[PATCH v3 10/12] memory-hotplug: memory_hotplug: clear zone when removing the memory
From: Yasuaki Ishimatsu
When a memory is added, we update zone's and pgdat's start_pfn and
spanned_pages in the function __add_zone(). So we should revert them
when the memory is removed.
The patch adds a new function __remove_zone() to do this.
CC: David Rientjes
CC: Jiang Liu
CC: Len Brown
CC: Christoph Lameter
Cc: Minchan Kim
CC: Andrew Morton
CC: KOSAKI Motohiro
Signed-off-by: Yasuaki Ishimatsu
Signed-off-by: Wen Congyang
---
mm/memory_hotplug.c | 207
1 file changed, 207 insertions(+)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 03153cf..7bcced0 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -312,10 +312,213 @@ static int __meminit __add_section(int nid, struct zone
*zone,
return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
+/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
+static int find_smallest_section_pfn(int nid, struct zone *zone,
+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)))
+ continue;
+
+ if (unlikely(pfn_to_nid(start_pfn) != nid))
+ continue;
+
+ if (zone && zone != page_zone(pfn_to_page(start_pfn)))
+ continue;
+
+ return start_pfn;
+ }
+
+ return 0;
+}
+
+/* find the biggest valid pfn in the range [start_pfn, end_pfn). */
+static int find_biggest_section_pfn(int nid, struct zone *zone,
+ 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)))
+ continue;
+
+ if (unlikely(pfn_to_nid(pfn) != nid))
+ continue;
+
+ if (zone && zone != page_zone(pfn_to_page(pfn)))
+ continue;
+
+ return pfn;
+ }
+
+ return 0;
+}
+
+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 zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
+ unsigned long pfn;
+ struct mem_section *ms;
+ int nid = zone_to_nid(zone);
+
+ zone_span_writelock(zone);
+ if (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.
+* In this case, we find second smallest valid mem_section
+* for shrinking zone.
+*/
+ pfn = find_smallest_section_pfn(nid, zone, end_pfn,
+ zone_end_pfn);
+ if (pfn) {
+ zone->zone_start_pfn = pfn;
+ zone->spanned_pages = zone_end_pfn - pfn;
+ }
+ } else if (zone_end_pfn == 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,
+ start_pfn);
+ if (pfn)
+ zone->spanned_pages = pfn - zone_start_pfn + 1;
+ }
+
+ /*
+* 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_SECTION) {
+ ms = __pfn_to_section(pfn);
+
+ if (unlikely(!valid_section(ms)))
+ continue;
+
+ if (page_zone(pfn_to_page(pfn)) != zone)
+ continue;
+
+/* If the section is current section, it continues the loop */
+ if (start_pfn == pfn)
+ continue;
+
+ /* If we find valid section, we have nothing to do */
+ zone_span_writeunlock(zone);
+
[PATCH v3 10/12] memory-hotplug: memory_hotplug: clear zone when removing the memory
From: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
When a memory is added, we update zone's and pgdat's start_pfn and
spanned_pages in the function __add_zone(). So we should revert them
when the memory is removed.
The patch adds a new function __remove_zone() to do this.
CC: David Rientjes rient...@google.com
CC: Jiang Liu liu...@gmail.com
CC: Len Brown len.br...@intel.com
CC: Christoph Lameter c...@linux.com
Cc: Minchan Kim minchan@gmail.com
CC: Andrew Morton a...@linux-foundation.org
CC: KOSAKI Motohiro kosaki.motoh...@jp.fujitsu.com
Signed-off-by: Yasuaki Ishimatsu isimatu.yasu...@jp.fujitsu.com
Signed-off-by: Wen Congyang we...@cn.fujitsu.com
---
mm/memory_hotplug.c | 207
1 file changed, 207 insertions(+)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 03153cf..7bcced0 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -312,10 +312,213 @@ static int __meminit __add_section(int nid, struct zone
*zone,
return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
+/* find the smallest valid pfn in the range [start_pfn, end_pfn) */
+static int find_smallest_section_pfn(int nid, struct zone *zone,
+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)))
+ continue;
+
+ if (unlikely(pfn_to_nid(start_pfn) != nid))
+ continue;
+
+ if (zone zone != page_zone(pfn_to_page(start_pfn)))
+ continue;
+
+ return start_pfn;
+ }
+
+ return 0;
+}
+
+/* find the biggest valid pfn in the range [start_pfn, end_pfn). */
+static int find_biggest_section_pfn(int nid, struct zone *zone,
+ 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)))
+ continue;
+
+ if (unlikely(pfn_to_nid(pfn) != nid))
+ continue;
+
+ if (zone zone != page_zone(pfn_to_page(pfn)))
+ continue;
+
+ return pfn;
+ }
+
+ return 0;
+}
+
+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 zone_end_pfn = zone-zone_start_pfn + zone-spanned_pages;
+ unsigned long pfn;
+ struct mem_section *ms;
+ int nid = zone_to_nid(zone);
+
+ zone_span_writelock(zone);
+ if (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.
+* In this case, we find second smallest valid mem_section
+* for shrinking zone.
+*/
+ pfn = find_smallest_section_pfn(nid, zone, end_pfn,
+ zone_end_pfn);
+ if (pfn) {
+ zone-zone_start_pfn = pfn;
+ zone-spanned_pages = zone_end_pfn - pfn;
+ }
+ } else if (zone_end_pfn == 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,
+ start_pfn);
+ if (pfn)
+ zone-spanned_pages = pfn - zone_start_pfn + 1;
+ }
+
+ /*
+* 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_SECTION) {
+ ms = __pfn_to_section(pfn);
+
+ if (unlikely(!valid_section(ms)))
+ continue;
+
+ if (page_zone(pfn_to_page(pfn)) != zone)
+ continue;
+
+/* If the section is current section, it continues the loop
