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authorOscar Salvador <osalvador@suse.de>2021-05-04 18:39:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-05-05 11:27:26 -0700
commitdd8e2f230d82ecd60504fba48bb10bf3760b674e (patch)
treec067c9fd2f962a71f017d76705024ae126a389d8
parent8736cc2d002f14e90d2b33bc5bef1740f6275ba4 (diff)
mm,memory_hotplug: relax fully spanned sections check
We want {online,offline}_pages to operate on whole memblocks, but memmap_on_memory will poke pageblock_nr_pages aligned holes in the beginning, which is a special case we want to allow. Relax the check to account for that case. Link: https://lkml.kernel.org/r/20210421102701.25051-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memory_hotplug.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 729fba144c71..b8467faf2f69 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -838,9 +838,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages,
int ret;
struct memory_notify arg;
- /* We can only online full sections (e.g., SECTION_IS_ONLINE) */
+ /*
+ * {on,off}lining is constrained to full memory sections (or more
+ * precisly to memory blocks from the user space POV).
+ * memmap_on_memory is an exception because it reserves initial part
+ * of the physical memory space for vmemmaps. That space is pageblock
+ * aligned.
+ */
if (WARN_ON_ONCE(!nr_pages ||
- !IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION)))
+ !IS_ALIGNED(pfn, pageblock_nr_pages) ||
+ !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION)))
return -EINVAL;
mem_hotplug_begin();
@@ -1573,9 +1580,16 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages)
int ret, node;
char *reason;
- /* We can only offline full sections (e.g., SECTION_IS_ONLINE) */
+ /*
+ * {on,off}lining is constrained to full memory sections (or more
+ * precisly to memory blocks from the user space POV).
+ * memmap_on_memory is an exception because it reserves initial part
+ * of the physical memory space for vmemmaps. That space is pageblock
+ * aligned.
+ */
if (WARN_ON_ONCE(!nr_pages ||
- !IS_ALIGNED(start_pfn | nr_pages, PAGES_PER_SECTION)))
+ !IS_ALIGNED(start_pfn, pageblock_nr_pages) ||
+ !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)))
return -EINVAL;
mem_hotplug_begin();