Re: [PATCH] 16K page size in 32 bit kernel

[Songmao Tian <tiansm@lemote.com>]

Ralf Baechle wrote:
> On Tue, Jul 31, 2007 at 05:09:51PM +0400, Dajie Tan wrote:
>
>   
> > 32-bit Kernel for loongson2e currently use 16KB page size to avoid
> > cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
> >
> > Using 22 in 16K page size do not lead to a serious problem but the number
> > of pages allocated for page table is more than previous. (cat
> > /proc/vmstat | grep nr_page_table_pages)
> >
> > It's been tested on FuLong mini PC(loongson2e inside).
> >     
> Looking good, applied.  Thanks!
>
> Did by coincidence any of you try 64K pages with a 32-bit kernel?
>
>   Ralf
>
>
>
>   
I think the following is more complete?

#ifdef CONFIG_64BIT_PHYS_ADDR
-#define PGDIR_SHIFT    21
+#define PGDIR_SHIFT    (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
#else
-#define PGDIR_SHIFT    22
+#define PGDIR_SHIFT    (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
#endif