# DidaWiki

### Strumenti Sito

magistraleinformaticanetworking:spm:spm1314phi

# Xeon PHI HOWTO (for SPM1314 course)

## Access

The machine with the Xeon PHI cards may be accessed using the IP address

131.114.137.225

and the credentials distributed during the lessons to the attending students.

The credentials give access to a local account onto a Sandy Bridge multicore hosting the 2 PHI PCIe boards.

In order to access the PHI, users should use an

ssh mic0

or

ssh mic1

command from the Sandy Bridge machine shell prompt.

## Set up environment

Before using the Intel tools you should setup the shell enviornment in such a way you can find all the right tools. You should use a

source /opt/intel/composer_xe_2013.1.117/bin/compilervars.sh intel64

command to this purpose. It is a good practice to append the command at the end of your home .bashrc file.

## Compiling

In order to produce executable programs for the PHI

1. the icc compiler must be used to compile the source code on the Sandy Bridge host, and
2. the -mmic flag should be specified

As an example, to compile the prog.cpp source code for the PHI we should use a command such as

icc -mmic prog.cpp -o prog

## Running

To run a program on the Xeon PHI:

• copy the program exceutable to the PHI home
scp prog mic0:

(You can use either mic0 or mic1 on this machine)

• login to the PHI OS:
ssh mic0

(You should use the same micXX you used to copy)

• run the code:
./prog

and you'll see the results (cout writes) on the terminal

• go back to the compiler shell
exit

## Running from remote

To run a program on the PHI without leaving the Sandy Bridge shell, consider using a couple of commands:

• first copy the program executable with a
scp progname micX:
• then run it from the current shell with a
ssh micX progname

You can consider writing a small shell/perl script to automatize the process.

magistraleinformaticanetworking/spm/spm1314phi.txt · Ultima modifica: 17/12/2013 alle 13:57 (6 anni fa) da Marco Danelutto