I suspect we could calculate a safe number of steps past a rebuild to skip
in your turbo mode. But that's for another day. This code needs to go...
On Tue, Nov 10, 2020 at 12:56 PM David Cerutti <dscerutti.gmail.com> wrote:
> Yep. skin_permit should avoid rebuilds if the test passes the more
> permissive threshold. And I do actually seem to remember seeing that code,
> or something to the effect "don't rebuild pair list if we just created it"
> in the comments as I was working on the turbo mode. So whatever that code
> is, it is pretty ancient and may affect test cases if we purge it, even
> though that is probably a good idea.
>
> Dave
>
>
> On Tue, Nov 10, 2020 at 3:51 PM Scott Le Grand <varelse2005.gmail.com>
> wrote:
>
> > So looking at skin_permit, it looks like I can blow away this junk and
> > skin_permit will do the rest?
> >
> > On Tue, Nov 10, 2020 at 12:16 PM Scott Le Grand <varelse2005.gmail.com>
> > wrote:
> >
> > > ~line 2000 of kNeighborList.cu:
> > >
> > > extern "C" void kNLSkinTest(gpuContext gpu)
> > > {
> > > static unsigned counter = 0;
> > > static unsigned lastCounter = gpu->sim.skinnb * 14;
> > >
> > > int counterCut = lastCounter*0.2;
> > > unsigned interval = 1;
> > > if (counter++ > counterCut && (counter % interval) == 0) {
> > >
> > > etc...
> > >
> > > Not only is this uncool, it's done with local static variables which is
> > > just horrible...
> > >
> > > On Tue, Nov 10, 2020 at 12:07 PM David Cerutti <dscerutti.gmail.com>
> > > wrote:
> > >
> > >> I wasn't aware of the code doing anything like NB skin tests only
> every
> > >> other step. The "turbo" mode is enabled by setting skin_permit to a
> > value
> > >> between 0.5 and 1.0. See here:
> > >>
> > >> http://ambermd.org/GPUPerformance.php
> > >>
> > >> Where in the code is the call to the pairlist check being skipped on
> > half
> > >> the steps?
> > >>
> > >> Dave
> > >>
> > >>
> > >> On Tue, Nov 10, 2020 at 2:03 PM Scott Le Grand <varelse2005.gmail.com
> >
> > >> wrote:
> > >>
> > >> > At some point, PMEMD stopped doing NB skin tests every step and it
> now
> > >> does
> > >> > them every other step. No matter what your view on the validity of
> > doing
> > >> > so, doing this under the hood all the time without informing the
> user
> > is
> > >> > uncool to the max.
> > >> >
> > >> > I am turning this off by default. Any objections? Dave, how does one
> > >> enable
> > >> > your turbo mode? Because this seems cool there, just not on 100% of
> > the
> > >> > time with no option to turn it off.
> > >> >
> > >> > Scott
> > >> > _______________________________________________
> > >> > AMBER-Developers mailing list
> > >> > AMBER-Developers.ambermd.org
> > >> > http://lists.ambermd.org/mailman/listinfo/amber-developers
> > >> >
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> > >>
> > >
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> >
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Received on Tue Nov 10 2020 - 13:00:04 PST
