How obtain "times" informations

Joel Sherrill joel.sherrill at OARcorp.com
Thu Feb 10 17:08:49 UTC 2000


"John M. Mills" wrote:
> 
> Silverio -
> 
> On Thu, 10 Feb 2000, Silverio Diquigiovanni wrote:
> 
> > In each bsp of libbsp exist a file called "times" in which are
> > archivied the performance of SO with that CPU/BSP.
> 
> > How are obtained ?
> > I want to calculate they for my BSPs in SH1 and SH2.
> 
> I don't remember where this was discussed, but I got them roughly as
> follows:
> 
>  1) edit the file: 'rtems/c/src/lib/libbsp/<CPU>/<BSP>/include/coverhd.h',
>     setting all the times in that file to zero;
>  2) rebuild RTEMS, ensuring that the test suite is built, but don't
>     necessarily install the new build;
>  3) run '<BLD_DIR>/<BSP>/tests/tmoverhd.exe' and capture the output;
>  4) put the values produced in the test's output back into 'coverhd.h',
>     along with notes as to the configuration you ran; and
>  5) rebuild RTEMS and this time you may install it.
> 
> Hope that works, or that someone will correct me if I mis-remembered.

That's basically it.  I would recommend a step before (3) -- run
tmck.exe.
That times various loop sizes.  The idea is that a loop of 100,000
should 
take longer than a loop of 1000.  Unless cache effect,etc get in the
way,
the time should be approximately 1000 times larger.

coverhd.h attempts to eliminate the overhead of preparing for the
service
call and returning.  THe intention is to try to time only operations
inside
the service.  On many bsps, coverhd.h is all 0.

>  - John
> 
>   John Mills, Sr. Software Engineer
>   TGA Technologies, Inc.
>   100 Pinnacle Way, Suite 140
>   Norcross, GA 30071-3633
>   e-mail: jmills at tga.com
>   Phone: 770-441-2100 ext.124 (voice)
>          770-449-7740 (FAX)
> >
> > Thank you very much !
> > Silverio
> >

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
   Support Available             (256) 722-9985



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