Bug#697041: atlas: FTBFS: tune/sysinfo/GetSysSum.c:47: GetL1CacheSize: Assertion `system(ln) == 0' failed

[Thorsten Glaser]

S�bastien Villemot dixit:

>In order to fix this, we need to pre-compute so-called "architectural
>defaults" for m68k. These are pre-computed timings that will speed up
>dramatically the build of the package.
>
>The procedure for doing this is explained in the README.source of atlas
>[1] (I am interested in the generated .tar.bz2).

| The ATLAS build system, before creating the binaries, first performs a very
| long series of timing tests in order to tune the library to the precise CPU on
| which it is built.

I think this is conceptionally broken, especially when an architecture
has a very broad range (think of i386 as prime example: it’s perfectly
valid to build atlas on an i80486DX CPU and use it on a multi-core
multi-GHz system, or the other way round).

Please tell me how the differences between the CPUs will affect the
generated package, i.e. whether these precomputed timings should be
done on one of the slower machines. On m68k, we have machines from
about 25 MHz (I think) up to 66/80 MHz, and “virtual machine” buildds
with roughly 60-200 MHz (I only have access to the latter).

>Either you do it yourself on a m68k machine and send me the result, or
>you give me access to such a machine (I can't login to crest.debian.net,
>it seems down).

Right, that information is old. At the moment, there’s no porterbox;
we ask people to install one of those VMs themselves or hand things
off to us with instructions.

>http://anonscm.debian.org/gitweb/?p=debian-science/packages/atlas.git;a=blob_plain;f=debian/README.source;hb=HEAD

I think these instructions are good, and can do that, yes, but
please let me know about how the speed of the CPU used for the
pregenerated timings will affect the package when run on much
slower CPUs.

Nevertheless, thanks a lot for caring about this!

Thanks,
//mirabilos
-- 
<hecker> cool ein Ada Lovelace Google-Doodle. aber zum 197. Geburtstag? Hätten
die nicht noch 3 Jahre warten können? <mirabilos> bis dahin gibts google nicht
mehr <hecker> ja, könnte man meinen. wahrscheinlich ist der angekündigte welt-
untergang aus dem maya-kalender die globale abschaltung von google ☺ und darum
müssen die die doodles vorher noch raushauen