Re: [julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Tim Holy
Just noticed that you're allocating memory on each iteration. If you have the patience to write out all those matrix operations explicitly, it should help. Alternatively, perhaps try ParallelAccelerator. Best, --Tim On Monday, August 29, 2016 10:49:40 AM CDT Marius Millea wrote: > Thanks, just

[julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Ralph Smith
Dict can be slow. Try d_cl = Array{Array,1} for i=1:np d_cl[i] = copy(inv_cl) end I can't say if that leads to good threads since nthreads() gives me only 1 today.

Re: [julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Marius Millea
Thanks, I did notice that, but regardless this shouldn't affect the scaling with NCPUs, and in fact as you say, it doesn't change performance at all. On Monday, August 29, 2016 at 7:27:44 PM UTC+2, Diego Javier Zea wrote: > > Looks like the type of *d_cl* isn't inferred correctly. *d_cl =

Re: [julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Marius Millea
Thanks, just tried wrapping the for loop inside a function and it seems to make the @threads version slightly slower and serial version slightly faster, so I'm even further from the speedup I was hoping for! Reading through that Issue and linked ones, I guess I may not be the only one seeing

Re: [julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Diego Javier Zea
Looks like the type of *d_cl* isn't inferred correctly. *d_cl = Dict(i => ones(3,3,nl) for i=1:np)::Dict{Int64,Array{Float64,3}}* helps with that, but I din't see a change in performance. Best

Re: [julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Tim Holy
Very quickly (train to catch!): try this https://github.com/JuliaLang/julia/ issues/17395#issuecomment-241911387 and see if it helps. --Tim On Monday, August 29, 2016 9:22:09 AM CDT Marius Millea wrote: > I've parallelized some code with @threads, but instead of a factor NCPUs > speed

[julia-users] @threads not providing as big speedup as expected

2016-08-29 Thread Marius Millea
I've parallelized some code with @threads, but instead of a factor NCPUs speed improvement (for me, 8), I'm seeing rather a bit under a factor 2. I suppose the answer may be that my bottleneck isn't computation, rather memory access. But during running the code, I see my CPU usage go to 100%