I'm sorry but the previous mail was sent by mistake incomplete so heres my
message:
Dear List,
I have this very weird behavior going on, I'm just implementing this
simple Matrix-Vector Multiplication program
and I'm measuring the time consumed by my program, so heres my parallel code
with asyncs :
*
val n:int=1000;
val a= new Array[Int]([0..n,0..n],((i,j):Point)=>j); //Matrix a 2
dim
val b= new Array[Int]([0..n],((i):Point)=>i); //Vector b 1
dim
val result = new Array[Int]([0..n],((i):Point)=>0); //Vector
result 1 dim result= ab
val h = new Hello();
val begin:Long = Timer.nanoTime();
finish
{
for((i,j):Point in a.region)
{
async
{
val value:int;
finish
value= h.computeMult(a,b,i,j); //this is just a
method that calculates the multiplication of each matrix row element with
the
//
corresponding vector column element
atomic result(i)+=value; // atomic sum
up of the corresponding result element
}
}
}
val end:Long = Timer.nanoTime();*
So as you can see the size of the matrix and the vector is 1000, the
execution time with "async, finish, atomic" (works in one place but
multi-activities) is *11.872344* sec where as if it worked sequentially (by
removing all "async", "finish", "atomic") it gives a better result which is
*2.39275* secs, and ofcourse as I increase the size of the dimensions it
goes worse. I'm working on a dual core machine.
How is this possible? please advise.
On Mon, Jul 5, 2010 at 5:15 AM, mohammed elsaeedy <
mohammed.elsae...@kaust.edu.sa> wrote:
> Dear List,
>
>
> I have this very weird behavior going on, I'm just implementing this
> simple Matrix-Vector Multiplication program
> and I'm measuring the time consumed by my program, so heres my parallel
> code with asyncs :
> *
> val n:int=1000;
> // 2
> val a= new Array[Int]([0..n,0..n],((i,j):Point)=>j);
> val b= new Array[Int]([0..n],((i):Point)=>i);
> val result = new Array[Int]([0..n],((i):Point)=>0);
>
> val h = new Hello();
> val begin:Long = Timer.nanoTime();
>
> finish
> {
> for((i,j):Point in a.region)
> {
> async
> {
> val value:int;
> finish
> value= h.computeMult(a,b,i,j); //this is just
> a method that calculates
> atomic result(i)+=value;
> }
> }
> }
>
> val end:Long = Timer.nanoTime();*
>
> --
> Thank you for your concern.
> Regards,
> Mohammed El Sayed
>
--
Thank you for your concern.
Regards,
Mohammed El Sayed
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