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Subject: Re: More on the "bad math" after an important email...

Author: Robert Hyatt

Date: 16:51:47 09/03/02

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On September 03, 2002 at 18:24:20, Eugene Nalimov wrote:

>I believe that speedup table is what count here. And it is geniune.
>
>And there *is* way to obtain anyone's Ph.D. thesis in the USA, and Bob mentioned
>it several days ago.
>
>BTW, I don't see why majority of code in CopyToSMP() should be done under lock.
>All that should be done under lock is the assignment "c->used=1;". After that
>you should release the lock. I would not be surprised if it'll speed up the
>search with many (>= 16) CPUs.
>
>Personally, I'd replaced loops that copy data by memcpy() calls where possible.
>That's not Fortran, and compiler should generate the code that works for the
>memory-aliased case; by using memcpy() instead of loop you are telling the
>compiler that there are no aliases.
>
>And of course "used" should be declared "volatile". [Bob, do you read that]?

I will look at that.  I have blown volatiles more than once, by omitting
them.  Fortunately, on the PC it rarely hurts anything as there are not
enough registers to keep things around very long.  But I certainly had some
serious problems on the first SMP sparc I tried.  :)

thanks, btw...

I'll look tonite...


>
>Thanks,
>Eugene
>
>On September 03, 2002 at 18:03:14, Gian-Carlo Pascutto wrote:
>
>>However reasonable your explanations may be, the gist of your DTS article
>>and the most important thing for comparison were the speedup numbers. After
>>what we discovered and what you just posted, it is clear that they are
>>based on very shaky foundations.
>>
>>What's far worse, until you were directly accused, there was no indication
>>whatsoever for all the fiddling that was done with the auxiliary data. When
>>you were accused, you denied again, until other people supported Vincent's
>>point of view, when you suddenly got an email from an unknown person you're
>>not willing to disclose that 'refreshed your memory'.
>>
>>Additionally, the only other thing to support DTS, you PhD thesis, appears
>>to be basically totally unfindable for third parties.
>>
>>I hope you realize that a request from you to trust your numbers isn't
>>very convincing. In fact, with what we know now, I'm pretty sure the
>>article would never have gotten published in the first place.
>>
>>If Vincent wanted to discredit your results, then as far as I'm concerned,
>>he's succeeded 100%.
>>
>>--
>>GCP



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