CS6801- Multi­core Architectures and Programming

What is OpenMP ?

• OpenMP = Open Multi-threading

• OpenMP = Open Multi-tasking

• Multi tasking

• OpenMP = Open Multi-processing

Compiling and running OpenMP code

• hellosmp

• g++ fopenmp hellosmp.c -o hellosmp

• gcc -fopenmp hellosmp.c -o hellosmp

• gcc -fopenmp hellosmp.c -o hellosmp

  ./hellosmp

Specifying the parallel region (creating threads)

• pragma omp parallel

  {}

• omp parallel

  {}

• #pragma omp parallel

  {}

• pragma omp

  {}

Display "Hello, world." using multiple threads.

• main(void)

  {

  #pragma omp parallel

  {

  printf("Hello, world.\n");

  }

  
  

  return 0;

  }

• #include < stdio.h >

  
  

  int main(void)

  {

  #pragma omp parallel

  {

  printf("Hello, world.\n");

  }

  
  

  return 0;

  }

• #include < stdio.h >

  
  

  int main(void)

  {

  pragma omp parallel

  {

  printf("Hello, world.\n");

  }

  
  

  return 0;

  }

• #include < stdio.h >

  
  

  int main(void)

  {

  #pragma

  {

  printf("Hello, world.\n");

  }

  
  

  return 0;

  }

What Is Shared-memory Architecture?

• A space is visible to all execution threads.

• A multi address space is visible to all execution threads.

• A address space is visible to all execution threads.

• A single address space is visible to all execution threads.

What Is Task-throughput?

• The number of multi tasks completed in a given time

• The number of singel tasks completed in a given time

• The number of tasks completed in a given time

• The number of thread completed in a given time

Efficiency is

• E= S

• E= S/P

• E= P

• E= P/S

State Amdahl’s law.

• 1/(1-p) + (p/s)

• (1-p) + (p/s)

• 1/(1-p)

• (1-p) + (p/s)

In message passing a process receives information by executing the

• Send

• Send Primitive

• Receive

• Receive Primitive

SCSI system organization Quiz

• small common-system interface

• small common-system interaction

• small computer-system interface

• small computer-system interaction