uma_small_alloc from direct mapped memory.

[Alan Cox]

Jayachandran C. wrote:
> Hi all,
>
> The attached patch uses the mechanism used to allocate page table
> pages for UMA small allocations too.  This will make sure that all the
> small UMA allocations comes from KSEG0 pages in 32 bit and XKPHYS in
> 64bit.
>
> This reduces TLB misses in kernel code significantly, and can give
> major performance advantage for applications that spent a lot of time
> in kernel.
>
> Please let me know your comments.
>
>   

It looks ok.  My only suggested change is that you follow the precedent 
of amd64, ia64, and powerpc, and place uma_small_alloc() and 
uma_small_free() in a new file, mips/mips/uma_machdep.c.

Alan