Re: Multithreaded Atlas can be used by GCC-4.3.3-sjlj-mingw-TDM (Was Re: Sjlj vs dwarf2 on mingw for octave)

[Tatsuro MATSUOKA]

Hello



> If I use dw2 version of gcc-4.3.3, griddata3.m cannot be executed due to the 
> error of pthread
> mutex.
> （I do not remember in detail.）

I found the comment on Octave thread in Japan.

assertion !pthread_mutex_lock ( &(ROOT->mutex) ) failed, line 74 of file
/home/atlas/atlas3.8.2-gcc4.3.3-2/../ATLAS3.8.2 
//src/pthreads/misc/ATL_signal_tree.c 

At that time I used ATLAS3.8.2 but the same error happens at the case of 
ATLAS3.8.3.

This is perhaps because pthread-win32 is made for gcc witb sjlj-EH but I do not 
have any evidence 
for that.

Regards

Tatsuro


 
--- Tatsuro MATSUOKA  wrote:

> Hello
> 
> I wrote prevously
> > Sjlj octave-3.0.4RC7
> > octave.exe:2> testOregoB
> > ans =  1.5469
> > 
> > Dwarfs octave-3.0.4RC5
> > octave:3> testOregoB
> > ans =  1.1875
> 
> The speed of octave interpreter that built by dw2-eH is 25-30% faster than 
> that by sjlj-EH on
> mingw-GCC-4.3.3-TDM.
> 
> However I found that the merit of sjlj EH on the view point of multithreaded 
> ATLAS. 
> 
> By gcc-4.3.3 mingw (sjlj), I found that multithreaded atlas can be used, 
> without error by
> configured
> with the following
>  
> ../../octave-3.0.4RC7/configure --prefix=/c/Programs/octave-3.0.4RC7s
> --with-blas=--with-blas='-lptf77blas -latlas -lpthread'
> 
>  d:\usr\Tatsu\mingwhome\octaves\octave-3.0.4RC7\scripts/geometry\griddata3.m  
> PASS    2/2
> 
> If I use dw2 version of gcc-4.3.3, griddata3.m cannot be executed due to the 
> error of pthread
> mutex.
> （I do not remember in detail.）
> 
> The speed check by 
> n=2000; A=randn(n); B=randn(n);tic; C=A*B; t=toc, MFLOPS=2*n^3/t*1e-6
> 
> MFLOPS =  4970.9 (Ht-Pentium-4 prescott 3.4GHz)
> 
> On the other hand single thread ATLAS by GCC-4.3.3-dw2 on the same computer, 
> n=2000; A=randn(n); B=randn(n);tic; C=A*B; t=toc, MFLOPS=2*n^3/t*1e-6
> 
> MFLOPS = 4830.2 
> 
> The multithreaded atlas is a little bit faster than the single thread atlas 
> even though 
> one physical core with hyper-threading.
> (On GotoBLAS with smp on for my computer is slower than that by single 
> thread.)
> 
> If the multi-thread atlas to Core2Duo and so on, the merit of sjlj EH may 
> exist.
> 
> Of course, the data should be accumulated for other computers.
> I will distribute the dependency library kit for mingw in thre near future on 
> my web.
> 
> Similar kind of experiments on Unix are also to be useful for users who would 
> like to carry out
> fast
> Matrix calculation of large n (n x n).
> 
> Regards
> 
> Tatsuro 
> 


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