[Cython] Speedup hudson job with ccache

[Stefan Behnel]

Stefan Behnel, 07.07.2011 09:29:
> Vitja Makarov, 07.07.2011 08:54:
>> 2011/7/7 Stefan Behnel
>>
>>> Vitja Makarov, 07.07.2011 08:32:
>>>
>>>> 2011/7/7 Stefan Behnel
>>>>
>>>> Robert Bradshaw, 06.07.2011 21:32:
>>>>>
>>>>> We should get ccache on sage.math to start using it on hudson.
>>>>>
>>>>>>
>>>>>>
>>>>> It's just a single binary when installed. I have a copy in my
>>>>> ~/ccache/bin.
>>>>> Changing the Jenkins jobs now.
>>>>>
>>>>>
>>>>> Is that already used?
>>>>
>>>
>>> Actually, no. I noticed that it would a) require changes to all test jobs,
>>> and b) prevent us from getting clean test runs. I prefer a safe and clean
>>> run over a fast one.
>>>
>>>
>> a) you can set CYTHON_RUNTESTS_CCACHE globaly somewhere inside ~/.profile
>
> ;) I actually set it globally in Jenkins. However, that doesn't
> automatically remove the "rm -fr *" in the job configs - I initially
> thought that would be a problem, but, apparently, it isn't.
>
>
>>> Also, the test runner clears the target directory on startup. I wonder
>>> where you got your numbers from...
>>>
>> By default ccache stores object files inside ~/.ccache directory
>
> Hmm, I guess changing that directory into a job local directory would still
> require changing each job... Are there any concurrency issues with ccache?
>
> Anyway, I can't see a .ccache in my home directory, but if that's how it
> works, it should at least be properly enabled now.

Clearly makes a difference.

https://sage.math.washington.edu:8091/hudson/job/cython-devel-tests-py27-c/buildTimeTrend

The .ccache directory is also there now, size is ~750M. I'll move it to the 
local scratch disc, CCACHE_DIR should do that. Does it make sense to delete 
it once a week, or should that be done more often?

Stefan