View
26
Download
0
Category
Preview:
DESCRIPTION
Introduction. Name: Jani Peusaari Office: 6608 Contact: Email: Jani.Peusaari @lut.fi Reception hours: Tuesday 13-14. Timetable. wk 1: Introduction, terms, other basic stuff wk 2: Complexity analysis wk 3: Abstract models wk 4: Abstract models, architectures - PowerPoint PPT Presentation
Citation preview
Introduction
Name: Jani Peusaari
Office: 6608
Contact:
Email: Jani.Peusaari@lut.fi
Reception hours: Tuesday 13-14
Timetable
wk 1: Introduction, terms, other basic stuffwk 2: Complexity analysiswk 3: Abstract modelswk 4: Abstract models, architectureswk 5: Interconnections, embeddingwk 6: Communicationswk 7: Practical issues, Los grande
coding assignment
Application areas
YOU TELL US
Terms
• Task – Tehtävä– General description of a processing element
• Process – Prosessi– A process runs in some arbitrary computer
• Thread – Säie– ”Lightweight process”, threads run in some
arbitrary process
• Communication– Between tasks, processes, threads
Terms
• Shared Memory – Jaettu muisti• Distributed Memory – Hajautetty muisti• Architecture
– Way to connect Processors to each other
• Problem size: n, N• Number of tasks: p, P• Memory: m, M• Time to complete certain operation: t, T
Example 1
The job is to estimate how long it takes to count n numbers with p people, One person calculates n numbers in (n-1)tc. Let us presume, that there are eight persons and the numbers are easily divided among them. Transferring the results takes tw. How long it takes for n people if:
a) They are sitting in a circle b) They are sitting in 2 by 4 rows.
Example 2
One person uses (n-1)tc to count n numbers. Is it possible that p persons solves the problem in less time than
(n-1)tc/p ?
Justify your answer !
Example 3
What if the eight people from assignment number 1 calculate partial sums on the blackboard so that everyone can see the others results as soon as they are ready.
How long a time it takes now and how about assignment number 2?
Recommended