On Tue 07-12-21 16:34:30, David Hildenbrand wrote:
On 07.12.21 16:29, Michal Hocko wrote:
On Tue 07-12-21 16:09:39, David Hildenbrand wrote:
On 07.12.21 14:23, Michal Hocko wrote:
On Tue 07-12-21 13:28:31, David Hildenbrand wrote: [...]
But maybe I am missing something important regarding online vs. offline nodes that your patch changes?
I am relying on alloc_node_data setting the node online. But if we are to change the call to arch_alloc_node_data then the patch needs to be more involved. Here is what I have right now. If this happens to be the right way then there is some additional work to sync up with the hotplug code.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c5952749ad40..a296e934ad2f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8032,8 +8032,23 @@ void __init free_area_init(unsigned long *max_zone_pfn) /* Initialise every node */ mminit_verify_pageflags_layout(); setup_nr_node_ids();
- for_each_online_node(nid) {
pg_data_t *pgdat = NODE_DATA(nid);
- for_each_node(nid) {
pg_data_t *pgdat;if (!node_online(nid)) {pr_warn("Node %d uninitialized by the platform. Please report with memory map.\n", nid);pgdat = arch_alloc_nodedata(nid);pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat);arch_refresh_nodedata(nid, pgdat);node_set_online(nid);Setting all possible nodes online might result in quite some QE noice, because all these nodes will then be visible in the sysfs and try_offline_nodes() is essentially for the trash.
I am not sure I follow. I believe sysfs will not get populate because I do not call register_one_node.
arch/x86/kernel/topology.c:topology_init()
for_each_online_node(i) register_one_node(i);
Right you are.
You are right that try_offline_nodes will be reduce which is good imho. More changes will be possible (hopefully to drop some ugly code) on top of this change (or any other that achieves that there are no NULL pgdat for possible nodes).
No to exposing actually offline nodes to user space via sysfs.
Why is that a problem with the sysfs for non-populated nodes?