Large pages, large blocks, and large problems
Posted Sep 19, 2007 16:51 UTC (Wed) by avik
In reply to: Large pages, large blocks, and large problems
Parent article: Large pages, large blocks, and large problems
It's an oversimplification. Suppose you have a large memory machine and
you're doing completely random access. With 4KB pages, you'll get a tlb
miss and two cache hits (one for the data and one for the pte). With
large pages, the page tables can be all cached and you only take a tlb
miss and a single cache miss.
So for this contrived workload, you get a ~2X speedup by using large
pages. Obviously real workloads will get less speedup, but it is still
Another way of stating this is that large pages don't just increase the
coverage of the tlb, they also increase the pagetable coverage of the
data cache, which can be much more significant.
to post comments)