dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Mar 03, 2011 at 04:12:37PM -0800, Johan Hake wrote:
> On Thursday March 3 2011 15:37:11 Anders Logg wrote:
> > On Thu, Mar 03, 2011 at 03:02:10PM -0800, Johan Hake wrote:
> > > Hello!
> > >
> > > I have some large forms, including some 40 exterior facet integrals. I am
> > > starting to get annoyed by a constant recompilation of these forms. I
> > > have made pretty clear that each one does not contain any numbers that
> > > changes from simulation to simulation (Using Constant or Expression for
> > > changing coefficients). But at arbitrary times, reompilations are
> > > triggered and with many integrals per form this take times ~5-20min
> > > each... The generated code is not large, no complex forms, just many
> > > integrals. I also use MixedSpaces with Real, see other email, with some
> > > 10 Real spaces.
> > >
> > > I have tried to eliminate any possible triggers for recompilations within
> > > my own code, change all dicts to ordered dicts and so on. Becuase the
> > > forms are so big it is almost impossible to debug any signature string
> > > from the form. They are hundreds of konsole lines long...
> >
> > Does the hash sum change?
>
> I suspect that, because otherwise it would not trigger a recompile.

Could you check? Try storing the values returned by __hash__ and
signature in JITObject in FFC to a file, and print some messages like
"not in cache, need to generated code", "found in cache" etc, together
with some numbers:

1. sfdirwe2349sf9wr98sdf9wer987wer97wer98we7wer9wef: not in cache
2. f09fs09wr09s8fd09s8df09we09sd8s0d9f8s0df98sdf98s: found in cache
3. ...

Then do the same thing with the full signatures in a separate
file. Then locate the form that triggers recompilation, confirm that
the hash is changed, and then compare the full signatures.

--
Anders


> But the hash sum is dependent on the repr of the form. I suspect that there
> might be some randomness built into this.
>
> Eventhough a simple case:
>
>   a = u*v*dx
>   a += u*v*ds(1)
>   a += u*v*ds(2)
>
> should create the same form each time, (This particular simple example
> probably does), I have much more complicated forms building up which I suspect
> don't create the same repr all the time. I haven't been able to debug it
> further as the repr of the forms are hundreds of konsole line...
>
> Johan
>