[PATCH] x86: shrink pages should check all v2

From: Yinghai Lu
Date: Sun Jun 08 2008 - 22:39:04 EST



we are uing register_e820_active_regions instead of add_active_range directly.
so end_pfn could be different between the value in early_node_map to node_end_pfn.

need to make shrink_active_range more smart.

shrink_active_range is only used x86 32 bit, or need to move back in some file
in arch/x86?

v2: use memcpy instead

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

Index: linux-2.6/include/linux/mm.h
===================================================================
--- linux-2.6.orig/include/linux/mm.h
+++ linux-2.6/include/linux/mm.h
@@ -997,8 +997,7 @@ extern void free_area_init_node(int nid,
extern void free_area_init_nodes(unsigned long *max_zone_pfn);
extern void add_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn);
-extern void shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
- unsigned long new_end_pfn);
+extern void shrink_active_range(unsigned int nid, unsigned long new_end_pfn);
extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn);
extern void remove_all_active_ranges(void);
Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c
+++ linux-2.6/mm/page_alloc.c
@@ -3592,25 +3592,49 @@ void __init add_active_range(unsigned in
/**
* shrink_active_range - Shrink an existing registered range of PFNs
* @nid: The node id the range is on that should be shrunk
- * @old_end_pfn: The old end PFN of the range
* @new_end_pfn: The new PFN of the range
*
* i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
- * The map is kept at the end physical page range that has already been
- * registered with add_active_range(). This function allows an arch to shrink
- * an existing registered range.
+ * The map is kept near the end physical page range that has already been
+ * registered. This function allows an arch to shrink an existing registered
+ * range.
*/
-void __init shrink_active_range(unsigned int nid, unsigned long old_end_pfn,
- unsigned long new_end_pfn)
+void __init shrink_active_range(unsigned int nid, unsigned long new_end_pfn)
{
- int i;
+ int i, j;
+ int removed = 0;

/* Find the old active region end and shrink */
- for_each_active_range_index_in_nid(i, nid)
- if (early_node_map[i].end_pfn == old_end_pfn) {
+ for_each_active_range_index_in_nid(i, nid) {
+ if (early_node_map[i].start_pfn >= new_end_pfn) {
+ /* clear it */
+ early_node_map[i].end_pfn = 0;
+ removed = 1;
+ continue;
+ }
+ if (early_node_map[i].end_pfn > new_end_pfn) {
early_node_map[i].end_pfn = new_end_pfn;
- break;
+ continue;
}
+ }
+
+ if (!removed)
+ return;
+
+ /* remove the blank ones */
+ for (i = nr_nodemap_entries - 1; i > 0; i--) {
+ if (early_node_map[i].nid != nid)
+ continue;
+ if (early_node_map[i].end_pfn)
+ continue;
+ /* we found it, get rid of it */
+ for (j = i; j < nr_nodemap_entries - 1; j++)
+ memcpy(&early_node_map[j], &early_node_map[j+1],
+ sizeof(early_node_map[j]));
+ j = nr_nodemap_entries - 1;
+ memset(&early_node_map[j], 0, sizeof(early_node_map[j]));
+ nr_nodemap_entries--;
+ }
}

/**
Index: linux-2.6/arch/x86/mm/discontig_32.c
===================================================================
--- linux-2.6.orig/arch/x86/mm/discontig_32.c
+++ linux-2.6/arch/x86/mm/discontig_32.c
@@ -279,7 +279,7 @@ static unsigned long calculate_numa_rema

node_end_pfn[nid] -= size;
node_remap_start_pfn[nid] = node_end_pfn[nid];
- shrink_active_range(nid, old_end_pfn, node_end_pfn[nid]);
+ shrink_active_range(nid, node_end_pfn[nid]);
}
printk("Reserving total of %ld pages for numa KVA remap\n",
reserve_pages);
--
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