[mythtv] [mythtv-commits] Ticket #11012: mythtv-0.25.2_p20120716 - configure sets incorrect CFLAGS

Raymond Wagner raymond at wagnerrp.com
Thu Aug 16 21:47:07 UTC 2012

On 8/16/2012 15:39, MythTV wrote:
> #11012: mythtv-0.25.2_p20120716 - configure sets incorrect CFLAGS
> ----------------------------------+-----------------------------
>   Reporter:  klamp <klampiar@…>    |          Owner:
>       Type:  Bug Report - General  |         Status:  closed
>   Priority:  minor                 |      Milestone:  unknown
> Component:  MythTV - General      |        Version:  Unspecified
>   Severity:  medium                |     Resolution:  Won't Fix
>   Keywords:  CFLAGS                |  Ticket locked:  0
> ----------------------------------+-----------------------------
> Comment (by klamp <klampiar@…>):
>   Hm, that's exactly something I would expect from developers of software
>   that segfaults every 60 minutues or so. No hard feelings involved, just
>   observation of performance of your code @ gentoo.

I've been a big proponent of Gentoo, and the whole concept of "compile 
your own Linux", since I started using it in the mid-2000s. I had 
previously used, and still use, FreeBSD for anything that doesn't 
require Linux for hardware compatibility, and the architecture of Gentoo 
is the next closest thing. You don't have to worry about complex chains 
of interdependent package versions. You don't have to compile in every 
feature under the sun, under the odd chance someone somewhere will want 
to use it. If you are missing a feature, recompile. If you have a 
version mismatch, recompile. If you have a compatibility issue, 
recompile. It's the simple, if perhaps not very quick, end all solution 
to most problems.

The problem with compiling everything, and potentially doing it 
repeatedly, is that the people most likely to put up with all that CPU 
load are the "tuners" who think by fiddling with every last compiler 
feature, they can eek another couple percent of performance out of their 
applications. At least in my opinion, this type of use is a perversion 
of the Gentoo ethos. Let the package system or build scripts decide what 
is the best configuration on their own. If you think you are intelligent 
enough to know better for your particular scenario, then you're 
intelligent enough to patch the ebuild or build scripts yourself. If you 
think it has value outside your own personal use, by all means submit 
the patch upstream.

When you start blanketing non-standard compile flags to everything on 
your system on a whim, that's when you really start running into 
stability issues. Most things that are not standard are not standard for 
good reason. I can honestly say I don't find MythTV the least bit 
unstable. Just about the only time I've seen a segfault since maybe 0.20 
or 0.21 has been either when I've been tinkering with some piece of code 
and am in the process of debugging it, or have done something absurd 
like pushed video to a remote XMing X11 server using XShm. If you are 
experiencing them frequently and repeatedly, open up the core dump and 
submit a ticket with the backtrace. If it were something one of the devs 
was experiencing, it would have been fixed in short order. Process of 
elimination means it's not, and so the only way it is going to be known 
is if you report it.

The one exemption to the above is when trying to perform 
cross-compilation for another system. In such cases, it is simply not 
possible for the build scripts to determine the best configuration for 
the system on their own. They need external specifications to do so for 
them, however cross-compilation is a very different problem, and must be 
handled differently than simple manual tuning parameters.

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