svn commit: r233097 - head/sys/amd64/amd64
alc at rice.edu
Sat Mar 17 23:50:00 UTC 2012
On 03/17/2012 17:14, Nathan Whitehorn wrote:
> On Mar 17, 2012, at 5:04 PM, Alan Cox wrote:
>> Author: alc
>> Date: Sat Mar 17 22:04:58 2012
>> New Revision: 233097
>> URL: http://svn.freebsd.org/changeset/base/233097
>> With the changes over the past year to how accesses to the page's dirty
>> field are synchronized, there is no need for pmap_protect() to acquire
>> the page queues lock unless it is going to access the pv lists.
>> Reviewed by: kib
> Under what circumstances does the page queue lock actually have to be
You need it when you are manipulating the pvo_vlink lists. That said,
we are at the point where the PPC/AIM pmap could define its own PVO list
mutex and not (ab)use the page queues mutex for this purpose. Just do a
straightforward, mechanical substitution, and you should be fine.
> It looks like from this that I can remove the page queue lock from the
> PPC/AIM pmap_protect() completely, but I don't have a good sense of it.
Yes, you can this instant remove the acquisition and release of the page
queues lock from this function.
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