Commit 9af3c2de authored Jun 27, 2006 by Yasunori Goto Committed by Linus Torvalds Jun 27, 2006

[PATCH] pgdat allocation for new node add (call pgdat allocation)



Add node-hot-add support to add_memory().

node hotadd uses this sequence.
1. allocate pgdat.
2. refresh NODE_DATA()
3. call free_area_init_node() to initialize
4. create sysfs entry
5. add memory (old add_memory())
6. set node online
7. run kswapd for new node.
(8). update zonelist after pages are onlined. (This is already merged in -mm
   due to update phase is difference.)

Note:
  To make common function as much as possible,
  there is 2 changes from v2.
    - The old add_memory(), which is defiend by each archs,
      is renamed to arch_add_memory(). New add_memory becomes
      caller of arch dependent function as a common code.

    - This patch changes add_memory()'s interface
        From: add_memory(start, end)
        TO  : add_memory(nid, start, end).
      It was cause of similar code that finding node id from
      physical address is inside of old add_memory() on each arch.

      In addition, acpi memory hotplug driver can find node id easier.
      In v2, it must walk DSDT'S _CRS by matching physical address to
      get the handle of its memory device, then get _PXM and node id.
      Because input is just physical address.
      However, in v3, the acpi driver can use handle to get _PXM and node id
      for the new memory device. It can pass just node id to add_memory().

Fix interface of arch_add_memory() is in next patche.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 3218ae14

mm/memory_hotplug.c

+52 −0

Original line number	Diff line number	Diff line
		@@ -164,13 +164,65 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
		return 0;
		}

		static pg_data_t *hotadd_new_pgdat(int nid, u64 start)
		{
		struct pglist_data *pgdat;
		unsigned long zones_size[MAX_NR_ZONES] = {0};
		unsigned long zholes_size[MAX_NR_ZONES] = {0};
		unsigned long start_pfn = start >> PAGE_SHIFT;

		pgdat = arch_alloc_nodedata(nid);
		if (!pgdat)
		return NULL;

		arch_refresh_nodedata(nid, pgdat);

		/* we can use NODE_DATA(nid) from here */

		/* init node's zones as empty zones, we don't have any present pages.*/
		free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);

		return pgdat;
		}

		static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
		{
		arch_refresh_nodedata(nid, NULL);
		arch_free_nodedata(pgdat);
		return;
		}

		int add_memory(int nid, u64 start, u64 size)
		{
		pg_data_t *pgdat = NULL;
		int new_pgdat = 0;
		int ret;

		if (!node_online(nid)) {
		pgdat = hotadd_new_pgdat(nid, start);
		if (!pgdat)
		return -ENOMEM;
		new_pgdat = 1;
		ret = kswapd_run(nid);
		if (ret)
		goto error;
		}

		/* call arch's memory hotadd */
		ret = arch_add_memory(nid, start, size);

		if (ret < 0)
		goto error;

		/* we online node here. we have no error path from here. */
		node_set_online(nid);

		return ret;
		error:
		/* rollback pgdat allocation and others */
		if (new_pgdat)
		rollback_node_hotadd(nid, pgdat);

		return ret;
		}
		EXPORT_SYMBOL_GPL(add_memory);