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From: Nicholas N. <nj...@ca...> - 2003-05-07 21:02:50
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On Wed, 7 May 2003, Josef Weidendorfer wrote: > > Is a round-robin mapping of threads to processors accurate, ie. > > representative of what would really happen? > > I think the regular case is e.g. to run a multithreaded application with 4 > threads on a 4-processor machine, and round robin mapping is accurate in a "n > threads/n processor" szenario. How common is that scenario? > The typical use case is here to check if there's e.g. cache trashing > (independed data regularily accessed by the two processors are located in the > same cache line, leading to a lot of cache invalidation/misses) or general > performance slowdown because shared data is accessed often. So with the cache trashing, Cachegrind/Calltree with this feature wouldn't necessarily be reporting a figure that's representative of any real-life configuration, but would give a general indication of how well different threads interact, yes? That sounds like it could be useful. N |