The patch titled
Subject: mm,memory_hotplug: relax fully spanned sections check
has been added to the -mm tree. Its filename is
mmmemory_hotplug-relax-fully-spanned-sections-check.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mmmemory_hotplug-relax-fully-spanned-sections-check.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mmmemory_hotplug-relax-fully-spanned-sections-check.patch
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------------------------------------------------------
From: Oscar Salvador <osalvador@xxxxxxx>
Subject: 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@xxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
--- a/mm/memory_hotplug.c~mmmemory_hotplug-relax-fully-spanned-sections-check
+++ a/mm/memory_hotplug.c
@@ -838,9 +838,16 @@ int __ref online_pages(unsigned long pfn
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 st
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();
_
Patches currently in -mm which might be from osalvador@xxxxxxx are
x86-vmemmap-drop-handling-of-4k-unaligned-vmemmap-range.patch
x86-vmemmap-drop-handling-of-1gb-vmemmap-ranges.patch
x86-vmemmap-handle-unpopulated-sub-pmd-ranges.patch
x86-vmemmap-handle-unpopulated-sub-pmd-ranges-fix.patch
x86-vmemmap-optimize-for-consecutive-sections-in-partial-populated-pmds.patch
mmpage_alloc-bail-out-earlier-on-enomem-in-alloc_contig_migrate_range.patch
mmcompaction-let-isolate_migratepages_rangeblock-return-error-codes.patch
mmhugetlb-drop-clearing-of-flag-from-prep_new_huge_page.patch
mmhugetlb-split-prep_new_huge_page-functionality.patch
mm-make-alloc_contig_range-handle-free-hugetlb-pages.patch
mm-make-alloc_contig_range-handle-in-use-hugetlb-pages.patch
mmpage_alloc-drop-unnecessary-checks-from-pfn_range_valid_contig.patch
drivers-base-memory-introduce-memory_block_onlineoffline.patch
mmmemory_hotplug-relax-fully-spanned-sections-check.patch
mmmemory_hotplug-allocate-memmap-from-the-added-memory-range.patch
acpimemhotplug-enable-mhp_memmap_on_memory-when-supported.patch
mmmemory_hotplug-add-kernel-boot-option-to-enable-memmap_on_memory.patch
x86-kconfig-introduce-arch_mhp_memmap_on_memory_enable.patch
arm64-kconfig-introduce-arch_mhp_memmap_on_memory_enable.patch
