Re: [RFC][PATCH] kernel: Replace timeconst.pl with a bc script

Sam Ravnborg
2013-02-15T12:01:42Z

On Thu, Feb 14, 2013 at 03:13:55PM -0800, H. Peter Anvin wrote:
> From: "H. Peter Anvin" <hpa@zytor.com>
>
> bc is the standard tool for multi-precision arithmetic. We switched
> to Perl because akpm reported a hard-to-reproduce build hang, which
> was very odd because affected and unaffected machines were all running
> the same version of GNU bc.
>
> Unfortunately switching to Perl required a really ugly "canning"
> mechanism to support Perl < 5.8 installations lacking the Math::BigInt
> module.
>
> It was recently pointed out to me that some very old versions of GNU
> make had problems with pipes in subshells, which was indeed the
> construct used in the Makefile rules in that version of the patch;
> Perl didn't need it so switching to Perl fixed the problem for
> unrelated reasons. With the problem (hopefully) root-caused, we can
> switch back to bc and do the arbitrary-precision arithmetic naturally.
>
> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Marek <mmarek@suse.cz>
> Cc: Sam Ravnborg <sam@ravnborg.org>

The kbuild stuff looks fine. The bc stuff I do not know about.

Acked-by: Sam Ravnborg <sam@ravnborg.org>