From: wency@cn.fujitsu.com
To: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org,
linux-s390@vger.kernel.org, linux-sh@vger.kernel.org,
linux-ia64@vger.kernel.org, cmetcalf@tilera.com,
sparclinux@vger.kernel.org
Cc: len.brown@intel.com, Wen Congyang <wency@cn.fujitsu.com>,
isimatu.yasuaki@jp.fujitsu.com, paulus@samba.org,
minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com,
rientjes@google.com, cl@linux.com, akpm@linux-foundation.org,
liuj97@gmail.com
Subject: [PATCH v2 10/12] memory-hotplug: memory_hotplug: clear zone when removing the memory
Date: Tue, 23 Oct 2012 18:30:48 +0800 [thread overview]
Message-ID: <1350988250-31294-11-git-send-email-wency@cn.fujitsu.com> (raw)
In-Reply-To: <1350988250-31294-1-git-send-email-wency@cn.fujitsu.com>
From: Yasuaki Ishimatsu <isimatu.yasuaki@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 <rientjes@google.com>
CC: Jiang Liu <liuj97@gmail.com>
CC: Len Brown <len.brown@intel.com>
CC: Christoph Lameter <cl@linux.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
mm/memory_hotplug.c | 207 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 207 insertions(+), 0 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 03153cf..55a228d 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);
+ return;
+ }
+
+ /* The zone has no valid section */
+ zone->zone_start_pfn = 0;
+ zone->spanned_pages = 0;
+ zone_span_writeunlock(zone);
+}
+
+static void shrink_pgdat_span(struct pglist_data *pgdat,
+ unsigned long start_pfn, unsigned long end_pfn)
+{
+ unsigned long pgdat_start_pfn = pgdat->node_start_pfn;
+ unsigned long pgdat_end_pfn =
+ pgdat->node_start_pfn + pgdat->node_spanned_pages;
+ unsigned long pfn;
+ struct mem_section *ms;
+ int nid = pgdat->node_id;
+
+ if (pgdat_start_pfn == start_pfn) {
+ /*
+ * If the section is smallest section in the pgdat, it need
+ * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages.
+ * In this case, we find second smallest valid mem_section
+ * for shrinking zone.
+ */
+ pfn = find_smallest_section_pfn(nid, NULL, end_pfn,
+ pgdat_end_pfn);
+ if (pfn) {
+ pgdat->node_start_pfn = pfn;
+ pgdat->node_spanned_pages = pgdat_end_pfn - pfn;
+ }
+ } else if (pgdat_end_pfn == end_pfn) {
+ /*
+ * If the section is biggest section in the pgdat, it need
+ * shrink pgdat->node_spanned_pages.
+ * In this case, we find second biggest valid mem_section for
+ * shrinking zone.
+ */
+ pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn,
+ start_pfn);
+ if (pfn)
+ pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1;
+ }
+
+ /*
+ * If the section is not biggest or smallest mem_section in the pgdat,
+ * it only creates a hole in the pgdat. So in this case, we need not
+ * change the pgdat.
+ * But perhaps, the pgdat has only hole data. Thus it check the pgdat
+ * 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)))
+ continue;
+
+ if (pfn_to_nid(pfn) != nid)
+ 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 */
+ return;
+ }
+
+ /* The pgdat has no valid section */
+ pgdat->node_start_pfn = 0;
+ pgdat->node_spanned_pages = 0;
+}
+
+static void __remove_zone(struct zone *zone, unsigned long start_pfn)
+{
+ struct pglist_data *pgdat = zone->zone_pgdat;
+ int nr_pages = PAGES_PER_SECTION;
+ int zone_type;
+ unsigned long flags;
+
+ zone_type = zone - pgdat->node_zones;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
+ shrink_zone_span(zone, start_pfn, start_pfn + nr_pages);
+ shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages);
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+}
+
static int __remove_section(struct zone *zone, struct mem_section *ms)
{
unsigned long flags;
struct pglist_data *pgdat = zone->zone_pgdat;
+ unsigned long start_pfn;
+ int scn_nr;
int ret = -EINVAL;
if (!valid_section(ms))
@@ -325,6 +528,10 @@ static int __remove_section(struct zone *zone, struct mem_section *ms)
if (ret)
return ret;
+ scn_nr = __section_nr(ms);
+ start_pfn = section_nr_to_pfn(scn_nr);
+ __remove_zone(zone, start_pfn);
+
pgdat_resize_lock(pgdat, &flags);
sparse_remove_one_section(zone, ms);
pgdat_resize_unlock(pgdat, &flags);
--
1.7.1
next prev parent reply other threads:[~2012-10-23 10:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 10:30 [PATCH v2 00/12] memory-hotplug: hot-remove physical memory wency
2012-10-23 10:30 ` Ni zhan Chen
2012-10-23 10:39 ` Wen Congyang
2012-10-23 10:30 ` [PATCH v2 01/12] memory-hotplug: try to offline the memory twice to avoid dependence wency
2012-10-23 10:30 ` [PATCH v2 02/12] memory-hotplug: check whether all memory blocks are offlined or not when removing memory wency
2012-10-23 10:30 ` [PATCH v2 03/12] memory-hotplug: remove redundant codes wency
2012-10-23 10:30 ` [PATCH v2 04/12] memory-hotplug: remove /sys/firmware/memmap/X sysfs wency
2012-10-23 10:30 ` [PATCH v2 05/12] memory-hotplug: introduce new function arch_remove_memory() for removing page table depends on architecture wency
2012-10-23 10:30 ` [PATCH v2 06/12] memory-hotplug: unregister memory section on SPARSEMEM_VMEMMAP wency
2012-10-23 10:30 ` [PATCH v2 07/12] memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap wency
2012-10-23 10:30 ` [PATCH v2 08/12] memory-hotplug: remove memmap " wency
2012-10-23 10:30 ` [PATCH v2 09/12] memory-hotplug: remove page table of x86_64 architecture wency
2012-10-23 10:30 ` wency [this message]
2012-10-29 15:34 ` [PATCH v2 10/12] memory-hotplug: memory_hotplug: clear zone when removing the memory Jianguo Wu
2012-10-30 1:50 ` Wen Congyang
2012-11-07 7:40 ` [PATCH] Update start_pfn in zone and pg_data when spanned_pages == 0 Tang Chen
2012-10-23 10:30 ` [PATCH v2 11/12] memory-hotplug: remove sysfs file of node wency
2012-10-23 10:30 ` [PATCH v2 12/12] memory-hotplug: free node_data when a node is offlined wency
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