Re: [PATCH v3 3/5] page_alloc: Introduce zone_movable_limit[] to keep movable limit for nodes

On 2012-12-11 19:28, Simon Jeons wrote:

On Tue, 2012-12-11 at 11:32 +0800, Tang Chen wrote:

quoted

On 12/11/2012 11:07 AM, Jianguo Wu wrote:

quoted

On 2012/12/11 10:33, Tang Chen wrote:

quoted

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.

What's the difference between zone_movable_limit[nid] and
zone_movable_pfn[nid]?

zone_movable_limit[] is a temporary storage for zone_moveable_pfn[].
It's used to handle a special case if user specifies both movablecore_map
and movablecore/kernelcore on the kernel command line. 

quoted

quoted

quoted

Signed-off-by: Tang Chen<redacted>
Signed-off-by: Jiang Liu<redacted>
Reviewed-by: Wen Congyang<redacted>
Reviewed-by: Lai Jiangshan<redacted>
Tested-by: Lin Feng<redacted>
---
  mm/page_alloc.c |   77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
  1 files changed, 77 insertions(+), 0 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1c91d16..4853619 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;

@@ -4340,6 +4341,77 @@ 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;
+
+#ifdef CONFIG_ZONE_DMA
+		/* Skip DMA memory. */
+		if (start_pfn<  arch_zone_highest_possible_pfn[ZONE_DMA])
+			start_pfn = arch_zone_highest_possible_pfn[ZONE_DMA];
+#endif
+
+#ifdef CONFIG_ZONE_DMA32
+		/* Skip DMA32 memory. */
+		if (start_pfn<  arch_zone_highest_possible_pfn[ZONE_DMA32])
+			start_pfn = arch_zone_highest_possible_pfn[ZONE_DMA32];
+#endif
+
+#ifdef CONFIG_HIGHMEM
+		/* Skip lowmem if ZONE_MOVABLE is highmem. */
+		if (zone_movable_is_highmem()&&

Hi Tang,

I think zone_movable_is_highmem() is not work correctly here.
	sanitize_zone_movable_limit
		zone_movable_is_highmem<--using movable_zone here
	find_zone_movable_pfns_for_nodes
		find_usable_zone_for_movable<--movable_zone is specified here

I think Jiang Liu's patch works fine for highmem, please refer to:
http://marc.info/?l=linux-mm&m=135476085816087&w=2

Hi Wu,

Yes, I forgot movable_zone think. Thanks for reminding me. :)

But Liu's patch you just mentioned, I didn't use it because I
don't think we should skip kernelcore when movablecore_map is specified.
If these 2 options are not conflict, we should satisfy them both. :)

Of course, I also think Liu's suggestion is wonderful. But I think we
need more discussion on it. :)

I'll fix it soon.
Thanks. :)

quoted

Thanks,
Jianguo Wu

quoted

+		    start_pfn<  arch_zone_lowest_possible_pfn[ZONE_HIGHMEM])
+			start_pfn = arch_zone_lowest_possible_pfn[ZONE_HIGHMEM];
+#endif
+
+		if (start_pfn>= end_pfn)
+			continue;
+
+		while (map_pos<  movablecore_map.nr_map) {
+			if (end_pfn<= movablecore_map.map[map_pos].start_pfn)
+				break;
+
+			if (start_pfn>= movablecore_map.map[map_pos].end_pfn) {
+				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_pfn);
+
+			break;
+		}
+	}
+}
+
  #else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
  static inline unsigned long __meminit zone_spanned_pages_in_node(int nid,
  					unsigned long zone_type,

@@ -4358,6 +4430,10 @@ 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,

@@ -4923,6 +4999,7 @@ 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 */

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

.

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>