ptest.jl

ptest.jl

const A = randn(1000, 1000);
const numx = 10_000;
const v = randn(1000, numx);

addprocs(4)

@sync begin
    let A2=A, v2=v, numx2=numx
        for p in workers()
            @spawnat p global const A = A2;
            @spawnat p global const numx = numx2;
            @spawnat p global const v = v2;
        end
    end
end


@everywhere begin
  do_stuff(r::UnitRange) = ([do_stuff(mm) for mm in r]; nothing)
  function do_stuff(mm::Int64)
    sum( A * v[:, mm] )
  end
end

@time do_stuff(1:numx);

chunks = Base.splitrange(numx, nworkers())

for c in chunks
 @time do_stuff(c);
end

@time @sync begin
  for c in chunks # @parallel does the same
    @spawn @time do_stuff(c)
  end
end

@time @sync begin
  for c in chunks
    wait(@spawn @time do_stuff(c))
  end
end