Re: [Patch v4 12/12] memory-hotplug: free node_data when a node is offlined

Tang Chen
2012-12-04T10:10:13Z

On 11/27/2012 06:00 PM, Wen Congyang wrote:
> We call hotadd_new_pgdat() to allocate memory to store node_data. So we
> should free it when removing a node.
>
> CC: David Rientjes<rientjes@google.com>
> CC: Jiang Liu<liuj97@gmail.com>
> CC: Len Brown<len.brown@intel.com>
> CC: Benjamin Herrenschmidt<benh@kernel.crashing.org>
> CC: Paul Mackerras<paulus@samba.org>
> CC: Christoph Lameter<cl@linux.com>
> Cc: Minchan Kim<minchan.kim@gmail.com>
> CC: Andrew Morton<akpm@linux-foundation.org>
> CC: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
> CC: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>

Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>

> ---
> mm/memory_hotplug.c | 20 +++++++++++++++++++-
> 1 file changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 449663e..d1451ab 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1309,9 +1309,12 @@ static int check_cpu_on_node(void *data)
> /* offline the node if all memory sections of this node are removed */
> static void try_offline_node(int nid)
> {
> + pg_data_t *pgdat = NODE_DATA(nid);
> unsigned long start_pfn = NODE_DATA(nid)->node_start_pfn;
> - unsigned long end_pfn = start_pfn + NODE_DATA(nid)->node_spanned_pages;
> + unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages;
> unsigned long pfn;
> + struct page *pgdat_page = virt_to_page(pgdat);
> + int i;
>
> for (pfn = start_pfn; pfn< end_pfn; pfn += PAGES_PER_SECTION) {
> unsigned long section_nr = pfn_to_section_nr(pfn);
> @@ -1338,6 +1341,21 @@ static void try_offline_node(int nid)
> */
> node_set_offline(nid);
> unregister_one_node(nid);
> +
> + if (!PageSlab(pgdat_page)&& !PageCompound(pgdat_page))
> + /* node data is allocated from boot memory */
> + return;
> +
> + /* free waittable in each zone */
> + for (i = 0; i< MAX_NR_ZONES; i++) {
> + struct zone *zone = pgdat->node_zones + i;
> +
> + if (zone->wait_table)
> + vfree(zone->wait_table);
> + }
> +
> + arch_refresh_nodedata(nid, NULL);
> + arch_free_nodedata(pgdat);
> }
>
> int __ref remove_memory(int nid, u64 start, u64 size)