Re: [PATCH v3] mm: fix panic in __alloc_pages
From: Michal Hocko <mhocko@suse.com>
Date: 2021-12-13 15:06:37
Also in:
linux-mm, lkml
Subsystem:
memory hot(un)plug, memory management, the rest · Maintainers:
David Hildenbrand, Oscar Salvador, Andrew Morton, Linus Torvalds
On Thu 09-12-21 11:48:42, Michal Hocko wrote: [...]
quoted hunk ↗ jump to hunk
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 852041f6be41..2d38a431f62f 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c@@ -1161,19 +1161,21 @@ static void reset_node_present_pages(pg_data_t *pgdat) } /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ -static pg_data_t __ref *hotadd_new_pgdat(int nid) +static pg_data_t __ref *hotadd_init_pgdat(int nid) { struct pglist_data *pgdat; pgdat = NODE_DATA(nid); - if (!pgdat) { - pgdat = arch_alloc_nodedata(nid); - if (!pgdat) - return NULL; + /* + * NODE_DATA is preallocated (free_area_init) but its internal + * state is not allocated completely. Add missing pieces. + * Completely offline nodes stay around and they just need + * reintialization. + */ + if (!pgdat->per_cpu_nodestats) { pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); - arch_refresh_nodedata(nid, pgdat);
This should really be
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 42211485bcf3..2daa88ce8c80 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c@@ -1173,7 +1173,7 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid) * Completely offline nodes stay around and they just need * reintialization. */ - if (!pgdat->per_cpu_nodestats) { + if (pgdat->per_cpu_nodestats == &boot_nodestats) { pgdat->per_cpu_nodestats = alloc_percpu(struct per_cpu_nodestat); } else {
--
Michal Hocko
SUSE Labs