Re: [PATCH v2 3/5] page_alloc: Introduce zone_movable_limit[] to keep movable limit for nodes

[Tang Chen <tangchen@cn.fujitsu.com>]

On 12/05/2012 11:46 PM, Jiang Liu wrote:
> On 11/23/2012 06:44 PM, Tang Chen wrote:
>> This patch introduces a new array zone_movable_limit[] to store the
>> ZONE_MOVABLE limit from movablecore_map boot option for all nodes.
>> The function sanitize_zone_movable_limit() will find out to which
>> node the ranges in movable_map.map[] belongs, and calculates the
>> low boundary of ZONE_MOVABLE for each node.
>>
>> Signed-off-by: Tang Chen<tangchen@cn.fujitsu.com>
>> Reviewed-by: Wen Congyang<wency@cn.fujitsu.com>
>> Reviewed-by: Lai Jiangshan<laijs@cn.fujitsu.com>
>> Tested-by: Lin Feng<linfeng@cn.fujitsu.com>
>> ---
>>   mm/page_alloc.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 files changed, 55 insertions(+), 0 deletions(-)
>>
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index fb5cf12..f23d76a 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -206,6 +206,7 @@ static unsigned long __meminitdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
>>   static unsigned long __initdata required_kernelcore;
>>   static unsigned long __initdata required_movablecore;
>>   static unsigned long __meminitdata zone_movable_pfn[MAX_NUMNODES];
>> +static unsigned long __meminitdata zone_movable_limit[MAX_NUMNODES];
>>
>>   /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
>>   int movable_zone;
>> @@ -4323,6 +4324,55 @@ static unsigned long __meminit zone_absent_pages_in_node(int nid,
>>   	return __absent_pages_in_range(nid, zone_start_pfn, zone_end_pfn);
>>   }
>>
>> +/**
>> + * sanitize_zone_movable_limit - Sanitize the zone_movable_limit array.
>> + *
>> + * zone_movable_limit is initialized as 0. This function will try to get
>> + * the first ZONE_MOVABLE pfn of each node from movablecore_map, and
>> + * assigne them to zone_movable_limit.
>> + * zone_movable_limit[nid] == 0 means no limit for the node.
>> + *
>> + * Note: Each range is represented as [start_pfn, end_pfn)
>> + */
>> +static void __meminit sanitize_zone_movable_limit(void)
>> +{
>> +	int map_pos = 0, i, nid;
>> +	unsigned long start_pfn, end_pfn;
>> +
>> +	if (!movablecore_map.nr_map)
>> +		return;
>> +
>> +	/* Iterate all ranges from minimum to maximum */
>> +	for_each_mem_pfn_range(i, MAX_NUMNODES,&start_pfn,&end_pfn,&nid) {
>> +		/*
>> +		 * If we have found lowest pfn of ZONE_MOVABLE of the node
>> +		 * specified by user, just go on to check next range.
>> +		 */
>> +		if (zone_movable_limit[nid])
>> +			continue;
> Need special handling of low memory here on systems with highmem, otherwise
> it will cause us to configure both lowmem and highmem as movable_zone.

Hi Liu,

Yes, and also the DMA address checking you mentioned before.

Thanks. :)

>
>> +
>> +		while (map_pos<  movablecore_map.nr_map) {
>> +			if (end_pfn<= movablecore_map.map[map_pos].start)
>> +				break;
>> +
>> +			if (start_pfn>= movablecore_map.map[map_pos].end) {
>> +				map_pos++;
>> +				continue;
>> +			}
>> +
>> +			/*
>> +			 * The start_pfn of ZONE_MOVABLE is either the minimum
>> +			 * pfn specified by movablecore_map, or 0, which means
>> +			 * the node has no ZONE_MOVABLE.
>> +			 */
>> +			zone_movable_limit[nid] = max(start_pfn,
>> +					movablecore_map.map[map_pos].start);
>> +
>> +			break;
>> +		}
>> +	}
>> +}
>> +
>>   #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>>   static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
>>   					unsigned long zone_type,
>> @@ -4341,6 +4391,10 @@ static inline unsigned long __meminit zone_absent_pages_in_node(int nid,
>>   	return zholes_size[zone_type];
>>   }
>>
>> +static void __meminit sanitize_zone_movable_limit(void)
>> +{
>> +}
>> +
>>   #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
>>
>>   static void __meminit calculate_node_totalpages(struct pglist_data *pgdat,
>> @@ -4906,6 +4960,7 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
>>
>>   	/* Find the PFNs that ZONE_MOVABLE begins at in each node */
>>   	memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));
>> +	sanitize_zone_movable_limit();
>>   	find_zone_movable_pfns_for_nodes();
>>
>>   	/* Print out the zone ranges */
>>
>
>