[RC5] ogr percentage done - WHY impossible?

Dipsy dipsy100 at lineone.net
Wed Mar 21 14:45:04 EST 2001



> -----Original Message-----
> From: owner-rc5 at lists.distributed.net
> [mailto:owner-rc5 at lists.distributed.net]On Behalf Of Dan Oetting
> Sent: 19 March 2001 22:56
> To: rc5 at lists.distributed.net; Stephen Garrison
> Subject: Re: [RC5] ogr percentage done - WHY impossible?
>
>
> on 3/19/01 2:20 PM, Stephen Garrison wrote:
>
> >On Thu, 15 Mar 2001, Dan Oetting wrote:
> >
> >> The total number of 6-stubs that are valid for OGR-24 is
> somewhere around
> >> 50 million if I remember correctly. The difficulty of
> verifying each stub
> >> will depend on how early the various tests cut off the recursion
> >> branches. The biggest factor for stub difficulty will be the length of
> >> the stub. Shorter stubs have less constraints and will take longer to
> >> process. The longest stubs will hit most of the cutoffs very
> soon so will
> >> take almost no time to process.
> >
> >Even if it isn't exact to say the percentage of work done is equal to the
> >number of stubs done (a) it is our best guess and (b) it should "average
> >out" of the life of the contest to be a pretty decent guess of the amount
> >of work completed and amount left to be completed.
> >
> >P.S. You had another msg later on about how "you shouldn't have trusted
> >your memory" concerning the number of stubs. The number in the msg I am
> >responding to corresponds to OGR-24. The other one that you
> "corrected" it
> >with was for OGR-25.
>
> My memory was off on both counts. The only number I have is for for
> OGR-25. I wouldn't trust anything d.net has to say until they stop
> covering up the problems.
>
> The distributed.net OGR code was derived from GARSP. The last ruler GARSP
> ran was OGR-23 and that is all the code was good for. None of the
> original developers of GARSP came along to help port the code so the
> OGR-23 limits were never fixed for the d.net runs of OGR-24 and OGR-25.
>
> The first problem to surface was an internal table was being accessed one
> byte passed the end. This was first reported almost a year ago but was
> soon dismissed when recompiling with different options allowed the client
> to pass the internal tests. [All the clients running today are accessing
> this invalid byte but they all pass the tests because the "valid" results
> were also generated by the buggy code] Someone finally discovered the
> fault was not a compiler error and at some point I was brought in because
> I actually knew something of how the OGR code worked. It was still weeks
> before this was even discussed on the coders list. I was waiting to let
> d.net make the official announcement and I finally forced their hand by
> posting a reference to the bug. I think this all transpired back in
> Nov/Dec but don't trust my memory.
>
> I was able to prove that even though this was a major bug the client
> results were still valid. The bug was causing the client to work about
> 15% extra but no valid rulers were being skipped.
>
> But then other bugs started being discussed on the coders list. The
> thread safety problem was brought up where the buffer between the main
> client and the core thread could get corrupted. A serious problem but if
> it doesn't happen too often the invalid results can be filtered out in
> the verification pass. Stubs were being truncated in checkpoints. This
> only affected a few clients and cause some rulers to be retested when
> restarting from the checkpoint. And then the reason we don't know how
> many stubs there are is because the master stub generator was throwing
> out all stubs with a total length greater than 70. This was valid for 3
> mark stubs in OGR-23 but is totally wrong for 6 mark stubs in OGR-24.
>
> I don't know what's holding up the new clients. The OGR code has been
> fixed, the buffer problems could be patched with a simple handshaking,
> the master stub generator needs to be rebuilt but it is essentially the
> same code as in the OGR core. And somebody needs to explain to the users
> why a year or two of crunching is going to be thrown out when OGR-24 and
> OGR-25 are restarted.
>
> I've tried to let the word out softly but my posts are being censored by
> the d.net staff. You should switch your clients to RC5 until the new
> clients are released so you don't waist more cycles. Or go hunt aliens
> with Seti at home like I have been doing.
>
> -- Dan Oetting
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>


Wow, at least somebody has woken up. I switched to RC5 ages ago.....

Scott

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