On Wed, Jul 11, 2012 at 03:48:28PM -0500, Seth Jennings wrote: > On 07/11/2012 02:42 PM, Konrad Rzeszutek Wilk wrote: > >>>> Which architecture was this under? It sounds x86-ish? Is this on > >>>> Westmere and more modern machines? What about Core2 architecture? > >>>> > >>>> Oh how did it work on AMD Phenom boxes? > >>> > >>> I don't have a Phenom box but I have an Athlon X2 I can try out. > >>> I'll get this information next Monday. > >> > >> Actually, I'm running some production stuff on that box, so > >> I rather not put testing stuff on it. Is there any > >> particular reason that you wanted this information? Do you > >> have a reason to believe that mapping will be faster than > >> copy for AMD procs? > > > > Sorry for the late response. Working on some ugly bug that is taking > > more time than anticipated. > > My thoughts were that these findings are based on the hardware memory > > prefetcher. The Intel > > machines - especially starting with Nehelem have some pretty > > impressive prefetcher where > > even doing in a linked list 'prefetch' on the next node is not beneficial. > > > > Perhaps the way to leverage this is to use different modes depending > > on the bulk of data? > > When there is a huge amount use the old method, but for small use copy > > (as it would > > in theory stay in the cache longer). > > Not sure what you mean by "bulk" or "huge amount" but the > maximum size of mapped object is PAGE_SIZE and the typical > size more around PAGE_SIZE/2. So that is what I'm > considering. Do you think it makes a difference with copies > that small? I was thinking in terms of time. So if there are many requests coming in at some threshold, then use one method. > > Thanks, > Seth > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
