Timing in mpi program, Computer Networking

Assignment Help:

MPI_Wtime ( ) returns elapsed wall-clock time in seconds as some arbitrary point in past. Elapsed time for program segment is specified by the difference between MPI_Wtime values at starting and end of process. Process clocks are not essentially synchronised, so clock values are not essentially comparable across the processes, and care must be taken in determining overall running time for parallel program. Even if clocks are explicitly synchronised, variation across clocks still can't be predictable to be significantly less than round-trip time for zero-length message among the processes.

Now, we shall explain use of these functions with an example.

Example 1:

#include

int main(int argc, char **argv) {

int i, tmp, sum, s, r, N, x[100];

MPI_Init(&argc, &argv);

MPI_Comm_size(MPI_COMM_WORLD, &s);

MPI_Comm_rank(MPI_COMM_WORLD, &r);

If(r==0)

{

printf( "Enter N:");

scanf ("%d", &N);

for (i=1; i

MPI_Send(&N, 1, MPI_INT,i, i, MPI_COMM_WORLD);

for (i=r, i

sum+= x[i];

for (i=r, i

{

PRAM Algorithms

 MPI_Recv(&tmp, 1, MPI_INT,i, i,  MPI_COMM_WORLD, &status); Sum+=tmp;

}

printf( "%d", sum);

}

else {

MPI_Recv(&N, 1, MPI_INT,0, i, MPI_COMM_WORLD, &status);

for (i=r, i

sum+= x[i];

MPI_Send(&sum, 1, MPI_INT, 0, i, MPI_COMM_WORLD);

}

MPI_Finalize( );

}


Related Discussions:- Timing in mpi program

What is bandwidth, Question 1 What is bandwidth?                         >...

Question 1 What is bandwidth?                         >>What is the bandwidth of                            a) Telephone signal                            b) Commercial radio broa

What do you mean by osi, What do you mean by OSI? The Open System Inter...

What do you mean by OSI? The Open System Interconnection (OSI) reference model explains how information from a software application in one computer moves by a network medium to

Building a defense in networking, Q. Building a Defense in networking? ...

Q. Building a Defense in networking? When building a defense you must use a layered approach that includes securing - The network infrastructure the communications protocol

Circuit switched and packet-switched mode for sending a file, Two hosts are...

Two hosts are connected by a path made of four links as shown in the figure below. The links are of data rate R = 2 Mbps each. Host A has a file of size F = 1,000,000 bytes to tran

How to protect computer hardware by threats, How to protect computer Hardwa...

How to protect computer Hardware by threats The first component in the computer system vulnerable to attacks or threats, and most important to be protected, is the hardware.

Multicast extension to ospf, MOSPF MOSPF is multicast extension to OSP...

MOSPF MOSPF is multicast extension to OSPF. This protocol is extension of OSPF which is a unicast routing protocol which make MOSPF a combination of unicast and multicast prot

Define character stuffing, Define Character Stuffing? In byte stuffing ...

Define Character Stuffing? In byte stuffing (or character stuffing), a particular byte is added to the data section of the frame when there is a character with the same pattern

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd