Re: [PATCH v6 09/10] mm/memory_hotplug: Drop local variables in shrink_zone_span()

[Wei Yang]

On Sun, Oct 06, 2019 at 10:56:45AM +0200, David Hildenbrand wrote:
>Get rid of the unnecessary local variables.
>
>Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>Cc: Oscar Salvador <osalvador@xxxxxxx>
>Cc: David Hildenbrand <david@xxxxxxxxxx>
>Cc: Michal Hocko <mhocko@xxxxxxxx>
>Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
>Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
>Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
>Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>

Looks reasonable.

Reviewed-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>

>---
> mm/memory_hotplug.c | 15 ++++++---------
> 1 file changed, 6 insertions(+), 9 deletions(-)
>
>diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>index 8dafa1ba8d9f..843481bd507d 100644
>--- a/mm/memory_hotplug.c
>+++ b/mm/memory_hotplug.c
>@@ -374,14 +374,11 @@ static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
> static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> 			     unsigned long end_pfn)
> {
>-	unsigned long zone_start_pfn = zone->zone_start_pfn;
>-	unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
>-	unsigned long zone_end_pfn = z;
> 	unsigned long pfn;
> 	int nid = zone_to_nid(zone);
> 
> 	zone_span_writelock(zone);
>-	if (zone_start_pfn == start_pfn) {
>+	if (zone->zone_start_pfn == start_pfn) {
> 		/*
> 		 * If the section is smallest section in the zone, it need
> 		 * shrink zone->zone_start_pfn and zone->zone_spanned_pages.
>@@ -389,25 +386,25 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn,
> 		 * for shrinking zone.
> 		 */
> 		pfn = find_smallest_section_pfn(nid, zone, end_pfn,
>-						zone_end_pfn);
>+						zone_end_pfn(zone));
> 		if (pfn) {
>+			zone->spanned_pages = zone_end_pfn(zone) - pfn;
> 			zone->zone_start_pfn = pfn;
>-			zone->spanned_pages = zone_end_pfn - pfn;
> 		} else {
> 			zone->zone_start_pfn = 0;
> 			zone->spanned_pages = 0;
> 		}
>-	} else if (zone_end_pfn == end_pfn) {
>+	} else if (zone_end_pfn(zone) == end_pfn) {
> 		/*
> 		 * If the section is biggest section in the zone, it need
> 		 * shrink zone->spanned_pages.
> 		 * In this case, we find second biggest valid mem_section for
> 		 * shrinking zone.
> 		 */
>-		pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn,
>+		pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn,
> 					       start_pfn);
> 		if (pfn)
>-			zone->spanned_pages = pfn - zone_start_pfn + 1;
>+			zone->spanned_pages = pfn - zone->zone_start_pfn + 1;
> 		else {
> 			zone->zone_start_pfn = 0;
> 			zone->spanned_pages = 0;
>-- 
>2.21.0

-- 
Wei Yang
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