Week 3

Lecture Notes

Ben-Ari Ch's 1 and 2
- Ben-Ari slides: PDF
- Formula(number of possible interleavings):
  - # interleavings = (nk)! / (k!)^n
  - where n = # processes and k = # steps / process
  - assumes all n processes have same number of steps (k)

Homework

Written HW: Ben-Ari p. 39:
- Exercises 2, 3, and 4
- Due: Wed, Sep 16
- submit via Moodle

Programming Assignment 2

UPC Exercises 1.1 through 1.7
Due: Wed, Sep 23
Here's a link: private

Hints

For timing your C/UPC programs, add the following to your code

      #include <time.h>
 
      int main()
      {
        clock_t startTime = clock();
        // your code to compute the C->F temperature conversions here
        // .
        // .
        clock_t endTime = clock();
        double cpuTime = ((double) (endTime - startTime)) / CLOCKS_PER_SEC;
        // print cpu time used
        // .
        // .
      }

Here's another reference:
http://www.gnu.org/software/libc/manual/html_node/CPU-Time.html

UPC

Unified Parallel C
see resources in sidebar
tutorial introduction (see recorded zoom lecture from Monday)

ssh keys

if you haven't already done so, you need to set up your accounts for ssh'ing between workstations without password prompts
follow these steps to establish a trust connection for your account among our workstations
1. $ ssh-keygen
  hit enter through all the prompts
2. $ cd ~/.ssh
3. then type this command:
```
$ cat id_rsa.pub >> authorized_keys
```
for more information about ssh and public key authentication, see: Secure_Shell

workstations in Asprey Lab: al101 – al124
ssh into other workstations to test your ssh keys
- first time you ssh to workstation you will be prompted to confirm it's okay: yes
- subsequent logins to that workstation should be without passwords or prompts!
- this is what you need to do before attempting to run your UPC programs

setup

create a bin directory if you don't already have one:
- $ cd
- $ mkdir bin
copy my setup script into your bin directory:
- $ cp ~mlsmith/bin/set-upc-env ~/bin
run your setup script:
- $ source ~/bin/set-upc-env

copy the tutorial programs to your account under your course directory:
- $ cd ~/cs377
- $ cp -r ~mlsmith/cs377-examples/upc ./
  this will create a upc directory under your course directory
now you're ready to compile and run! (see sidebar technical reference)