We present the first NC algorithm for scheduling n unit length tasks on m identical processors for the case where the precedence constraint is an interval order. Our algorithm runs on a priority concurrent read, concurrent write parallel Ε½ 2 . Ε½ 5 . Ε½ 3 . random access machine in O log n with O n pr
An efficient parallel algorithm for scheduling interval ordered tasks
β Scribed by Yoojin Chung; Kunsoo Park
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- English
- Weight
- 187 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0885-064X
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β¦ Synopsis
We present an efficient parallel algorithm for scheduling n unit length tasks on m identical processors when the precedence graphs are interval orders. Our algorithm requires OΓ°log 2 v ΓΎ Γ°n log nΓ=vΓ time and OΓ°nv 2 ΓΎ n 2 Γ operations on the CREW PRAM, where v can be any number between 1 and n: By choosing v ΒΌ ffiffi ffi n p
; we obtain an OΓ° ffiffi ffi n p log nΓ-time algorithm with OΓ°n 2 Γ operations. For v ΒΌ n=log n; we have an OΓ°log 2 nΓ-time algorithm with OΓ°n 3 =log 2 nΓ operations. The previous solution takes OΓ°log 2 nΓ time with OΓ°n 3 log 2 nΓ operations on the CREW PRAM. Our improvement is mainly due to a simple dynamic programming recurrence for computing the lengths of optimal schedules and a reduction of the m-processor scheduling problem for interval orders to that of finding a maximum matching in a convex bipartite graph.
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