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From: <val...@ce...> - 2006-03-09 22:14:38
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[Ooops... I think the first time I responded to this the email went directly to Nick... sorry] Thanks for the info. I can now see where my cache misses are occurring most. I have a couple of more questions: Is a miss on the instruction cache as costly as on data cache? It appears that in some places I am approaching and even passing 50% miss rate on the data cache reads. This sounds pretty bad. What does "improve locality of accesses to them" mean in regards to the crucial data structure? Thanks, E Quoting Nicholas Nethercote <nj...@cs...>: > On Wed, 8 Mar 2006 val...@ce... wrote: > >> I am starting to use Valgrinds cachegrind to test my program for caches >> performance. Once i do this, how can I improve the cache performance? that >> is, how can I eliminate or reduce cache missies in my app? Are >> certain types >> of programming techniques more prone to cache misses? For example, nested >> loops? Certain data type declarations etc? Is there a good source of >> information on the internet? > > There is no easy answer. Cachegrind points you in the right > direction, but it can't tell you how directly how to fix your > program. There is lots of information about caches on the internet, > google for some. In general, try to make the crucial data structures > smaller, and improve locality of accesses to them. > > Nick > > > ------------------------------------------------------- > This SF.Net email is sponsored by xPML, a groundbreaking scripting language > that extends applications into web and mobile media. Attend the live webcast > and join the prime developer group breaking into this new coding territory! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 > _______________________________________________ > Valgrind-users mailing list > Val...@li... > https://lists.sourceforge.net/lists/listinfo/valgrind-users > |