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
online_pages().

Signed-off-by: default avatarYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent cca448fe

mm/memory_hotplug.c

+12 −0
Original line number Diff line number Diff line
@@ -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);

		online_page(page);
@@ -149,5 +158,8 @@ int online_pages(unsigned long pfn, unsigned long nr_pages) 


	setup_per_zone_pages_min();



	if (need_zonelists_rebuild)

		build_all_zonelists();



	return 0;

}

mm/page_alloc.c

+21 −5
Original line number Diff line number Diff line
@@ -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;

	for_each_online_node(nid)

		build_zonelists(NODE_DATA(nid));

	return 0;

}



	for_each_online_node(i)

		build_zonelists(NODE_DATA(i));

	printk("Built %i zonelists\n", num_online_nodes());

void __meminit build_all_zonelists(void)

{

	if (system_state == SYSTEM_BOOTING) {

		__build_all_zonelists(0);

		cpuset_init_current_mems_allowed();

	} 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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