Hi Brad, This is very interesting. Could you tell us what you have done to identify this problem?
Thanks, Gaëtan Le 16 mars 2012 21:59, Bradley Lowekamp <[email protected]> a écrit : > After digging a little further I think this problem may better be called > "False Sharing" and there is a wikipedia page about it: > http://en.wikipedia.org/wiki/False_sharing > > Additionally the common cache block size for intel processors is 64 words. > And the caching protocols should maintain this consistently between > processors if shared. > > Brad > > On Mar 16, 2012, at 3:16 PM, Lowekamp, Bradley (NIH/NLM/LHC) [C] wrote: > > Hello, > > I have just made the StatisticsImageFilter go ~58X faster on my multi-core > platform for large data, by fixing the cache thrashing which was going on: > > http://review.source.kitware.com/#/c/4771/1 > > When adjacent memory is modified by different processors, it must maintain > consistency across the cores. This is of non-trivial expense then > considered on the per-pixel level. If anyone is looking for an example case > of bad cache thrashing I think this it about as good as you can do. > > I am just sending this e-mail to make sure everyone is on the look out for > this type of problem, and will take a note (Jira?) of where similar > enhancements can occur. > > > Thanks for keeping an eye out, > Brad > > ======================================================== > Bradley Lowekamp > Medical Science and Computing for > Office of High Performance Computing and Communications > National Library of Medicine > [email protected] > > > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Kitware offers ITK Training Courses, for more information visit: > http://kitware.com/products/protraining.php > > Please keep messages on-topic and check the ITK FAQ at: > http://www.itk.org/Wiki/ITK_FAQ > > Follow this link to subscribe/unsubscribe: > http://www.itk.org/mailman/listinfo/insight-developers > > > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Kitware offers ITK Training Courses, for more information visit: > http://kitware.com/products/protraining.php > > Please keep messages on-topic and check the ITK FAQ at: > http://www.itk.org/Wiki/ITK_FAQ > > Follow this link to subscribe/unsubscribe: > http://www.itk.org/mailman/listinfo/insight-developers > >
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