From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Andres Salomon <dilinger@queued.net>,
Milton Miller <miltonm@bga.com>,
Grant Likely <grant.likely@secretlab.ca>,
devicetree-discuss@lists.ozlabs.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v2)
Date: Mon, 15 Nov 2010 09:43:15 -0800 [thread overview]
Message-ID: <4CE17133.2050101@zytor.com> (raw)
In-Reply-To: <20101115070254.GA25243@elte.hu>
On 11/14/2010 11:02 PM, Ingo Molnar wrote:
>
> * H. Peter Anvin <hpa@zytor.com> 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.
next prev parent reply other threads:[~2010-11-15 17:43 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-12 5:45 [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v2) Andres Salomon
2010-11-12 7:48 ` Milton Miller
2010-11-12 8:27 ` Andres Salomon
2010-11-14 9:50 ` Ingo Molnar
2010-11-15 4:21 ` H. Peter Anvin
2010-11-15 7:02 ` Ingo Molnar
2010-11-15 17:43 ` H. Peter Anvin [this message]
2010-11-17 6:12 ` [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v3) Andres Salomon
2010-11-29 23:39 ` [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v4) Andres Salomon
2010-12-16 2:58 ` [tip:x86/olpc] x86, olpc: Speed up device tree creation during boot tip-bot for Andres Salomon
2010-11-18 8:34 ` [PATCH 3/3] x86: OLPC: speed up device tree creation during boot (v2) Ingo Molnar
2010-11-18 11:02 ` Michael Ellerman
2010-11-18 15:04 ` H. Peter Anvin
2010-11-18 17:41 ` Andres Salomon
2010-11-18 17:48 ` H. Peter Anvin
2010-11-19 20:24 ` Andres Salomon
2010-12-23 11:57 ` Ingo Molnar
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