Date: Wed, 21 Mar 2001 14:44:31 -0800 From: Chris Sears <cbsears@ix.netcom.com> To: Alexey Dokuchaev <danfe@inet.ssc.nsu.ru> Cc: freebsd-hackers@freebsd.org Subject: Re: Linux -> FreeBSD VM functions Message-ID: <3AB92ECF.EAACE3D8@ix.netcom.com> References: <Pine.LNX.4.10.10103212233240.22100-100000@inet.ssc.nsu.ru>
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Alexey
> static inline unsigned long
> get_kvirt_address(unsigned long address)
> {
> }
This function returns 0 if a virtual address is not mapped.
Otherwise it returns the linear address associated
with that virtual address by traversing the page table
and extracting the physical address from mem_map,
the reverse-mapped software pagetable.
> Is simple PHYS_TO_VM_PAGE will do?
No actually it would the other way around: VM_PAGE_TO_PHYS.
But you have to get the vm_page of the virtual address first.
Perhaps pmap_extract(pmap, va) might be more helpful
but you will need the pmap of the process.
> if (PageReserved(mem_map + GET_MAP_NR(page))) { ... }
PG_reserved means that the page is reserved to the kernel.
*Maybe* PG_UNMANAGED might be analogous.
>
> /* Page flag bit values */
> #define PG_locked 0
> #define PG_error 1
> #define PG_referenced 2
> #define PG_dirty 3
> #define PG_uptodate 4
> #define PG_free_after 5
> #define PG_decr_after 6
> #define PG_swap_unlock_after 7
> #define PG_DMA 8
> #define PG_Slab 9
> #define PG_swap_cache 10
> #define PG_skip 11
> #define PG_reserved 31
>
> How do those relate to FreeBSD vision of things?
Look at vm_page.h
You should spend some quality time with Understanding the Linux Kernel
especially chapter 6, and/or the Linux Commentary. And chapter 5
of Design and Implementation of 4.4BSD. And since the 4.4BSD vm
is really the Mach vm you should look at that stuff too.
Chris
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