From: Geert Uytterhoeven <geert@linux-m68k.org>
To: George Spelvin <lkml@sdf.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Andrey Abramov <st5pub@yandex.ru>,
Andrew Morton <akpm@linux-foundation.org>,
Daniel Wagner <daniel.wagner@siemens.com>,
Dave Chinner <dchinner@redhat.com>,
Don Mullis <don.mullis@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: Re: [PATCH 1/5] lib/sort: Make swap functions more generic
Date: Fri, 15 Mar 2019 09:27:06 +0100 [thread overview]
Message-ID: <CAMuHMdVB+OgR9-rc+pksAc05vx5jeCwFF+LvBOnvmXO=VQKq2Q@mail.gmail.com> (raw)
In-Reply-To: <201903150335.x2F3ZUgS024157@sdf.org>
Hi George,
On Fri, Mar 15, 2019 at 4:36 AM George Spelvin <lkml@sdf.org> wrote:
> >> swap_bytes / swap_4byte_words / swap_8byte_words
> >> swap_bytes / swap_ints / swap_longs
> >> swap_1 / swap_4 / swap_8
> >> Pistols at dawn?
>
> On Thu, 14 Mar 2019 at 22:59:55 +0300, Andrey Abramov wrote:
> > Yes, in my opinion, swap_bytes / swap_ints / swap_longs are the
> > most readable because we have both swap_ints and swap_longs functions
> > (in one file near each other), so I don't think that there will be
> > any confusion about size.
>
> Yes, that's what I thought. They're three related but different
> functions, suffixed _bytes, _ints, and _longs. What could the
> difference possibly be? And if anyone has any lingering doubts,
> the functions are right there, with exquisitely clear comments.
>
> No to mention where they're used. Is "is_aligned(base, size, 8)"
> remotely obscure? Especially in context:
>
> if (is_aligned(base, size, 8))
> swap_func = swap_longs;
> else if (is_aligned(base, size, 4))
> swap_func = swap_ints;
> else
> swap_func = swap_bytes;
>
> What subtle and mysterious code.
>
> > But actually, it doesn't matter which name will you take, because
> > the meaning of each, in my opinion, is obvious enough, so I don't
> > mind about any of these options.
>
> I'm just amazed that this piece of bikeshedding is the most
> contentious thing about the patch series.
>
> I mean, if I'd named them:
> llanfairpwllgwyngyll()
> shravanabelagola()
> zheleznodorozhny()
> or
> peckish()
> esuriant()
> hungry()
> then yes, those would be bad names.
>
> I prefer the shorter _ints and _longs names, but this is just
> not a hill I want to die on.
Argument of least surprise: don't call something a duck if it's not
guaranteed to behave like a duck.
If I read "long", this triggers a warning flag in my head: be careful, this is
32-bit on 32-bit platforms, and 64-bit on 64-bit platforms.
There's a reason the newer I/O ioread{8,16,32} accessors use explicit
sizes, unlike the ancient x86-centric read[bwl]().
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2019-03-15 8:27 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-09 2:17 [PATCH 0/5] lib/sort & lib/list_sort: faster and smaller George Spelvin
2019-02-21 6:30 ` [PATCH 1/5] lib/sort: Make swap functions more generic George Spelvin
[not found] ` <20190309140653.GO9224@smile.fi.intel.com>
2019-03-09 15:53 ` lkml
2019-03-09 20:19 ` Andrey Abramov
2019-03-14 9:29 ` Andy Shevchenko
2019-03-14 10:09 ` George Spelvin
2019-03-14 10:41 ` Geert Uytterhoeven
2019-03-14 11:53 ` George Spelvin
2019-03-14 12:18 ` Andy Shevchenko
2019-03-14 19:59 ` Andrey Abramov
2019-03-15 3:35 ` George Spelvin
2019-03-15 8:27 ` Geert Uytterhoeven [this message]
2019-03-14 10:11 ` George Spelvin
2019-03-09 21:02 ` George Spelvin
2019-03-13 21:23 ` Rasmus Villemoes
2019-03-13 22:02 ` Geert Uytterhoeven
2019-03-13 23:15 ` George Spelvin
2019-02-21 8:21 ` [PATCH 2/5] lib/sort: Use more efficient bottom-up heapsort variant George Spelvin
2019-03-13 22:29 ` Rasmus Villemoes
2019-03-14 0:03 ` George Spelvin
2019-03-14 0:15 ` Rasmus Villemoes
2019-02-21 8:21 ` [PATCH 3/5] lib/sort: Avoid indirect calls to built-in swap George Spelvin
2019-03-05 3:06 ` [PATCH 4/5] lib/list_sort: Simplify and remove MAX_LIST_LENGTH_BITS George Spelvin
2019-03-10 21:54 ` Rasmus Villemoes
2019-03-10 22:29 ` George Spelvin
2019-03-14 9:10 ` Andy Shevchenko
2019-03-14 9:41 ` George Spelvin
2019-03-15 4:33 ` George Spelvin
2019-03-15 8:20 ` Geert Uytterhoeven
2019-03-15 10:23 ` George Spelvin
2019-03-15 12:57 ` Geert Uytterhoeven
2019-03-15 16:59 ` George Spelvin
2019-03-15 17:47 ` Geert Uytterhoeven
2019-03-15 18:53 ` Andrey Abramov
2019-03-15 19:06 ` Andy Shevchenko
2019-03-15 19:23 ` Andrey Abramov
2019-03-15 19:56 ` Andy Shevchenko
2019-03-16 3:49 ` George Spelvin
2019-03-05 5:58 ` [PATCH 5/5] lib/list_sort: Optimize number of calls to comparison function George Spelvin
2019-03-13 23:28 ` Rasmus Villemoes
2019-03-14 1:58 ` George Spelvin
2019-06-21 23:12 ` Rasmus Villemoes
2019-12-08 8:01 ` George Spelvin
2019-03-15 19:54 ` [PATCH 0/5] lib/sort & lib/list_sort: faster and smaller Andrey Abramov
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