't seem
>> to be a good idea to make them file-scope if they don't need to be.
>
> They are very easy to overlook and mix up with regular stack variables and i've seen
> (and introduced myself) a number of bugs due to them.
>
> They also often are used in buggy ways (with SMP not taken into consideration), so
> overlooking them during review compounds their negative effects. Putting them in
> front of the function isnt a big deal in exchange.
>
> There are people who never overlook them (like yourself), but my brain is wired up
> differently.
>

However, I have to vehemently object to putting them in a wider scope
than is otherwise necessary. I agree that static variables should be
used sparsely if at all (there really are vary few uses of them that are
valid), but putting them in a larger scope screams "I'm used in more
than one function", and that is *not* a good thing.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.

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