Re: [boost] [Fibers] Performance

Subject: Re: [boost] [Fibers] Performance
From: Giovanni Piero Deretta (gpderetta_at_[hidden])
Date: 2014-01-16 11:56:57

On Thu, Jan 16, 2014 at 4:44 PM, Hartmut Kaiser <hartmut.kaiser_at_[hidden]>wrote:

> > > > Now, if we were talking about hundreds of thousands of threads or
> > > > milions of threads, it would be interesting to see numbers for both
> > > > threads and fibers...
> > >
> > > FWIW, the use cases I'm seeing (and trust me those are very
> > > commonplace at least in scientific computing) involve not just
> > > hundreds or thousands of threads, but hundreds of millions of threads
> > > (billions of threads a couple of years from now).
> > >
> > >
> > On a single machine? That would be impressive!
>
> Well, it depends on the size of the machine, doesn't it? The no. 1 machine
> on the top 500 list [1] (Tianhe-2 [2]) has 3120000 cores (in 16,000 compute
> nodes).
>
>
Oh, right!

Do they usually present a single OS image to the application? I.e. do all
the cores share a single memory address space or nodes communicate via
message passing (MPI I presume)? std::thread-like scaling is relevant for
the first case, less so for the later.

-- gpd