On Fri, Aug 14, 2015 at 3:06 PM, Jerome Glisse <j.glisse(a)gmail.com> wrote:
On Fri, Aug 14, 2015 at 02:52:15PM -0700, Dan Williams wrote:
> On Fri, Aug 14, 2015 at 2:37 PM, Jerome Glisse <j.glisse(a)gmail.com> wrote:
> > On Wed, Aug 12, 2015 at 11:50:05PM -0400, Dan Williams wrote:
> > What is the rational for not updating max_pfn, max_low_pfn,
> The idea is that this memory is not meant to be available to the page
> allocator and should not count as new memory capacity. We're only
> hotplugging it to get struct page coverage.
But this sounds bogus to me to rely on max_pfn to stay smaller than
first_dev_pfn. For instance you might plug a device that register
dev memory and then some regular memory might be hotplug, effectively
updating max_pfn to a value bigger than first_dev_pfn.
Also i do not think that the buddy allocator use max_pfn or
to consider page/zone for allocation or not.
Yes, I took it out with no effects. I'll investigate further whether
we should be touching those variables or not for this new usage.