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mm,memory_hotplug: relax fully spanned sections check

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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>
This commit is contained in:
Oscar Salvador 2021-05-04 18:39:36 -07:00 committed by Linus Torvalds
parent 8736cc2d00
commit dd8e2f230d
1 changed files with 18 additions and 4 deletions
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22
mm/memory_hotplug.c
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@ -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();