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authorTang Chen <tangchen@cn.fujitsu.com>2014-11-13 15:19:39 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-11-13 16:17:06 -0800
commitf784a3f19613901ca4539a5b0eed3bdc700e6ee7 (patch)
tree72044d05a22b521955909c7e9f1e9510064f9abb
parent57cbc87e03c2f473d8f0579186c078ee06f48f2c (diff)
downloadlwn-f784a3f19613901ca4539a5b0eed3bdc700e6ee7.tar.gz
lwn-f784a3f19613901ca4539a5b0eed3bdc700e6ee7.zip
mem-hotplug: reset node managed pages when hot-adding a new pgdat
In free_area_init_core(), zone->managed_pages is set to an approximate value for lowmem, and will be adjusted when the bootmem allocator frees pages into the buddy system. But free_area_init_core() is also called by hotadd_new_pgdat() when hot-adding memory. As a result, zone->managed_pages of the newly added node's pgdat is set to an approximate value in the very beginning. Even if the memory on that node has node been onlined, /sys/device/system/node/nodeXXX/meminfo has wrong value: hot-add node2 (memory not onlined) cat /sys/device/system/node/node2/meminfo Node 2 MemTotal: 33554432 kB Node 2 MemFree: 0 kB Node 2 MemUsed: 33554432 kB Node 2 Active: 0 kB This patch fixes this problem by reset node managed pages to 0 after hot-adding a new node. 1. Move reset_managed_pages_done from reset_node_managed_pages() to reset_all_zones_managed_pages() 2. Make reset_node_managed_pages() non-static 3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat is initialized Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: <stable@vger.kernel.org> [3.16+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/bootmem.h1
-rw-r--r--mm/bootmem.c9
-rw-r--r--mm/memory_hotplug.c9
-rw-r--r--mm/nobootmem.c8
4 files changed, 20 insertions, 7 deletions
diff --git a/include/linux/bootmem.h b/include/linux/bootmem.h
index 4e2bd4c95b66..0995c2de8162 100644
--- a/include/linux/bootmem.h
+++ b/include/linux/bootmem.h
@@ -46,6 +46,7 @@ extern unsigned long init_bootmem_node(pg_data_t *pgdat,
extern unsigned long init_bootmem(unsigned long addr, unsigned long memend);
extern unsigned long free_all_bootmem(void);
+extern void reset_node_managed_pages(pg_data_t *pgdat);
extern void reset_all_zones_managed_pages(void);
extern void free_bootmem_node(pg_data_t *pgdat,
diff --git a/mm/bootmem.c b/mm/bootmem.c
index 8a000cebb0d7..477be696511d 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -243,13 +243,10 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
static int reset_managed_pages_done __initdata;
-static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
+void reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- if (reset_managed_pages_done)
- return;
-
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->managed_pages = 0;
}
@@ -258,8 +255,12 @@ void __init reset_all_zones_managed_pages(void)
{
struct pglist_data *pgdat;
+ if (reset_managed_pages_done)
+ return;
+
for_each_online_pgdat(pgdat)
reset_node_managed_pages(pgdat);
+
reset_managed_pages_done = 1;
}
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 252e1dbbed86..c5f7fe199a60 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -31,6 +31,7 @@
#include <linux/stop_machine.h>
#include <linux/hugetlb.h>
#include <linux/memblock.h>
+#include <linux/bootmem.h>
#include <asm/tlbflush.h>
@@ -1096,6 +1097,14 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
build_all_zonelists(pgdat, NULL);
mutex_unlock(&zonelists_mutex);
+ /*
+ * zone->managed_pages is set to an approximate value in
+ * free_area_init_core(), which will cause
+ * /sys/device/system/node/nodeX/meminfo has wrong data.
+ * So reset it to 0 before any memory is onlined.
+ */
+ reset_node_managed_pages(pgdat);
+
return pgdat;
}
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 7c7ab32ee503..90b50468333e 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -145,12 +145,10 @@ static unsigned long __init free_low_memory_core_early(void)
static int reset_managed_pages_done __initdata;
-static inline void __init reset_node_managed_pages(pg_data_t *pgdat)
+void reset_node_managed_pages(pg_data_t *pgdat)
{
struct zone *z;
- if (reset_managed_pages_done)
- return;
for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
z->managed_pages = 0;
}
@@ -159,8 +157,12 @@ void __init reset_all_zones_managed_pages(void)
{
struct pglist_data *pgdat;
+ if (reset_managed_pages_done)
+ return;
+
for_each_online_pgdat(pgdat)
reset_node_managed_pages(pgdat);
+
reset_managed_pages_done = 1;
}