Commit c8d462c8 authored by Tang Chen's avatar Tang Chen Committed by Luis Henriques

mem-hotplug: reset node present pages when hot-adding a new pgdat

commit 0bd85420 upstream.

When memory is hot-added, all the memory is in offline state.  So clear
all zones' present_pages because they will be updated in online_pages()
and offline_pages().  Otherwise, /proc/zoneinfo will corrupt:

When the memory of node2 is offline:

  # cat /proc/zoneinfo
  ......
  Node 2, zone   Movable
  ......
        spanned  8388608
        present  8388608
        managed  0

When we online memory on node2:

  # cat /proc/zoneinfo
  ......
  Node 2, zone   Movable
  ......
        spanned  8388608
        present  16777216
        managed  8388608
Signed-off-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: default avatarYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 0cc5277d
...@@ -1064,6 +1064,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ ...@@ -1064,6 +1064,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
} }
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
static void reset_node_present_pages(pg_data_t *pgdat)
{
struct zone *z;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->present_pages = 0;
pgdat->node_present_pages = 0;
}
/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
{ {
...@@ -1102,6 +1112,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) ...@@ -1102,6 +1112,13 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
*/ */
reset_node_managed_pages(pgdat); reset_node_managed_pages(pgdat);
/*
* When memory is hot-added, all the memory is in offline state. So
* clear all zones' present_pages because they will be updated in
* online_pages() and offline_pages().
*/
reset_node_present_pages(pgdat);
return pgdat; return pgdat;
} }
......
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