Messages in this thread |  | | | From | avik@talmai ... | | Subject | RE: [PATCH] Binding processes to selected CPUs | | Date | Wed, 13 Oct 1999 11:28:07 +0200 |
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>From: Matti Aarnio [mailto:matti.aarnio@sonera.fi] >... >> I redid my tests, this time against physical memory, >> and they show that there is no performance gain with >> 128kB caches. Perhaps machines with more cpus and >> larger caches will benefit, but the smaller ones will >> not. > > People here seem to presume that all the world SMPs are >UMA systems. > > Taxonomy of parallel computers (by David Black, back then at CMU): > - UMA Uniform Memory Access (your usual tightly coupled SMP) > - NUMA Non-Uniform Memory Access (processors have good access > to memory which is local to them, but slower access to > memory at other CPU/MEM boards; beasts like SUN E 10000) > - NORMA NO Remote Memory Access (your average Beowulf) > Spice this with Cache Coherence, and you get CC-NUMA (and CC-UMA). > > (That was after "In Search of Clusters" by Gregory F. Pfister) > > Your observations may well hold at UMA systems. > > Binding facilities make a *lot* sense at NUMA systems. > (Also memory allocation policies must be tuned >accordingly; allocing > process local memory from remote board hurts process, AND system > performance when processor most go thru system memory crossbar to > access that memory causing contention for that resource..) >
All true, but I lack the facilities to measure the performance of my patch on a NUMA :(
Does linux support a NUMA machine?
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