svn commit: r259908 - head/sys/vm

[Alan Cox]

On 12/28/2013 18:02, Nathan Whitehorn wrote:
> On 12/26/13 00:46, Marcel Moolenaar wrote:
>> Author: marcel
>> Date: Thu Dec 26 05:46:10 2013
>> New Revision: 259908
>> URL: http://svnweb.freebsd.org/changeset/base/259908
>>
>> Log:
>>   For ia64, use pmap_remove_pages() and not pmap_remove(). The problem is
>>   that we don't have a good way (yet) to iterate over the mapped pages by
>>   virtual address and simply try each page within the range. Given that we
>>   call pmap_remove() over the entire 2^63 bytes of address space, it takes
>>   a while for pmap_remove to have tried all 2^50 pages.
>>   By using pmap_remove_pages() we use the PV list to find all mappings.
>>   
>>   Change derived from a patch by: alc
>>
> Why make this ia64-specific? It seems like a potentially useful general
> optimization and certainly shouldn't be harmful on other architectures.

Some of the other implementations of pmap_remove_pages() have
limitations that don't permit them to be used for this purpose, e.g.,

        if (pmap != PCPU_GET(curpmap)) {
                printf("warning: pmap_remove_pages called with
non-current pmap\n");
                return;
        }

Alan