On 10/06/19 at 10:56am, David Hildenbrand wrote: > If we have holes, the holes will automatically get detected and removed > once we remove the next bigger/smaller section. The extra checks can > go. > > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Oscar Salvador <osalva...@suse.de> > Cc: Michal Hocko <mho...@suse.com> > Cc: David Hildenbrand <da...@redhat.com> > Cc: Pavel Tatashin <pasha.tatas...@soleen.com> > Cc: Dan Williams <dan.j.willi...@intel.com> > Cc: Wei Yang <richardw.y...@linux.intel.com> > Signed-off-by: David Hildenbrand <da...@redhat.com> > --- > mm/memory_hotplug.c | 34 +++++++--------------------------- > 1 file changed, 7 insertions(+), 27 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index f294918f7211..8dafa1ba8d9f 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned > long start_pfn, > if (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) { > /* > @@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, > unsigned long start_pfn, > start_pfn); > if (pfn) > zone->spanned_pages = pfn - zone_start_pfn + 1; > + else { > + zone->zone_start_pfn = 0; > + zone->spanned_pages = 0;
Thinking in which case (zone_start_pfn != start_pfn) and it comes here. > + } > } > - > - /* > - * The section is not biggest or smallest mem_section in the zone, it > - * only creates a hole in the zone. So in this case, we need not > - * change the zone. But perhaps, the zone has only hole data. Thus > - * it check the zone has only hole or not. > - */ > - pfn = zone_start_pfn; > - for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { > - if (unlikely(!pfn_to_online_page(pfn))) > - continue; > - > - if (page_zone(pfn_to_page(pfn)) != zone) > - continue; > - > - /* Skip range to be removed */ > - if (pfn >= start_pfn && pfn < end_pfn) > - continue; > - > - /* If we find valid section, we have nothing to do */ > - zone_span_writeunlock(zone); > - return; > - } > - > - /* The zone has no valid section */ > - zone->zone_start_pfn = 0; > - zone->spanned_pages = 0; > zone_span_writeunlock(zone); > } > > -- > 2.21.0 > >