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Increasing available FIFO space to prevent messaging queue deadlocks in a DMA environment

Patent ·
OSTI ID:1037748
Embodiments of the invention may be used to manage message queues in a parallel computing environment to prevent message queue deadlock. A direct memory access controller of a compute node may determine when a messaging queue is full. In response, the DMA may generate an interrupt. An interrupt handler may stop the DMA and swap all descriptors from the full messaging queue into a larger queue (or enlarge the original queue). The interrupt handler then restarts the DMA. Alternatively, the interrupt handler stops the DMA, allocates a memory block to hold queue data, and then moves descriptors from the full messaging queue into the allocated memory block. The interrupt handler then restarts the DMA. During a normal messaging advance cycle, a messaging manager attempts to inject the descriptors in the memory block into other messaging queues until the descriptors have all been processed.
Research Organization:
International Business Machines Corporation (Armonk, NY)
Sponsoring Organization:
USDOE
Assignee:
International Business Machines Corporation (Armonk, NY)
Patent Number(s):
8,112,559
Application Number:
12/241,634
OSTI ID:
1037748
Country of Publication:
United States
Language:
English

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