Re: checkpatch guide for newbies

From: Alexander Holler
Date: Tue Sep 24 2013 - 18:11:35 EST

Am 24.09.2013 22:13, schrieb Bjorn Helgaas:
On Tue, Sep 24, 2013 at 1:29 PM, Peter Senna Tschudin
<peter.senna@xxxxxxxxx> wrote:
On Tue, Sep 24, 2013 at 7:26 PM, Alexander Holler <holler@xxxxxxxxxxxxx> wrote:
On Mon, Sep 23, 2013 at 3:01 AM, Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Long Lines

Historically screens were 80 characters wide and it was annoying when
code went
over the edge. These days we have larger screens, but we keep the 80
limit because it forces us to write simpler code.

Sorry, but that just isn't true and never was. Having a line wide limit of
80 characters while forcing tabs to be 8 characters long limits most code to
just 72 characters. And even less (max 64) inside constructs like if, for or

The only outcome of that totally silly rule is that variable names will
become shorted to silly acronyms almost nobody does understand make code

In the context of a two-sentence paragraph, Dan's original text is
pithy and accurate. A Wikipedia article would deserve more

Obviously the skill of the programmer is the overwhelming factor, but
I think restricting the line length does help encourage simpler,
better-factored code. It's also part of the whole "it's better to be
consistent than to be better" thing. If 95% of the files in Linux use
80-character lines and the remainder use longer lines, it's just an
ongoing hassle for the reader.

I always feel like beeing in the IT stone age when programmers thought they
have to use variable names like a, b and c to save storage, memory or to
type less when reading linux kernel code.
I was about to disagree because I've never seen variables named a, b
or c, but I found that there are at least 2238 variables named a, b or
c in linux-next. This is not good.

That is not self-evident. In many cases, e.g., loop iterators, simple
names are fine. Nothing is gained by renaming a loop counter from "a"
to "array_index." Simple names for simple things help the reader
focus on more important aspects of the code.

Sure and I'm the last one who wants that people do have to use anything else than i for simple loop counters. And allowing longer lines doesn't mean people have to use long names, it allows them use them (if it makes sense). That's a big difference.

On the other side it's almost impossible to use verbose variable or function names where they would make sense. Not to speak about all the ugly splitted lines just to be below that ancient CGA limit.

So such a limit doesn't enforces or helps people to write simpler code. It encourages using silly names and confusing line breaks, but in no way it helps in writing more simple code. It might make help to keep the code base consistent in regard to line lengths and confusing line breaks, but that's almost all it does.


Alexander Holler
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at