[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