Параллельные вычисления

Xeon Phi Performance Question

We have a current software application that we currently only run a single instance of at once.  It requires no user input, simply runs for a pre-defined amount of time essentially navigating through a flowchart and spitting out data.  However, we desire to run multiple (100+) instances of it at once.  It is a relatively complicated program, with a decent amount of branching as it decides what to do with each node as it reaches it.  There is no current memory bandwidth issues, either.  However, it is technically running the same code in parallel...

Cast a void* to COIBUFFER


I have a memory allocated on the host (void* A) and this memory is copyed in using the offload pragma (#pragma offload in (A)). and I want to have the coresponding adresse on the MIC. is there a way to have this adresse ?. Also I tired to use the  COIBufferGetSinkAddress (COIBUFFER in_Buffer, uint64_t ∗out_pAddress) how aver this function requires a COIBUFFER and not a void*. So if you think this can work, how can I casttype a void* to a COIBUFFER ?


Anyone compiled zlib for MIC ?

Hi Everyone,

I'm compiling a static library for Xeon Phi, 

and this library uses  'zlib compression' library ( http://www.zlib.net/ ) .

When I try to build zlib on my CentOS computer (which contains the Xeon Phi),

I keep getting errors during 'make test' which are shown in the .log file attached.

I've tried 2 configure command, both showed the same errors :

1) CC=icc CFLAGS="-mmic" CHOST=x86_64 ./configure

Setting number_of_user_threads for Intel® Math Kernel Library FFTW3 wrappers

Consider the case when you

  • Create a FFTW3 plan and use the plan for sequential DFT computation on each thread in your parallel region
  • Use Intel Math Kernal Library (Intel MKL) FFTW3 wrappers
  • Want the best performance

Intel MKL FFTW3 wrappers are thread safe by default. However, you should set one additional Intel MKL variable to get the best performance with Intel MKL. Set the number_of_users_threads variable as described below.

In C:

#include "fftw3.h"

  • Средний
  • Intel® C++ Composer XE
  • Библиотека Intel® Math Kernel Library
  • OpenMP*
  • FFT
  • FFTW
  • FFTW3
  • fourier transform
  • MKL FFTW3 wrappers
  • number_of_users_threads
  • Оптимизация
  • Параллельные вычисления
  • Многопоточность
  • offload step


         Everyone. I have a question on  the #pragma offload approach. I have read the paper "Offload Compiler Runtime for the Intel® Xeon Phi™ Coprocessor" from the website http://software.intel.com/en-us/articles/offload-runtime-for-the-intelr-.... There is a description of offload like this: "At appropriate times, code that is embedded in the host-side binary is extracted, moved and invoked, and memory management is begun.".

    Automatic offload not working to run Octave operations on Phi


    I'm trying to execute some Octave operations on Phi, using automatic offload feature, but i'm not being able to do coprocessor starts working.
    These are the steps I followed:

    - Install Octave 3.2.4 using Intel MKL libraries -> Folowing the article http://software.intel.com/en-us/articles/using-intel-mkl-in-gnu-octave

    - After installing Octave I've checked with "ldd /usr/local/bin/octave" that all mkl libraries are correctly linked.

    TCP communication between multiple phi cards on the same host

    I thought I was done with communication problems, but I guess not.  I just installed another three phi cards on a workstation, but I'm having the following communication problem.  I can ssh from the host to any phi card and back, but I can't ssh from one card to another, such as from mic0 to mic1.  I can't even ping one card from another card.  I assume that all cards should be able to communicate with all others on the same host. The default TCP addresses are being used ( for host, for mic0, for mic1, etc).

    Any ideas? Thanks!

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