RE: Who owns those locks ?

From: Luck, Tony
Date: Wed May 12 2004 - 06:46:25 EST

>The first reason to use a shift of 12 bits is:
>you can see easily what the address of the owner's task structure is.
>In addition, with page size of 16 Kbytes, you've got only 16 Tbytes
>in the identity mapped kernel address space any way.
>Should we move to a page size of 64 Kbytes, you can use a shift of
>16 bits and you keep the address human readable ;-)

Human readable is nice.

The identity mapped kernel space is not limited by the pagesize.
Mappings in region 7[*] are provided by the Alt-dtlb miss handler,
which just inserts a kernel granule sized mapping into the TLB
to cover any TLB miss.


[*] except for the percpu area in the top 64k of region 7 which is
mapped by a locked entry in a DTR register.
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