Messages in this thread | | | Date | Mon, 7 Feb 2022 15:50:54 +0100 | Subject | Re: [PATCH 2/4] mm/memory_hotplug: avoid calling zone_intersects() for ZONE_NORMAL | From | David Hildenbrand <> |
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On 07.02.22 14:36, Miaohe Lin wrote: > If zid reaches ZONE_NORMAL, the caller will always get the NORMAL zone no > matter what zone_intersects() returns. So we can save some possible cpu > cycles by avoid calling zone_intersects() for ZONE_NORMAL. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > mm/memory_hotplug.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index cbc67c27e0dd..140809e60e9a 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -826,7 +826,7 @@ static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn > struct pglist_data *pgdat = NODE_DATA(nid); > int zid; > > - for (zid = 0; zid <= ZONE_NORMAL; zid++) { > + for (zid = 0; zid < ZONE_NORMAL; zid++) { > struct zone *zone = &pgdat->node_zones[zid]; > > if (zone_intersects(zone, start_pfn, nr_pages))
Makes sense, although we just don't care about the CPU cycles at that point.
Reviewed-by: David Hildenbrand <david@redhat.com>
-- Thanks,
David / dhildenb
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