Fande Kong <[email protected]> writes: > On Fri, Jun 1, 2018 at 9:49 PM, Jed Brown <[email protected]> wrote: > >> Fande Kong <[email protected]> writes: >> >> > On Fri, Jun 1, 2018 at 5:40 PM, Matthew Knepley <[email protected]> >> wrote: >> > >> >> On Fri, Jun 1, 2018 at 7:09 PM, Smith, Barry F. <[email protected]> >> >> wrote: >> >> >> >>> >> >>> Fande, >> >>> >> >>> This is a great question. I am forwarding it to Mike Heroux who >> >>> has a high level position in the ECP; because I have similar concerns >> and >> >>> also don't have a good answer. ParMetis does indeed have a poor >> license and >> >>> essentially no support. Perhaps Mike has some ideas. >> >>> >> >> >> >> Also, the parallel scalability is crappy (sorry George). >> >> >> > >> > Do we know the underneath reason why the parallels scalability is poor? >> > Poor algorithm? Poor implementation? >> >> My recollection is that the k-way refiner has an O(k^2) data structure. > > > Theoretically speaking, does the data structure have to be O(k^2)? Any > existing algorithm to avoid that?
Theoretically no, but it isn't clear what data structure would be fast. > >> > Here is a list of partitioning packages >> > https://en.wikipedia.org/wiki/Graph_partition#cite_note-patoh-16 >> > >> > Anybody has experiences on any of the listed packages? >> >> Many of them are unmaintained. KaHIP is the most interesting in my >> opinion. > > > Why KaHIP is the most interesting? The algorithm is novel or better than > ParMetis or PTScotch? The published results are promising. We know ParMETIS scales poorly and PTScotch is relatively slow. > >> It is GPLv2 which is an issue for some users, though I recall >> the lead developer might consider a more permissive license. I chatted >> with John Peterson about this a few months ago, but I don't know if he >> installed and tested it. I suspect there would be interest if you could >> contribute toward --download-kahip and a MatPartitioning implementation. >> > > I definitely will take a try. > > > Fande, > > >> >> > Fande, >> > >> > >> >> Bill Gropp has proposed in the past developing a new >> >> partitioner along more scalable lines, such as the Teng algorithm used >> in >> >> Padma's 2013 SC paper >> >> (https://dl.acm.org/citation.cfm?id=2503280). Jed favors a multilevel >> >> approach which I do not understand. >> >> Its a shame that all the development time that went into PT-Scotch could >> >> not produce a scalable, open >> >> partitioner. Also, the label-push stuff seems only to work well for >> highly >> >> connected graphs, not meshes. >> >> >> >> Matt >> >> >> >> >> >>> >> >>> Barry >> >>> >> >>> >> >>> >> >>> >> >>> On Jun 1, 2018, at 5:46 PM, Kong, Fande <[email protected]> wrote: >> >>> >> >>> Hi Developers, >> >>> >> >>> I have introduced MatPartitioning interface to MOOSE. It is working >> >>> great, and we can use all external partitioning packages via a simple >> >>> interface. >> >>> >> >>> But here is a concern. Almost all the packages are not under >> development >> >>> any more. Does this make a bug fix more difficult in the future. Also >> some >> >>> of them have bad licenses. >> >>> >> >>> I was wondering there is any other partitioning package in the >> community? >> >>> >> >>> Thanks, >> >>> >> >>> Fande, >> >>> >> >>> >> >>> >> >> >> >> >> >> -- >> >> What most experimenters take for granted before they begin their >> >> experiments is infinitely more interesting than any results to which >> their >> >> experiments lead. >> >> -- Norbert Wiener >> >> >> >> https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/> >> >> >>
