svn commit: r361336 - head/sys/powerpc/aim

[Mark Johnston]

On Thu, May 21, 2020 at 03:53:17PM +0000, Brandon Bergren wrote:
> Author: bdragon
> Date: Thu May 21 15:53:16 2020
> New Revision: 361336
> URL: https://svnweb.freebsd.org/changeset/base/361336
> 
> Log:
>   [PowerPC] Fix kernel boot on powerpc
>   
>   Recent changes have caused the vmspace objects to start coming from KVA
>   instead of direct-mapped memory on powerpc. As far as I can tell, this is
>   not actually a problem, so we should stop arbitrarily asserting that it is.
>   
>   I do not know why this was not being triggered before.

UMA was recently changed in r357549 to use multi-page slabs if doing so
would reduce internal fragmentation to a certain degree.  In that case
the slabs will be mapped into KVA. vmspace objects are quite large but
smaller than a page, so they benefit from this.  You can verify by
checking the vm.uma.VMSPACE.keg.ppera sysctl, which gives the number of
pages per slab.