This patch adds a "usemap" to the allocator. Each bit in the usemap indicates
whether a block of 2^(MAX_ORDER-1) pages are being used for kernel or
easily-reclaimed allocations. This enumerates two types of allocations;
RCLM_NORLM: These are kernel allocations that cannot be reclaimed
on demand.
RCLM_EASY: These are pages allocated with __GFP_EASYRCLM flag set. They are
considered to be user and other easily reclaimed pages such
as buffers
gfpflags_to_rclmtype() converts gfp_flags to their corresponding RCLM_TYPE.
Signed-off-by: Mel Gorman <[email protected]>
diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.14-mm2-001_antidefrag_flags/include/linux/mmzone.h linux-2.6.14-mm2-002_usemap/include/linux/mmzone.h
--- linux-2.6.14-mm2-001_antidefrag_flags/include/linux/mmzone.h 2005-11-13 21:22:26.000000000 +0000
+++ linux-2.6.14-mm2-002_usemap/include/linux/mmzone.h 2005-11-15 12:42:15.000000000 +0000
@@ -21,6 +21,11 @@
#else
#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
#endif
+#define PAGES_PER_MAXORDER (1 << (MAX_ORDER-1))
+
+#define RCLM_NORCLM 0
+#define RCLM_EASY 1
+#define RCLM_TYPES 2
struct free_area {
struct list_head free_list;
@@ -147,6 +152,12 @@ struct zone {
#endif
struct free_area free_area[MAX_ORDER];
+#ifndef CONFIG_SPARSEMEM
+ /*
+ * The map tracks what each 2^MAX_ORDER-1 sized block is being used for.
+ */
+ unsigned long *free_area_usemap;
+#endif
ZONE_PADDING(_pad1_)
@@ -502,9 +513,14 @@ extern struct pglist_data contig_page_da
#define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
#define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
+#define FREE_AREA_BITS 64
+
#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_ORDER exceeds SECTION_SIZE
#endif
+#if ((SECTION_SIZE_BITS - MAX_ORDER)) > FREE_AREA_BITS
+#error free_area_usemap is not big enough
+#endif
struct page;
struct mem_section {
@@ -517,6 +533,7 @@ struct mem_section {
* before using it wrong.
*/
unsigned long section_mem_map;
+ DECLARE_BITMAP(free_area_usemap, FREE_AREA_BITS);
};
#ifdef CONFIG_SPARSEMEM_EXTREME
@@ -585,6 +602,18 @@ static inline struct mem_section *__pfn_
return __nr_to_section(pfn_to_section_nr(pfn));
}
+static inline unsigned long *pfn_to_usemap(struct zone *zone,
+ unsigned long pfn)
+{
+ return &__pfn_to_section(pfn)->free_area_usemap[0];
+}
+
+static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
+{
+ pfn &= (PAGES_PER_SECTION-1);
+ return (pfn >> (MAX_ORDER-1));
+}
+
#define pfn_to_page(pfn) \
({ \
unsigned long __pfn = (pfn); \
@@ -622,6 +651,17 @@ void sparse_init(void);
#else
#define sparse_init() do {} while (0)
#define sparse_index_init(_sec, _nid) do {} while (0)
+static inline unsigned long *pfn_to_usemap(struct zone *zone,
+ unsigned long pfn)
+{
+ return zone->free_area_usemap;
+}
+
+static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
+{
+ pfn = pfn - zone->zone_start_pfn;
+ return (pfn >> (MAX_ORDER-1));
+}
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_NODES_SPAN_OTHER_NODES
diff -rup -X /usr/src/patchset-0.5/bin//dontdiff linux-2.6.14-mm2-001_antidefrag_flags/mm/page_alloc.c linux-2.6.14-mm2-002_usemap/mm/page_alloc.c
--- linux-2.6.14-mm2-001_antidefrag_flags/mm/page_alloc.c 2005-11-13 21:22:26.000000000 +0000
+++ linux-2.6.14-mm2-002_usemap/mm/page_alloc.c 2005-11-15 12:42:15.000000000 +0000
@@ -68,6 +68,19 @@ int sysctl_lowmem_reserve_ratio[MAX_NR_Z
EXPORT_SYMBOL(totalram_pages);
+static inline int get_pageblock_type(struct zone *zone, struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+ return !!test_bit(pfn_to_bitidx(zone, pfn),
+ pfn_to_usemap(zone, pfn));
+}
+
+static inline void change_pageblock_type(struct zone *zone, struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+ __change_bit(pfn_to_bitidx(zone, pfn), pfn_to_usemap(zone, pfn));
+}
+
/*
* Used by page_zone() to look up the address of the struct zone whose
* id is encoded in the upper bits of page->flags
@@ -1847,6 +1860,38 @@ inline void setup_pageset(struct per_cpu
INIT_LIST_HEAD(&pcp->list);
}
+#ifndef CONFIG_SPARSEMEM
+#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
+/*
+ * Calculate the size of the zone->usemap in bytes rounded to an unsigned long
+ * Start by making sure zonesize is a multiple of MAX_ORDER-1 by rounding up
+ * Then figure 1 RCLM_TYPE worth of bits per MAX_ORDER-1, finally round up
+ * what is now in bits to nearest long in bits, then return it in bytes.
+ */
+static unsigned long __init usemap_size(unsigned long zonesize)
+{
+ unsigned long usemapsize;
+
+ usemapsize = roundup(zonesize, PAGES_PER_MAXORDER);
+ usemapsize = usemapsize >> (MAX_ORDER-1);
+ usemapsize = roundup(usemapsize, 8 * sizeof(unsigned long));
+
+ return usemapsize / 8;
+}
+
+static void __init setup_usemap(struct pglist_data *pgdat,
+ struct zone *zone, unsigned long zonesize)
+{
+ unsigned long usemapsize = usemap_size(zonesize);
+ zone->free_area_usemap = alloc_bootmem_node(pgdat, usemapsize);
+ memset(zone->free_area_usemap, ~RCLM_NORCLM, usemapsize);
+ memset(zone->free_area_usemap, RCLM_NORCLM, usemapsize/2);
+}
+#else
+static void inline setup_usemap(struct pglist_data *pgdat,
+ struct zone *zone, unsigned long zonesize) {}
+#endif /* CONFIG_SPARSEMEM */
+
#ifdef CONFIG_NUMA
/*
* Boot pageset table. One per cpu which is going to be used for all
@@ -2060,6 +2105,7 @@ static void __init free_area_init_core(s
zonetable_add(zone, nid, j, zone_start_pfn, size);
init_currently_empty_zone(zone, zone_start_pfn, size);
zone_start_pfn += size;
+ setup_usemap(pgdat, zone, size);
}
}
-
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