From: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal
Sub-section hotplug support reduces the unit of operation of hotplug from
section-sized-units (PAGES_PER_SECTION) to sub-section-sized units
(PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider
PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not
valid_section(), can toggle.
[osalvador@xxxxxxx: fix shrink_{zone,node}_span]
Link: http://lkml.kernel.org/r/20190717090725.23618-3-osalvador@xxxxxxx
Link: http://lkml.kernel.org/r/156092351496.979959.12703722803097017492.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Reviewed-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> [ppc64]
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 37 ++++++++++++-------------------------
1 file changed, 12 insertions(+), 25 deletions(-)
--- a/mm/memory_hotplug.c~mm-hotplug-prepare-shrink_zone-pgdat_span-for-sub-section-removal
+++ a/mm/memory_hotplug.c
@@ -318,12 +318,8 @@ static unsigned long find_smallest_secti
unsigned long start_pfn,
unsigned long end_pfn)
{
- struct mem_section *ms;
-
- for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) {
- ms = __pfn_to_section(start_pfn);
-
- if (unlikely(!valid_section(ms)))
+ for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) {
+ if (unlikely(!pfn_valid(start_pfn)))
continue;
if (unlikely(pfn_to_nid(start_pfn) != nid))
@@ -343,15 +339,12 @@ static unsigned long find_biggest_sectio
unsigned long start_pfn,
unsigned long end_pfn)
{
- struct mem_section *ms;
unsigned long pfn;
/* pfn is the end pfn of a memory section. */
pfn = end_pfn - 1;
- for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) {
- ms = __pfn_to_section(pfn);
-
- if (unlikely(!valid_section(ms)))
+ for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) {
+ if (unlikely(!pfn_valid(pfn)))
continue;
if (unlikely(pfn_to_nid(pfn) != nid))
@@ -373,7 +366,6 @@ static void shrink_zone_span(struct zone
unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */
unsigned long zone_end_pfn = z;
unsigned long pfn;
- struct mem_section *ms;
int nid = zone_to_nid(zone);
zone_span_writelock(zone);
@@ -410,17 +402,15 @@ static void shrink_zone_span(struct zone
* it check the zone has only hole or not.
*/
pfn = zone_start_pfn;
- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) {
- ms = __pfn_to_section(pfn);
-
- if (unlikely(!valid_section(ms)))
+ for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) {
+ if (unlikely(!pfn_valid(pfn)))
continue;
if (page_zone(pfn_to_page(pfn)) != zone)
continue;
- /* If the section is current section, it continues the loop */
- if (start_pfn == pfn)
+ /* Skip range to be removed */
+ if (pfn >= start_pfn && pfn < end_pfn)
continue;
/* If we find valid section, we have nothing to do */
@@ -441,7 +431,6 @@ static void shrink_pgdat_span(struct pgl
unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */
unsigned long pgdat_end_pfn = p;
unsigned long pfn;
- struct mem_section *ms;
int nid = pgdat->node_id;
if (pgdat_start_pfn == start_pfn) {
@@ -478,17 +467,15 @@ static void shrink_pgdat_span(struct pgl
* has only hole or not.
*/
pfn = pgdat_start_pfn;
- for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) {
- ms = __pfn_to_section(pfn);
-
- if (unlikely(!valid_section(ms)))
+ for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SUBSECTION) {
+ if (unlikely(!pfn_valid(pfn)))
continue;
if (pfn_to_nid(pfn) != nid)
continue;
- /* If the section is current section, it continues the loop */
- if (start_pfn == pfn)
+ /* Skip range to be removed */
+ if (pfn >= start_pfn && pfn < end_pfn)
continue;
/* If we find valid section, we have nothing to do */
_
