--- Igor Shmukler <[EMAIL PROTECTED]> wrote: > > > http://lists.freebsd.org/mailman/htdig/freebsd-hackers/2003-June/001655.html > > But what puzzled me is : why not page size is > a > > factor when calculating the number of colors? > > Page coloring in freebsd was implemented by John > Dyson. It is needed to better utilize the > cache. Depending on cache's implementation > fully-associative vs. 4-way vs 2-way etc you might > have problems. > > A subset of bits (low-bits) from the page frame's > (physical) address tells us where can data be > stored in processor cache. We want a relatively > equal distribution of these "colors" so that we > utilize as much of cache real estate as possible. > Hence, we are interested in the size of a > set, not size of a page. > > I am sure, there are whole bunch of articles written > about this. I could give you some pointers > offline. > > Igor. > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to > "[EMAIL PROTECTED]" > I have read two papers. Both of them think page size impact the number of colorings.
The first one: R.E.Kessler "page placement algorithms for large-indexed caches" excerpt from this paper , "Let N be the cache size in pages and B=N/A(A is associativity) be the number of bins" The second paper William L.Lynch "The Interaction Of Virtual Memory and Cache Memory" excerpt from this paper ,section 5.3 "The number of colors depends on the page size. As th page size increases, the number of colors decreases until the page size is equal to the cache size-per-degree-of-associative" and I find Alan Cox's post http://lists.freebsd.org/pipermail/freebsd-current/2004-June/028470.html quoted from the post "1. Cache size alone does not correctly determine the number of colors,except for direct map caches. The correct formula is (cache size in bytes / page size in bytes) / degree of cache associativity Thus, the comments would lead one to configure his/her system with too many colors. " I think Alan is right . What's you opinion? Thanks! Best Regards! Bao Zhao __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/ _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
