On Wed, Jun 14, 2006 at 03:21:55PM -0500, Jim C. Nasby wrote: > One idea would be to keep something akin to a FIFO, where the backend > would write records instead of updating/over-writing them, and the > reader process would only read records where there was no risk that they > were still being written. That would mean that the reader would need to > stay at least one record behind the backend, but that's probably > manageable.
The problem with a FIFO is that the pointers controlling where the start/end are become the contention. The only thing I can think of is to have the backends only write atomic types and give each backend their own cache-line. The profiler would simply wake up every N ms and read each value, accumulating them somewhere. No locking and there would be a maximum of one cache-line bounce per backend per N ms. I'm not sure you can get better than that under the situation. Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to > litigate.
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