[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#63986: Julia is very slow
From: |
Cayetano Santos |
Subject: |
bug#63986: Julia is very slow |
Date: |
Thu, 22 Jun 2023 15:26:30 +0200 |
User-agent: |
mu4e 1.10.3; emacs 29.0.91 |
>mer. 21 juin 2023 at 22:39, Cayetano Santos <csantosb@inventati.org> wrote:
>>mer. 21 juin 2023 at 16:36, Ludovic Courtès <ludovic.courtes@inria.fr> wrote:
>
>> Hey!
>>
>> The benchmark you posted, Cayetano, is:
>>
>> julia -e 'using Pkg; Pkg.add("BenchmarkTools"); using BenchmarkTools; N =
>> 1000; A = rand(N, N); B = rand(N, N); @btime $A*$B'
>>
>> This is a matrix multiplication that gets delegated to the underlying
>> BLAS right. Running it under ‘perf record’ confirms it:
>>
>> Samples: 139K of event 'cycles:u', Event count (approx.): 99624880590
>> Overhead Command Shared Object Symbol
>> 35.27% .julia-real libblas.so.3.9.0 [.] dgemm_
>> 3.99% .julia-real libjulia-internal.so.1.8 [.] gc_mark_loop
>> 2.60% .julia-real libjulia-internal.so.1.8 [.] apply_cl
>> 1.06% .julia-real libjulia-internal.so.1.8 [.] jl_get_binding_
>>
>> We’re using libblas.so (presumably from the ‘lapack’ package) and not
>> OpenBLAS, so no wonder it’s slow.
>>
>> Could it be that:
>>
>> "LIBBLAS=-lopenblas"
>> "LIBBLASNAME=libopenblas"
>>
>> is ineffective? I think we have a lead!
>
> Are we following all instructions here ?
>
>
> https://docs.julialang.org/en/v1.8/devdocs/build/distributing/#Notes-on-BLAS-and-LAPACK
>
> I’m thinking about the variables LIBLAPACK and LIBLAPACKNAME.
To complete my previous comment, I just realised that
Base.USE_BLAS64
gives "true" when running fast. Guix julia gives "false".
C.
- bug#63986: Julia is very slow, Cayetano Santos, 2023/06/09
- bug#63986: Julia is very slow, Ludovic Courtès, 2023/06/14
- bug#63986: Julia is very slow, Simon Tournier, 2023/06/19
- bug#63986: Julia is very slow, Ludovic Courtès, 2023/06/21
- bug#63986: Julia is very slow, Cayetano Santos, 2023/06/21
- bug#63986: Julia is very slow,
Cayetano Santos <=
- bug#63986: Julia is very slow, Efraim Flashner, 2023/06/22
- bug#63986: Julia is very slow, Simon Tournier, 2023/06/22
- bug#63986: Julia is very slow, Efraim Flashner, 2023/06/22
- bug#63986: Julia is very slow, Cayetano Santos, 2023/06/22
- bug#63986: Julia is very slow, Simon Tournier, 2023/06/22
- bug#63986: Julia is very slow, Ludovic Courtès, 2023/06/23
- bug#63986: Julia is very slow, Efraim Flashner, 2023/06/23
- bug#63986: Julia is very slow, Simon Tournier, 2023/06/23
- bug#63986: Julia is very slow, Simon Tournier, 2023/06/23
- bug#63986: Julia is very slow, Efraim Flashner, 2023/06/23