Commit 6811378e authored by Yasunori Goto's avatar Yasunori Goto Committed by Linus Torvalds
Browse files

[PATCH] wait_table and zonelist initializing for memory hotadd: update zonelists

In current code, zonelist is considered to be build once, no modification.
But MemoryHotplug can add new zone/pgdat.  It must be updated.

This patch modifies build_all_zonelists().  By this, build_all_zonelist() can
reconfig pgdat's zonelists.

To update them safety, this patch use stop_machine_run().  Other cpus don't
touch among updating them by using it.

In old version (V2 of node hotadd), kernel updated them after zone
initialization.  But present_page of its new zone is still 0, because
online_page() is not called yet at this time.  Build_zonelists() checks
present_pages to find present zone.  It was too early.  So, I changed it after
Signed-off-by: default avatarYasunori Goto     <>
Signed-off-by: default avatarKAMEZAWA Hiroyuki <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent cca448fe
......@@ -127,6 +127,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
* This doesn't need a lock to do pfn_to_page().
......@@ -139,6 +140,14 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
pgdat_resize_unlock(zone->zone_pgdat, &flags);
* If this zone is not populated, then it is not in zonelist.
* This means the page allocator ignores this zone.
* So, zonelist must be updated after online.
if (!populated_zone(zone))
need_zonelists_rebuild = 1;
for (i = 0; i < nr_pages; i++) {
struct page *page = pfn_to_page(pfn + i);
......@@ -149,5 +158,8 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
if (need_zonelists_rebuild)
return 0;
......@@ -37,6 +37,7 @@
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
#include <linux/mempolicy.h>
#include <linux/stop_machine.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
......@@ -1704,14 +1705,29 @@ static void __meminit build_zonelists(pg_data_t *pgdat)
#endif /* CONFIG_NUMA */
void __init build_all_zonelists(void)
/* return values int ....just for stop_machine_run() */
static int __meminit __build_all_zonelists(void *dummy)
int i;
int nid;
return 0;
void __meminit build_all_zonelists(void)
if (system_state == SYSTEM_BOOTING) {
} else {
/* we have to stop all cpus to guaranntee there is no user
of zonelist */
stop_machine_run(__build_all_zonelists, NULL, NR_CPUS);
/* cpuset refresh routine should be here */
printk("Built %i zonelists\n", num_online_nodes());
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