Ref https://github.com/JuliaLang/julia/pull/17429
On Friday, August 12, 2016 at 7:39:40 PM UTC+2, Doan Thanh Nam wrote: > > Hi, > > I am new to Julia Language and I am curious to use it for my work. > Recently, I have tried to use it for some of my projects and observed some > interesting cases. > > First of all, when I start Julia REPL without adding any worker processes > and do matrix multiplication. Julia takes all CPU cores in my computer to > speed up the computation. I guess it used OpenBLAS. The code is > X = randn(5000, 5000); Y = randn(5000, 5000); X * Y; > > > However, after adding some worker processes by using *addprocs*(4) and do > matrix multiplication. It runs the computation on only 1 CPU core and it > slows down my performance. Even if I remove all worker processes that I add > and run the multiplication again, it still uses one CPU core to do. The > code is > addprocs(4); X = randn(5000, 5000); Y = randn(5000, 5000); X * Y; > rmprocs(2); rmprocs(3); rmprocs(4);rmprocs(5);X = randn(5000, 5000); Y = > randn(5000, 5000); X * Y; > > > My question here is that: Are there any ways to use all cores to do matrix > multiplication ( and other matrix methods) with multiple cores after > *addprocs*()? > > Thanks. >
