[Pkg-gmagick-im-team] Bug#770009: convert(1) very slow on mips with no FPU

[roucaries bastien]

On Sat, Aug 15, 2015 at 9:43 PM, James Cowgill <james410 at cowgill.org.uk> wrote:
> Hi,
>
> On Sat, 2015-08-15 at 14:08 +0100, Simon McVittie wrote:
>> (debian-mips: please keep me and the bug in Cc if replying.)
>>
>> On Wed, 28 Jan 2015 at 08:00:53 +0100, roucaries bastien wrote:
>> > Smell like an openmp bug.... ny memory they are a enviroment variable to
>> > disable openmp.
>>
>> I tried building with --disable-openmp on a mips porterbox
>> (minkus.debian.org, which I believe is a dual Cavium Octeon II with no FPU,
>> the same as the buildds where imagemagick has been failing).
>
> Yes, minkus and mips-aql-* all run identical hardware and do not have
> FPUs (unfortunately).
>
>> Unfortunately building with --disable-openmp doesn't seem to help.
>>
>> On Thu, 29 Jan 2015 at 19:59:45 +0100, Bastien ROUCARIES wrote:
>> > try to add to convert command line "-limit thread 1"
>>
>> Sadly that doesn't seem to help either.
>>
>> > On Fri, Jan 30, 2015 at 2:37 PM, Dejan Latinovic
>> > <Dejan.Latinovic at imgtec.com> wrote:
>> > > did anyone tried to wait some longer time to see if command will execute?
>> >
>> >   No, but the build machines wait for a pretty long time before
>> > killing (5 hours), and I've checked that it uses the proc at 200%. We
>> > can't burden the build machines like that...
>>
>> The latest experimental build (which adds some "echo", to stop sbuild
>> killing the build process after 5 hours of apparent inactivity) took
>> 19 hours. That's longer than gcc-5 took on the same hardware.
>>
>> While doing test builds yesterday evening, I was able to compile
>> imagemagick more than once, so it can't have taken longer than 2 or 3 hours;
>> assuming the porterbox and the buildd have a similar spec, that means
>> converting a SVG to a PNG 14 times is taking at least 16 hours.
>> That seems unusably slow to me. It's entirely possible that imagemagick
>> built for mips is currently only really useful on mips hardware that has
>> a FPU. Unfortunately, the mips buildds don't seem to have FPUs.
>>
>> mips porters: how common are FPUs expected to be among mips machines
>> where Debian will run?
>
> I have no numbers but I would guess that most of the machines that run
> the big endian port are network hardware which don't have FPUs.
>
>> Also, is it an ABI break for a mips library to be built with -msoft-float?
>
> Yes the ABI is different - you need a recompiled glibc (at least) to
> use -msoft-float.

Could this handled like libc-i686 ? It will be really helpful to have
a soft-float version and use ld.so to switch between.

Bastien

> Thanks,
> James