mm/memory_hotplug: don't check for "all holes" in shrink_zone_span()

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.

Link: http://lkml.kernel.org/r/20191006085646.5768-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pagupta@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2020-02-03 17:34:16 -08:00 committed by Linus Torvalds
parent 9b05158f5d
commit 950b68d917
1 changed files with 7 additions and 27 deletions

View File

@ -411,6 +411,9 @@ 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) {
/*
@ -423,34 +426,11 @@ 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;
}
}
/*
* 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);
}