The patch titled
Subject: mm/memory_hotplug: simplify online_pages_range()
has been added to the -mm tree. Its filename is
mm-memory_hotplug-simplify-online_pages_range.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-simplify-online_pages_range.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-simplify-online_pages_range.patch
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: mm/memory_hotplug: simplify online_pages_range()
move_pfn_range_to_zone() will set all pages to PG_reserved via
memmap_init_zone(). The only way a page could no longer be reserved would
be if a MEM_GOING_ONLINE notifier would clear PG_reserved - which is not
done (the online_page callback is used for that purpose by e.g., Hyper-V
instead). walk_system_ram_range() will never call online_pages_range()
with duplicate PFNs, so drop the PageReserved() check.
Simplify the handling, as online_pages always corresponds to nr_pages.
There is no need for online_pages_blocks() anymore.
Link: http://lkml.kernel.org/r/20190809125701.3316-4-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Arun KS <arunks@xxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 44 ++++++++++++++++++------------------------
1 file changed, 19 insertions(+), 25 deletions(-)
--- a/mm/memory_hotplug.c~mm-memory_hotplug-simplify-online_pages_range
+++ a/mm/memory_hotplug.c
@@ -632,37 +632,31 @@ static void generic_online_page(struct p
#endif
}
-static int online_pages_blocks(unsigned long start, unsigned long nr_pages)
+static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
+ void *arg)
{
- unsigned long end = start + nr_pages;
- int order, onlined_pages = 0;
-
- while (start < end) {
- order = min(MAX_ORDER - 1,
- get_order(PFN_PHYS(end) - PFN_PHYS(start)));
+ const unsigned long end_pfn = start_pfn + nr_pages;
+ unsigned long pfn;
+ int order;
+
+ /*
+ * Online the pages. The callback might decide to keep some pages
+ * PG_reserved (to add them to the buddy later), but we still account
+ * them as being online/belonging to this zone ("present").
+ */
+ for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) {
+ order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn)));
/* make sure the PFN is aligned and we don't exceed the range */
- while (!IS_ALIGNED(start, 1ul << order) ||
- (1ul << order) > end - start)
+ while (!IS_ALIGNED(start_pfn, 1ul << order) ||
+ (1ul << order) > end_pfn - pfn)
order--;
- (*online_page_callback)(pfn_to_page(start), order);
-
- onlined_pages += (1UL << order);
- start += (1UL << order);
+ (*online_page_callback)(pfn_to_page(pfn), order);
}
- return onlined_pages;
-}
-
-static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
- void *arg)
-{
- unsigned long onlined_pages = *(unsigned long *)arg;
-
- if (PageReserved(pfn_to_page(start_pfn)))
- onlined_pages += online_pages_blocks(start_pfn, nr_pages);
- online_mem_sections(start_pfn, start_pfn + nr_pages);
+ /* mark all involved sections as online */
+ online_mem_sections(start_pfn, end_pfn);
- *(unsigned long *)arg = onlined_pages;
+ *(unsigned long *)arg += nr_pages;
return 0;
}
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-memory_hotplug-remove-move_pfn_range.patch
drivers-base-nodec-simplify-unregister_memory_block_under_nodes.patch
drivers-base-memoryc-fixup-documentation-of-removable-phys_index-block_size_bytes.patch
driver-base-memoryc-validate-memory-block-size-early.patch
resource-use-pfn_up-pfn_down-in-walk_system_ram_range.patch
mm-memory_hotplug-handle-unaligned-start-and-nr_pages-in-online_pages_blocks.patch
mm-memory_hotplug-simplify-online_pages_range.patch
mm-memory_hotplug-online_pages-cannot-be-0-in-online_pages.patch
