On Wednesday 20 February 2008 23:52, Balbir Singh wrote: > Andi Kleen wrote: > > Document huge memory/cache overhead of memory controller in Kconfig > > > > I was a little surprised that 2.6.25-rc* increased struct page for the > > memory controller. At least on many x86-64 machines it will not fit into > > a single cache line now anymore and also costs considerable amounts of > > RAM. > > The size of struct page earlier was 56 bytes on x86_64 and with 64 bytes it > won't fit into the cacheline anymore? Please also look at > http://lwn.net/Articles/234974/
BTW. We'll probably want to increase the width of some counters in struct page at some point for 64-bit, so then it really will go over with the memory controller! Actually, an external data structure is a pretty good idea. We could probably do it easily with a radix tree (pfn->memory controller). And that might be a better option for distros. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
