Re: [Paracomp-devel] Crash in pcSystemFinalize

[Shree K. <shr...@hp...>]

Hi Stefan,

On Wed, 2008-05-14 at 11:14 +0000, Stefan Eilemann wrote:
> >
> > PC rev 63 seems to be faster than Eq rev 1880. Am I
> > missing something ?
> 
> No - I think it is due to the fact that Eq supports different sizes
> between the images, which makes the code a bit more complex.
> 

Can you explain what you mean by "Eq supports different sizes between
the images" ? 

Paracomp does it too. It only expects the width and height of the
compositing regions to match for all the source & destination operands.
The test program you have doesn't exercise this case.

> >
> >
> > Of course, I'm still puzzled about the perf difference between Eq and
> > rev 63 :-)
> 
> I assume you meant rev 62?!
> 

No I meant 63. I observe the following relation in terms of performance
(I've quoted the table below):

PC rev 62 < eq rev 1880 < PC rev 63

Essentially, rev 63 = rev 62 + using your compositing code from rev 1880
for your particular test case.

>> Eq, rev 1880:
>> ./Darwin/test: DB first op:  41.4328 ms (1272.77 MB/s)
>> ./Darwin/test: DB second op: 28.1947 ms (1870.36 MB/s)
>> ./Darwin/test: DB 15 images: 92.7198 ms (2843.75 MB/s)
>>
>>
>> PC, rev 63:
>> ./Darwin/test: DB first op:  39.5884 ms (1332.07 MB/s)
>> ./Darwin/test: DB second op: 26.9765 ms (1954.83 MB/s)
>> ./Darwin/test: DB 15 images: 87.6801 ms (3007.2 MB/s)
>>
>> PC, rev 62:
>>
>> ./Darwin/test: DB first op:  45.064 ms (1170.21 MB/s)
>> ./Darwin/test: DB second op: 32.2106 ms (1637.17 MB/s)
>> ./Darwin/test: DB 15 images: 111.401 ms (2366.88 MB/s)
>>
>

Cheers
-- Shree