block sizes > 4K ?? possible w/large page support?

[Stefan Ring]

> I know we can use hugepages with these sizes, but didn't know we can use this as
> common usage. I tried to look at MM code and didn't find anything which would
> make PAGE_SIZE greater than 4096 (at least in x86), but well, I'm not a MM
> developer too.

Me neither, but so much I think I know. With rather recent kernels,
huge pages are used automatically for "normal" memory. There's a
background thread that tries to locate or create adjacent blocks of
memory and create huge pages from these.

But the normal page size as a unit of allocation is still 4KB, and
this will never change (with the current hardware). The page size of
4KB is hard-wired into the architecture, and I'm not aware of any
extension that allows to change that.