Re: [PATCH V11 3/5] printk: hash addresses printed with %p

From: Geert Uytterhoeven
Date: Wed Dec 06 2017 - 03:48:21 EST


Hi Linus,

On Wed, Dec 6, 2017 at 12:33 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Dec 5, 2017 at 2:57 PM, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>> Lowest 3 is good enough for all natural types, up to long long.
>> We may still receive complaints from people who care about seeing if
>> a pointer is cacheline-aligned or not. Fixing that may need up to 7 bits, I'm
>> afraid, which is a bit too much to give up.
>
> I really think even the lowest three is a bit too much.
>
> Who really cares? If it's something that is particularly _about_
> alignment (ie an alignment trap), maybe just print out those bits
> separately.

If I'm not mistaken, some architectures don't generate alignment traps, but
just zero the LSBs.

> And for everything else? It's purely about getting used to it.

Yes, we will get used to it.

I agree that for debugging during development, we will just use %px and be
fine.

Storm in a glass of water, everybody will have forgotten by the time v4.16 is
released.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

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