svn commit: r260898 - head/sys/kern

[John Baldwin]

On Thursday, January 23, 2014 2:35:54 am Adrian Chadd wrote:
> On 22 January 2014 20:34, Rui Paulo <rpaulo at freebsd.org> wrote:
> > On 22 Jan 2014, at 20:05, Adrian Chadd <adrian.chadd at gmail.com> wrote:
> >
> >> .. Make it be an offset into the table rather than a pointer, then we can 
do dirty rcu style hacks to just replace and grow the table as we need more 
memory.
> >>
> >> Don't we have a standard way to pull memory from the top of the physmem 
area early on for allocations like this?
> >
> > Perhaps a bit overkill for this problem?
> 
> We already have platform dependent ways of doing this in the VM init
> path for exactly this - structures needed early at boot.
> 
> It may be overkill but it may also be the cleanest way to allow
> boot-time tuned things based on early available information, which we
> may want to do when it's time to boot a single kernel on a 2-core atom
> board or a 256 core intel/amd server board.

The number of witness structures (WITNESS_COUNT) should not vary in those
cases.

-- 
John Baldwin