High Performance Parallel Computing: Difference between revisions

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* ''lock-free'' - guaranteed system-wide progress
* ''lock-free'' - guaranteed system-wide progress
* ''wait-free'' - guaranteed per-thread progress
* ''wait-free'' - guaranteed per-thread progress
==Measures of parallel algorithms==
* Cost: proccount * exectime
* Overhead: Cost(P) - Cost(1)
* Speedup: exectime(1) / exectime(p)
* Efficiency: Speedup / p
* Scalable if
** Efficiency is O(1) as p approaches infinity (*not* 0)
** Work(p) is linear in p
** Fixed work per processor is O(1) as p approaches infinity (*not* 0)
* Isoefficiency: How fast must our working set grow to maintain constant efficiency as processors are added?


==Papers==
==Papers==
* [http://www.cs.utexas.edu/users/dburger/teaching/cs395t-s08/papers/5_hill.pdf Amdahl's Law in the Multicore Era] by MD Hill
* [http://www.cs.utexas.edu/users/dburger/teaching/cs395t-s08/papers/5_hill.pdf Amdahl's Law in the Multicore Era] by MD Hill