At 12/26/2012 11:55 AM, Kamezawa Hiroyuki Wrote:
> (2012/12/24 21:09), Tang Chen wrote:
>> From: Wen Congyang <wency@xxxxxxxxxxxxxx>
>>
>> We call hotadd_new_pgdat() to allocate memory to store node_data. So we
>> should free it when removing a node.
>>
>> Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
>
> I'm sorry but is it safe to remove pgdat ? All zone cache and zonelists are
> properly cleared/rebuilded in synchronous way ? and No threads are visinting
> zone in vmscan.c ?
We have rebuilt zonelists when a zone has no memory after offlining some pages.
Thanks
Wen Congyang
>
> Thanks,
> -Kame
>
>> ---
>> mm/memory_hotplug.c | 20 +++++++++++++++++++-
>> 1 files changed, 19 insertions(+), 1 deletions(-)
>>
>> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
>> index f8a1d2f..447fa24 100644
>> --- a/mm/memory_hotplug.c
>> +++ b/mm/memory_hotplug.c
>> @@ -1680,9 +1680,12 @@ 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);
>> @@ -1709,6 +1712,21 @@ 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)
>>
>
>
>
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