On Wed, Jul 31, 2019 at 10:03:09AM +0200, Michal Hocko wrote: > On Wed 31-07-19 09:24:21, Mike Rapoport wrote: > > [ sorry for a late reply too, somehow I missed this thread before ] > > > > On Tue, Jul 30, 2019 at 10:14:15AM +0200, Michal Hocko wrote: > > > [Sorry for a late reply] > > > > > > On Mon 15-07-19 17:55:07, Hoan Tran OS wrote: > > > > Hi, > > > > > > > > On 7/12/19 10:00 PM, Michal Hocko wrote: > > > [...] > > > > > Hmm, I thought this was selectable. But I am obviously wrong here. > > > > > Looking more closely, it seems that this is indeed only about > > > > > __early_pfn_to_nid and as such not something that should add a config > > > > > symbol. This should have been called out in the changelog though. > > > > > > > > Yes, do you have any other comments about my patch? > > > > > > Not really. Just make sure to explicitly state that > > > CONFIG_NODES_SPAN_OTHER_NODES is only about __early_pfn_to_nid and that > > > doesn't really deserve it's own config and can be pulled under NUMA. > > > > > > > > Also while at it, does HAVE_MEMBLOCK_NODE_MAP fall into a similar > > > > > bucket? Do we have any NUMA architecture that doesn't enable it? > > > > > > > > > HAVE_MEMBLOCK_NODE_MAP makes huge difference in node/zone initialization > > sequence so it's not only about a singe function. > > The question is whether we want to have this a config option or enable > it unconditionally for each NUMA system. We can make it 'default NUMA', but we can't drop it completely because microblaze uses sparse_memory_present_with_active_regions() which is unavailable when HAVE_MEMBLOCK_NODE_MAP=n. > > > > As I checked with arch Kconfig files, there are 2 architectures, riscv > > > > and microblaze, do not support NUMA but enable this config. > > > > My take would be that riscv will support NUMA some day. > > > > > > And 1 architecture, alpha, supports NUMA but does not enable this config. > > > > alpha's NUMA support is BROKEN for more than a decade now, I doubt it'll > > ever get fixed. > > I can see Al has marked it BROKEN in 2005. Maybe time to rip it out? > Although it doesn't seem to be a lot of code in arch/alpha at first > glance so maybe not worth an effort. > -- > Michal Hocko > SUSE Labs > -- Sincerely yours, Mike.
