Re: speed difference between using hard-linked and modular drives?

[Andi Kleen]

> You can see the average depth of the get_free_page hash is way too deep.
> I agree there are a lot of pagecache pages (17GB in the gfp test and 21GB
> in the vmalloc test), but we have to make use of the 32GB of RAM :)

Thanks for the information. I guess the fix for your case would be then
to use the bootmem allocator for allocating the page table hash.
It should have no problems with very large continuous tables, assuming
you have the (physically continuous) memory.

Another possibility would be to switch to some tree/skiplist, but that's 
probably too radical and may have other problems on smaller boxes.

-Andi