svn commit: r210846 - in head/sys/mips: include mips

[Jayachandran C.]

On Thu, Aug 5, 2010 at 4:26 PM, Jayachandran C.
<c.jayachandran at gmail.com> wrote:
> On Thu, Aug 5, 2010 at 11:43 AM, Alan Cox <alc at cs.rice.edu> wrote:
>> Just an observation ...
>>
>> Jayachandran C. wrote:
>>>
>>> Author: jchandra
>>> Date: Wed Aug  4 14:12:09 2010
>>> New Revision: 210846
>>> URL: http://svn.freebsd.org/changeset/base/210846
>>>
>>> Log:
>>>  Add 3 level page tables for MIPS in n64.
>>>    - 32 bit compilation will still use old 2 level page tables
>>>  - re-arrange pmap code so that adding another level is easier
>>>  - pmap code for 3 level page tables for n64
>>>  - update TLB handler to traverse 3 levels in n64
>>>    Reviewed by:        jmallett
>>
>> MIPS doesn't really need to use atomic_cmpset_int() in situations like this
>> because the software dirty bit emulation in trap.c acquires the pmap lock.
>>  Atomics like this appear to be a carryover from i386 where the
>> hardware-managed TLB might concurrently set the modified bit.
>
> Then I guess we should be able to use *pte directly, without pbits,
> obits and the retry loop.
> Will try this change...

Can you have a look at the attached patch and see if it is okay?  This
has the above changes, and I have attempted to fix the other issue you
had reported on wired mapping count too.

There are a few calls for loadandclear() on pte too, with pmap lock
held, can this be avoided too?

Thanks,
JC.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pmap.diff
Type: text/x-patch
Size: 2299 bytes
Desc: not available
Url : http://lists.freebsd.org/pipermail/freebsd-mips/attachments/20100805/c25ba91f/pmap.bin