[PATCH v1] mm/memory_hotplug: Easier calculation to get pages to next section boundary

From: David Hildenbrand
Date: Wed Feb 05 2020 - 08:53:05 EST


Let's use a calculation that's easier to understand and calculates the
same result. Reusing existing macros makes this look nicer.

We always want to have the number of pages (> 0) to the next section
boundary, starting from the current pfn.

Suggested-by: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/memory_hotplug.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 0a54ffac8c68..c30191183c04 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -528,7 +528,8 @@ void __remove_pages(unsigned long pfn, unsigned long nr_pages,
for (; pfn < end_pfn; pfn += cur_nr_pages) {
cond_resched();
/* Select all remaining pages up to the next section boundary */
- cur_nr_pages = min(end_pfn - pfn, -(pfn | PAGE_SECTION_MASK));
+ cur_nr_pages = min(end_pfn - pfn,
+ SECTION_ALIGN_UP(pfn + 1) - pfn);
__remove_section(pfn, cur_nr_pages, map_offset, altmap);
map_offset = 0;
}
--
2.24.1