How FREEBSD deals with request for continuous physical pages
Linux use buddy allocator.but I find it seems that FREEBSD uses single page linked list. but SLAB and some drivers need continuous physical pages, so I wonder how FREEBSD solved this problem. Best Regards, Bao Zhao __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Re[2]: relation between PQ_CACHESIZE and PQ_L2_SIZE
--- 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]
relation between PQ_CACHESIZE and PQ_L2_SIZE
hi, all in vm_page.h PQ_CACHESIZE / PQ_L2_SIZE is always equal to 4. some think 4 represents a 4-way set associative, but I think 4 is the page size.Which is right? If I'm right, how bsd deal with 8KB page size? 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]
relation between PQ_CACHESIZE and PQ_L2_SIZE
hi,all in vm_page.h PQ_CACHESIZE/PQ_L2_SIZE is always equal to 4. what does 4 mean? some think it is 4-way set associative,but I think it is the page's size-4KB. If I'm right, How BSD deals with 8KB page size? 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]
Re: relation between PQ_CACHESIZE and PQ_L2_SIZE
--- Bruce M Simpson [EMAIL PROTECTED] wrote: On Sat, Mar 26, 2005 at 09:44:36AM -0800, Bao Zhao wrote: some think it is 4-way set associative,but I think it is the page's size-4KB. If I'm right, How BSD deals with 8KB page size? Please search this list's archives as there's a thread on this from a few years back (I was one of the protagonists). BMS Yes, I have searched the archives before I asked the question.see below: 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? Best Regard Bao Zhao __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
