On Fri, Aug 14, 2015 at 3:06 PM, Jerome Glisse <j.glisse@xxxxxxxxx> 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@xxxxxxxxx> 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. > True. > Also i do not think that the buddy allocator use max_pfn or max_low_pfn > 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>