[PATCH 1/7] Introduce mechanism for registering active regions of memory

From: Mel Gorman
Date: Mon Apr 24 2006 - 16:21:38 EST


This patch defines the structure to represent an active range of page
frames within a node in an architecture independent manner. Architectures
are expected to register active ranges of PFNs using add_active_range(nid,
start_pfn, end_pfn) and call free_area_init_nodes() passing the PFNs of
the end of each zone.


include/linux/mm.h | 19 ++
include/linux/mmzone.h | 15 +
mm/page_alloc.c | 395 +++++++++++++++++++++++++++++++++++++++++---
3 files changed, 404 insertions(+), 25 deletions(-)

Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.17-rc2-clean/include/linux/mm.h linux-2.6.17-rc2-101-add_free_area_init_nodes/include/linux/mm.h
--- linux-2.6.17-rc2-clean/include/linux/mm.h 2006-04-19 04:00:49.000000000 +0100
+++ linux-2.6.17-rc2-101-add_free_area_init_nodes/include/linux/mm.h 2006-04-24 15:49:25.000000000 +0100
@@ -866,6 +866,25 @@ extern void free_area_init(unsigned long
extern void free_area_init_node(int nid, pg_data_t *pgdat,
unsigned long * zones_size, unsigned long zone_start_pfn,
unsigned long *zholes_size);
+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+extern void free_area_init_nodes(unsigned long max_dma_pfn,
+ unsigned long max_dma32_pfn,
+ unsigned long max_low_pfn,
+ unsigned long max_high_pfn);
+extern void add_active_range(unsigned int nid, unsigned long start_pfn,
+ unsigned long end_pfn);
+extern void remove_all_active_ranges(void);
+extern void get_pfn_range_for_nid(unsigned int nid,
+ unsigned long *start_pfn, unsigned long *end_pfn);
+extern unsigned long find_min_pfn_with_active_regions(void);
+extern unsigned long find_max_pfn_with_active_regions(void);
+extern int early_pfn_to_nid(unsigned long pfn);
+extern void free_bootmem_with_active_regions(int nid,
+ unsigned long max_low_pfn);
+extern void sparse_memory_present_with_active_regions(int nid);
+extern unsigned long absent_pages_in_range(unsigned long start_pfn,
+ unsigned long end_pfn);
+#endif
extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long);
extern void setup_per_zone_pages_min(void);
extern void mem_init(void);
diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.17-rc2-clean/include/linux/mmzone.h linux-2.6.17-rc2-101-add_free_area_init_nodes/include/linux/mmzone.h
--- linux-2.6.17-rc2-clean/include/linux/mmzone.h 2006-04-19 04:00:49.000000000 +0100
+++ linux-2.6.17-rc2-101-add_free_area_init_nodes/include/linux/mmzone.h 2006-04-24 15:49:25.000000000 +0100
@@ -271,6 +271,18 @@ struct zonelist {
struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited
};

+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+/*
+ * This represents an active range of physical memory. Architectures register
+ * a pfn range using add_active_range() and later initialise the nodes and
+ * free list with free_area_init_nodes()
+ */
+struct node_active_region {
+ unsigned long start_pfn;
+ unsigned long end_pfn;
+ int nid;
+};
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */

/*
* The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
@@ -465,7 +477,8 @@ extern struct zone *next_zone(struct zon

#endif

-#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+#if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
+ !defined(CONFIG_ARCH_POPULATES_NODE_MAP)
#define early_pfn_to_nid(nid) (0UL)
#endif

diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.17-rc2-clean/mm/page_alloc.c linux-2.6.17-rc2-101-add_free_area_init_nodes/mm/page_alloc.c
--- linux-2.6.17-rc2-clean/mm/page_alloc.c 2006-04-19 04:00:49.000000000 +0100
+++ linux-2.6.17-rc2-101-add_free_area_init_nodes/mm/page_alloc.c 2006-04-24 15:49:25.000000000 +0100
@@ -37,6 +37,8 @@
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
#include <linux/mempolicy.h>
+#include <linux/sort.h>
+#include <linux/pfn.h>

#include <asm/tlbflush.h>
#include "internal.h"
@@ -85,6 +87,18 @@ int min_free_kbytes = 1024;
unsigned long __initdata nr_kernel_pages;
unsigned long __initdata nr_all_pages;

+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+ #ifdef CONFIG_MAX_ACTIVE_REGIONS
+ #define MAX_ACTIVE_REGIONS CONFIG_MAX_ACTIVE_REGIONS
+ #else
+ #define MAX_ACTIVE_REGIONS (MAX_NR_ZONES * MAX_NUMNODES + 1)
+ #endif
+
+ struct node_active_region __initdata early_node_map[MAX_ACTIVE_REGIONS];
+ unsigned long __initdata arch_zone_lowest_possible_pfn[MAX_NR_ZONES];
+ unsigned long __initdata arch_zone_highest_possible_pfn[MAX_NR_ZONES];
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
+
#ifdef CONFIG_DEBUG_VM
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
@@ -1749,25 +1763,6 @@ static inline unsigned long wait_table_b

#define LONG_ALIGN(x) (((x)+(sizeof(long))-1)&~((sizeof(long))-1))

-static void __init calculate_zone_totalpages(struct pglist_data *pgdat,
- unsigned long *zones_size, unsigned long *zholes_size)
-{
- unsigned long realtotalpages, totalpages = 0;
- int i;
-
- for (i = 0; i < MAX_NR_ZONES; i++)
- totalpages += zones_size[i];
- pgdat->node_spanned_pages = totalpages;
-
- realtotalpages = totalpages;
- if (zholes_size)
- for (i = 0; i < MAX_NR_ZONES; i++)
- realtotalpages -= zholes_size[i];
- pgdat->node_present_pages = realtotalpages;
- printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
-}
-
-
/*
* Initially all pages are reserved - free ones are freed
* up by free_all_bootmem() once the early boot process is
@@ -2054,6 +2049,221 @@ static __meminit void init_currently_emp
zone_init_free_lists(pgdat, zone, zone->spanned_pages);
}

+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+/* Note: nid == MAX_NUMNODES returns first region */
+static int __init first_active_region_index_in_nid(int nid)
+{
+ int i;
+ for (i = 0; early_node_map[i].end_pfn; i++) {
+ if (nid == MAX_NUMNODES || early_node_map[i].nid == nid)
+ return i;
+ }
+
+ return MAX_ACTIVE_REGIONS;
+}
+
+/* Note: nid == MAX_NUMNODES returns next region */
+static int __init next_active_region_index_in_nid(unsigned int index, int nid)
+{
+ for (index = index + 1; early_node_map[index].end_pfn; index++) {
+ if (nid == MAX_NUMNODES || early_node_map[index].nid == nid)
+ return index;
+ }
+
+ return MAX_ACTIVE_REGIONS;
+}
+
+#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
+int __init early_pfn_to_nid(unsigned long pfn)
+{
+ int i;
+
+ for (i = 0; early_node_map[i].end_pfn; i++) {
+ unsigned long start_pfn = early_node_map[i].start_pfn;
+ unsigned long end_pfn = early_node_map[i].end_pfn;
+
+ if ((start_pfn <= pfn) && (pfn < end_pfn))
+ return early_node_map[i].nid;
+ }
+
+ return -1;
+}
+#endif /* CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID */
+
+#define for_each_active_range_index_in_nid(i, nid) \
+ for (i = first_active_region_index_in_nid(nid); \
+ i != MAX_ACTIVE_REGIONS; \
+ i = next_active_region_index_in_nid(i, nid))
+
+void __init free_bootmem_with_active_regions(int nid,
+ unsigned long max_low_pfn)
+{
+ unsigned int i;
+ for_each_active_range_index_in_nid(i, nid) {
+ unsigned long size_pages = 0;
+ unsigned long end_pfn = early_node_map[i].end_pfn;
+ if (early_node_map[i].start_pfn >= max_low_pfn)
+ continue;
+
+ if (end_pfn > max_low_pfn)
+ end_pfn = max_low_pfn;
+
+ size_pages = end_pfn - early_node_map[i].start_pfn;
+ free_bootmem_node(NODE_DATA(early_node_map[i].nid),
+ PFN_PHYS(early_node_map[i].start_pfn),
+ PFN_PHYS(size_pages));
+ }
+}
+
+void __init sparse_memory_present_with_active_regions(int nid)
+{
+ unsigned int i;
+ for_each_active_range_index_in_nid(i, nid)
+ memory_present(early_node_map[i].nid,
+ early_node_map[i].start_pfn,
+ early_node_map[i].end_pfn);
+}
+
+void __init get_pfn_range_for_nid(unsigned int nid,
+ unsigned long *start_pfn, unsigned long *end_pfn)
+{
+ unsigned int i;
+ *start_pfn = -1UL;
+ *end_pfn = 0;
+
+ for_each_active_range_index_in_nid(i, nid) {
+ if (early_node_map[i].start_pfn < *start_pfn)
+ *start_pfn = early_node_map[i].start_pfn;
+
+ if (early_node_map[i].end_pfn > *end_pfn)
+ *end_pfn = early_node_map[i].end_pfn;
+ }
+
+ if (*start_pfn == -1UL) {
+ printk(KERN_WARNING "Node %u active with no memory\n", nid);
+ *start_pfn = 0;
+ }
+}
+
+unsigned long __init zone_present_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *ignored)
+{
+ unsigned long node_start_pfn, node_end_pfn;
+ unsigned long zone_start_pfn, zone_end_pfn;
+
+ /* Get the start and end of the node and zone */
+ get_pfn_range_for_nid(nid, &node_start_pfn, &node_end_pfn);
+ zone_start_pfn = arch_zone_lowest_possible_pfn[zone_type];
+ zone_end_pfn = arch_zone_highest_possible_pfn[zone_type];
+
+ /* Check that this node has pages within the zone's required range */
+ if (zone_end_pfn < node_start_pfn || zone_start_pfn > node_end_pfn)
+ return 0;
+
+ /* Move the zone boundaries inside the node if necessary */
+ if (zone_end_pfn > node_end_pfn)
+ zone_end_pfn = node_end_pfn;
+ if (zone_start_pfn < node_start_pfn)
+ zone_start_pfn = node_start_pfn;
+
+ /* Return the spanned pages */
+ return zone_end_pfn - zone_start_pfn;
+}
+
+unsigned long __init __absent_pages_in_range(int nid,
+ unsigned long range_start_pfn,
+ unsigned long range_end_pfn)
+{
+ int i = 0;
+ unsigned long prev_end_pfn = 0, hole_pages = 0;
+ unsigned long start_pfn;
+
+ /* Find the end_pfn of the first active range of pfns in the node */
+ i = first_active_region_index_in_nid(nid);
+ prev_end_pfn = early_node_map[i].start_pfn;
+
+ /* Find all holes for the zone within the node */
+ for (; i != MAX_ACTIVE_REGIONS;
+ i = next_active_region_index_in_nid(i, nid)) {
+
+ /* No need to continue if prev_end_pfn is outside the zone */
+ if (prev_end_pfn >= range_end_pfn)
+ break;
+
+ /* Make sure the end of the zone is not within the hole */
+ start_pfn = early_node_map[i].start_pfn;
+ if (start_pfn > range_end_pfn)
+ start_pfn = range_end_pfn;
+ if (prev_end_pfn < range_start_pfn)
+ prev_end_pfn = range_start_pfn;
+
+ /* Update the hole size cound and move on */
+ if (start_pfn > range_start_pfn) {
+ BUG_ON(prev_end_pfn > start_pfn);
+ hole_pages += start_pfn - prev_end_pfn;
+ }
+ prev_end_pfn = early_node_map[i].end_pfn;
+ }
+
+ return hole_pages;
+}
+
+unsigned long __init absent_pages_in_range(unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ return __absent_pages_in_range(MAX_NUMNODES, start_pfn, end_pfn);
+}
+
+unsigned long __init zone_absent_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *ignored)
+{
+ return __absent_pages_in_range(nid,
+ arch_zone_lowest_possible_pfn[zone_type],
+ arch_zone_highest_possible_pfn[zone_type]);
+}
+#else
+static inline unsigned long zone_present_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *zones_size)
+{
+ return zones_size[zone_type];
+}
+
+static inline unsigned long zone_absent_pages_in_node(int nid,
+ unsigned long zone_type,
+ unsigned long *zholes_size)
+{
+ if (!zholes_size)
+ return 0;
+
+ return zholes_size[zone_type];
+}
+#endif
+
+static void __init calculate_node_totalpages(struct pglist_data *pgdat,
+ unsigned long *zones_size, unsigned long *zholes_size)
+{
+ unsigned long realtotalpages, totalpages = 0;
+ int i;
+
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ totalpages += zone_present_pages_in_node(pgdat->node_id, i,
+ zones_size);
+ }
+ pgdat->node_spanned_pages = totalpages;
+
+ realtotalpages = totalpages;
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ realtotalpages -=
+ zone_absent_pages_in_node(pgdat->node_id, i, zholes_size);
+ }
+ pgdat->node_present_pages = realtotalpages;
+ printk(KERN_DEBUG "On node %d totalpages: %lu\n", pgdat->node_id,
+ realtotalpages);
+}
+
/*
* Set up the zone data structures:
* - mark all pages reserved
@@ -2076,10 +2286,9 @@ static void __init free_area_init_core(s
struct zone *zone = pgdat->node_zones + j;
unsigned long size, realsize;

- realsize = size = zones_size[j];
- if (zholes_size)
- realsize -= zholes_size[j];
-
+ size = zone_present_pages_in_node(nid, j, zones_size);
+ realsize = size - zone_absent_pages_in_node(nid, j,
+ zholes_size);
if (j < ZONE_HIGHMEM)
nr_kernel_pages += realsize;
nr_all_pages += realsize;
@@ -2146,13 +2355,151 @@ void __init free_area_init_node(int nid,
{
pgdat->node_id = nid;
pgdat->node_start_pfn = node_start_pfn;
- calculate_zone_totalpages(pgdat, zones_size, zholes_size);
+ calculate_node_totalpages(pgdat, zones_size, zholes_size);

alloc_node_mem_map(pgdat);

free_area_init_core(pgdat, zones_size, zholes_size);
}

+#ifdef CONFIG_ARCH_POPULATES_NODE_MAP
+void __init add_active_range(unsigned int nid, unsigned long start_pfn,
+ unsigned long end_pfn)
+{
+ unsigned int i;
+
+ /* Merge with existing active regions if possible */
+ for (i = 0; early_node_map[i].end_pfn; i++) {
+ if (early_node_map[i].nid != nid)
+ continue;
+
+ /* Skip if an existing region covers this new one */
+ if (start_pfn >= early_node_map[i].start_pfn &&
+ end_pfn <= early_node_map[i].end_pfn)
+ return;
+
+ /* Merge forward if suitable */
+ if (start_pfn <= early_node_map[i].end_pfn &&
+ end_pfn > early_node_map[i].end_pfn) {
+ early_node_map[i].end_pfn = end_pfn;
+ return;
+ }
+
+ /* Merge backward if suitable */
+ if (start_pfn < early_node_map[i].end_pfn &&
+ end_pfn >= early_node_map[i].start_pfn) {
+ early_node_map[i].start_pfn = start_pfn;
+ return;
+ }
+ }
+
+ /* Leave last entry NULL, we use range.end_pfn to terminate the walk */
+ if (i >= MAX_ACTIVE_REGIONS - 1) {
+ printk(KERN_ERR "Too many memory regions, truncating\n");
+ return;
+ }
+
+ early_node_map[i].nid = nid;
+ early_node_map[i].start_pfn = start_pfn;
+ early_node_map[i].end_pfn = end_pfn;
+}
+
+void __init remove_all_active_ranges()
+{
+ memset(early_node_map, 0, sizeof(early_node_map));
+}
+
+/* Compare two active node_active_regions */
+static int __init cmp_node_active_region(const void *a, const void *b)
+{
+ struct node_active_region *arange = (struct node_active_region *)a;
+ struct node_active_region *brange = (struct node_active_region *)b;
+
+ /* Done this way to avoid overflows */
+ if (arange->start_pfn > brange->start_pfn)
+ return 1;
+ if (arange->start_pfn < brange->start_pfn)
+ return -1;
+
+ return 0;
+}
+
+/* sort the node_map by start_pfn */
+static void __init sort_node_map(void)
+{
+ size_t num = 0;
+ while (early_node_map[num].end_pfn)
+ num++;
+
+ sort(early_node_map, num, sizeof(struct node_active_region),
+ cmp_node_active_region, NULL);
+}
+
+/* Find the lowest pfn for a node. This depends on a sorted early_node_map */
+unsigned long __init find_min_pfn_for_node(unsigned long nid)
+{
+ int i;
+
+ /* Assuming a sorted map, the first range found has the starting pfn */
+ for_each_active_range_index_in_nid(i, nid)
+ return early_node_map[i].start_pfn;
+
+ /* nid does not exist in early_node_map */
+ printk(KERN_WARNING "Could not find start_pfn for node %lu\n", nid);
+ return 0;
+}
+
+unsigned long __init find_min_pfn_with_active_regions(void)
+{
+ return find_min_pfn_for_node(MAX_NUMNODES);
+}
+
+unsigned long __init find_max_pfn_with_active_regions(void)
+{
+ int i;
+ unsigned long max_pfn = 0;
+
+ for (i = 0; early_node_map[i].end_pfn; i++)
+ max_pfn = max(max_pfn, early_node_map[i].end_pfn);
+
+ return max_pfn;
+}
+
+void __init free_area_init_nodes(unsigned long arch_max_dma_pfn,
+ unsigned long arch_max_dma32_pfn,
+ unsigned long arch_max_low_pfn,
+ unsigned long arch_max_high_pfn)
+{
+ unsigned long nid;
+ int zone_index;
+
+ /* Record where the zone boundaries are */
+ memset(arch_zone_lowest_possible_pfn, 0,
+ sizeof(arch_zone_lowest_possible_pfn));
+ memset(arch_zone_highest_possible_pfn, 0,
+ sizeof(arch_zone_highest_possible_pfn));
+ arch_zone_lowest_possible_pfn[ZONE_DMA] =
+ find_min_pfn_with_active_regions();
+ arch_zone_highest_possible_pfn[ZONE_DMA] = arch_max_dma_pfn;
+ arch_zone_highest_possible_pfn[ZONE_DMA32] = arch_max_dma32_pfn;
+ arch_zone_highest_possible_pfn[ZONE_NORMAL] = arch_max_low_pfn;
+ arch_zone_highest_possible_pfn[ZONE_HIGHMEM] = arch_max_high_pfn;
+ for (zone_index = 1; zone_index < MAX_NR_ZONES; zone_index++) {
+ arch_zone_lowest_possible_pfn[zone_index] =
+ arch_zone_highest_possible_pfn[zone_index-1];
+ }
+
+ /* Regions in the early_node_map can be in any order */
+ sort_node_map();
+
+ for_each_online_node(nid) {
+ pg_data_t *pgdat = NODE_DATA(nid);
+ free_area_init_node(nid, pgdat, NULL,
+ find_min_pfn_for_node(nid), NULL);
+ }
+}
+#endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
+
#ifndef CONFIG_NEED_MULTIPLE_NODES
static bootmem_data_t contig_bootmem_data;
struct pglist_data contig_page_data = { .bdata = &contig_bootmem_data };
-
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