[Numpy-discussion] custom atlas

Neal Becker ndbecker2 at gmail.com
Tue Jul 5 13:39:35 EDT 2011


Charles R Harris wrote:

> On Tue, Jul 5, 2011 at 8:37 AM, Charles R Harris
> <charlesr.harris at gmail.com>wrote:
> 
>>
>>
>> On Tue, Jul 5, 2011 at 8:13 AM, Neal Becker <ndbecker2 at gmail.com> wrote:
>>
>>> Charles R Harris wrote:
>>>
>>> > On Tue, Jul 5, 2011 at 7:45 AM, Neal Becker <ndbecker2 at gmail.com>
>>> wrote:
>>> >
>>> >> I thought I'd try to speed up numpy on my fedora system by rebuilding
>>> the
>>> >> atlas
>>> >> package so it would be tuned for my machine.  But when I do:
>>> >>
>>> >> rpmbuild -ba -D 'enable_native_atlas 1' atlas.spec
>>> >>
>>> >> it fails with:
>>> >>
>>> >> res/zgemvN_5000_100 : VARIATION EXCEEDS TOLERENCE, RERUN WITH HIGHER
>>> REPS.
>>> >>
>>> >> A bit of googling has not revealed a solution.  Any hints?
>>> >>
>>> >>
>>> >>
>>> > I've never seen that, OTOH, I haven't built ATLAS in the last few years.
>>> Do
>>> > you have all the power saving/frequency changing options turned off?
>>> What
>>> > version of ATLAS are you using? What CPU?
>>> >
>>> > Chuck
>>>
>>> Ah, hadn't tried turing off cpuspeed.  Try again... nope same error.
>>>
>>> 2 cpus, each:
>>> model name      : Intel(R) Core(TM)2 Duo CPU     T7500  @ 2.20GHz
>>> stepping        : 11
>>> cpu MHz         : 800.000  << that's what it says @idle
>>>
>>
>> You haven't got cpu frequency scaling under control. Linux? Depending on
>> the distro you can write to a file in /sys (for each cpu) or run a program
>> to make the setting, or click on a panel applet. Sometimes the scaling is
>> set in the bios also. Google is your friend here. I have
>>
>> $charris at f13 ~$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
>> ondemand
>>
>> And what you want to see is performance instead of ondemand.
>>
>>
> Here's some good info <http://tinyurl.com/o8o7b>.
> 
> Chuck

Thanks!  Good info.  But same result.

# service cpuspeed stop
# echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

build stopped exactly same as before.




More information about the NumPy-Discussion mailing list