On 06.04.21 13:11, Oscar Salvador wrote:
When using self-hosted vmemmap pages, the number of pages passed to
{online,offline}_pages might not fully span sections, but they always
fully span pageblocks.
Relax the check account for that case.
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
mm/memory_hotplug.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0cdbbfbc5757..5fe3e3942b19 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -838,9 +838,13 @@ 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) */
+ /* We can only offline full sections (e.g., SECTION_IS_ONLINE).
+ * However, when using e.g: memmap_on_memory, some pages are initialized
+ * prior to calling in here. The remaining amount of pages must be
+ * pageblock aligned.
+ */
if (WARN_ON_ONCE(!nr_pages ||
- !IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION)))
+ !IS_ALIGNED(pfn | nr_pages, pageblock_nr_pages)))
return -EINVAL;
mem_hotplug_begin();
@@ -1573,9 +1577,13 @@ 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) */
+ /* We can only offline full sections (e.g., SECTION_IS_ONLINE).
+ * However, when using e.g: memmap_on_memory, some pages are initialized
+ * prior to calling in here. The remaining amount of pages must be
+ * pageblock aligned.
+ */
if (WARN_ON_ONCE(!nr_pages ||
- !IS_ALIGNED(start_pfn | nr_pages, PAGES_PER_SECTION)))
+ !IS_ALIGNED(start_pfn | nr_pages, pageblock_nr_pages)))
return -EINVAL;
mem_hotplug_begin();
I'd only relax start_pfn. That way the function is pretty much
impossible to abuse for sub-section onlining/offlining.
if (WARN_ON_ONCE(!nr_pages ||
!IS_ALIGNED(start_pfn, pageblock_nr_pages))
!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)))
--
Thanks,
David / dhildenb
