[PATCH] Avoiding fragmentation through different allocator V2

From: Mel Gorman
Date: Thu Jan 13 2005 - 11:12:15 EST

The patch is against 2.6.11-rc1 and I'm willing to stand by it's
stability. I'm also confident it does it's job pretty well so I'd like it
to be considered for inclusion.

For me, the next stage is to write a linear scanner that goes through the
address space to free up a high-order block of pages on demand. This will
be a tricky job so it'll take me quite a while.



Changelog since V1

o Update patch to 2.6.11-rc1
o Cleaned up bug where memory was wasted on a large bitmap
o Extended fallback_count bean counters to show the fallback count for each
allocation type
o Better commenting

This patch divides allocations into three different types of allocations;

UserReclaimable - These are userspace pages that are easily reclaimable. Right
now, I'm putting all allocations of GFP_USER and GFP_HIGHUSER as
well as disk-buffer pages into this category. These pages are trivially
reclaimed by writing the page out to swap or syncing with backing
storage

KernelReclaimable - These are pages allocated by the kernel that are easily
reclaimed. This is stuff like inode caches, dcache, buffer_heads etc.
These type of pages potentially could be reclaimed by dumping the
caches and reaping the slabs (drastic, but you get the idea).

KernelNonReclaimable - These are pages that are allocated by the kernel that
are not trivially reclaimed. For example, the memory allocated for a
loaded module would be in this category. By default, allocations are
considered to be of this type

Instead of having one global MAX_ORDER-sized array of free lists, there are
three, one for each type of allocation. Finally, there is a list of pages of
size 2^MAX_ORDER which is a global pool of the largest pages the kernel deals
with.

Once a 2^MAX_ORDER block of pages it split for a type of allocation, it is
added to the free-lists for that type, in effect reserving it. Hence, over
time, pages of the different types can be clustered together. This means that
if we wanted 2^MAX_ORDER number of pages, we could linearly scan a block of
pages allocated for UserReclaimable and page each of them out.

Fallback is used when there are no 2^MAX_ORDER pages available and there
are no free pages of the desired type. The fallback lists were chosen in a
way that keeps the most easily reclaimable pages together.

Signed-off-by: Mel Gorman <mel@xxxxxxxxx>

diff -rup linux-2.6.11-rc1-clean/fs/buffer.c linux-2.6.11-rc1-mbuddy/fs/buffer.c
--- linux-2.6.11-rc1-clean/fs/buffer.c 2005-01-12 04:01:23.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/fs/buffer.c 2005-01-13 10:56:30.000000000 +0000
@@ -1134,7 +1134,8 @@ grow_dev_page(struct block_device *bdev,
struct page *page;
struct buffer_head *bh;

- page = find_or_create_page(inode->i_mapping, index, GFP_NOFS);
+ page = find_or_create_page(inode->i_mapping, index,
+ GFP_NOFS | __GFP_USERRCLM);
if (!page)
return NULL;

@@ -2997,7 +2998,8 @@ static void recalc_bh_state(void)

struct buffer_head *alloc_buffer_head(int gfp_flags)
{
- struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);
+ struct buffer_head *ret = kmem_cache_alloc(bh_cachep,
+ gfp_flags|__GFP_KERNRCLM);
if (ret) {
preempt_disable();
__get_cpu_var(bh_accounting).nr++;
diff -rup linux-2.6.11-rc1-clean/fs/dcache.c linux-2.6.11-rc1-mbuddy/fs/dcache.c
--- linux-2.6.11-rc1-clean/fs/dcache.c 2005-01-12 04:00:09.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/fs/dcache.c 2005-01-13 10:56:30.000000000 +0000
@@ -715,7 +715,8 @@ struct dentry *d_alloc(struct dentry * p
struct dentry *dentry;
char *dname;

- dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL);
+ dentry = kmem_cache_alloc(dentry_cache,
+ GFP_KERNEL|__GFP_KERNRCLM);
if (!dentry)
return NULL;

diff -rup linux-2.6.11-rc1-clean/fs/ext2/super.c linux-2.6.11-rc1-mbuddy/fs/ext2/super.c
--- linux-2.6.11-rc1-clean/fs/ext2/super.c 2005-01-12 04:01:24.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/fs/ext2/super.c 2005-01-13 10:56:30.000000000 +0000
@@ -137,7 +137,7 @@ static kmem_cache_t * ext2_inode_cachep;
static struct inode *ext2_alloc_inode(struct super_block *sb)
{
struct ext2_inode_info *ei;
- ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL);
+ ei = (struct ext2_inode_info *)kmem_cache_alloc(ext2_inode_cachep, SLAB_KERNEL|__GFP_KERNRCLM);
if (!ei)
return NULL;
#ifdef CONFIG_EXT2_FS_POSIX_ACL
diff -rup linux-2.6.11-rc1-clean/fs/ext3/super.c linux-2.6.11-rc1-mbuddy/fs/ext3/super.c
--- linux-2.6.11-rc1-clean/fs/ext3/super.c 2005-01-12 04:02:11.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/fs/ext3/super.c 2005-01-13 10:56:30.000000000 +0000
@@ -434,7 +434,7 @@ static struct inode *ext3_alloc_inode(st
{
struct ext3_inode_info *ei;

- ei = kmem_cache_alloc(ext3_inode_cachep, SLAB_NOFS);
+ ei = kmem_cache_alloc(ext3_inode_cachep, SLAB_NOFS|__GFP_KERNRCLM);
if (!ei)
return NULL;
#ifdef CONFIG_EXT3_FS_POSIX_ACL
diff -rup linux-2.6.11-rc1-clean/fs/ntfs/inode.c linux-2.6.11-rc1-mbuddy/fs/ntfs/inode.c
--- linux-2.6.11-rc1-clean/fs/ntfs/inode.c 2005-01-12 04:01:45.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/fs/ntfs/inode.c 2005-01-13 10:56:30.000000000 +0000
@@ -318,7 +318,7 @@ struct inode *ntfs_alloc_big_inode(struc

ntfs_debug("Entering.");
ni = (ntfs_inode *)kmem_cache_alloc(ntfs_big_inode_cache,
- SLAB_NOFS);
+ SLAB_NOFS|__GFP_KERNRCLM);
if (likely(ni != NULL)) {
ni->state = 0;
return VFS_I(ni);
@@ -343,7 +343,8 @@ static inline ntfs_inode *ntfs_alloc_ext
ntfs_inode *ni;

ntfs_debug("Entering.");
- ni = (ntfs_inode *)kmem_cache_alloc(ntfs_inode_cache, SLAB_NOFS);
+ ni = (ntfs_inode *)kmem_cache_alloc(ntfs_inode_cache,
+ SLAB_NOFS|__GFP_KERNRCLM);
if (likely(ni != NULL)) {
ni->state = 0;
return ni;
diff -rup linux-2.6.11-rc1-clean/include/linux/gfp.h linux-2.6.11-rc1-mbuddy/include/linux/gfp.h
--- linux-2.6.11-rc1-clean/include/linux/gfp.h 2005-01-12 04:00:35.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/include/linux/gfp.h 2005-01-13 14:18:06.000000000 +0000
@@ -38,21 +38,24 @@ struct vm_area_struct;
#define __GFP_NO_GROW 0x2000 /* Slab internal usage */
#define __GFP_COMP 0x4000 /* Add compound page metadata */
#define __GFP_ZERO 0x8000 /* Return zeroed page on success */
+#define __GFP_KERNRCLM 0x10000 /* Kernel page that is easily reclaimable */
+#define __GFP_USERRCLM 0x20000 /* User is a userspace user */

-#define __GFP_BITS_SHIFT 16 /* Room for 16 __GFP_FOO bits */
+#define __GFP_BITS_SHIFT 17 /* Room for 17 __GFP_FOO bits */
#define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)

/* if you forget to add the bitmask here kernel will crash, period */
#define GFP_LEVEL_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS| \
__GFP_COLD|__GFP_NOWARN|__GFP_REPEAT| \
- __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP)
+ __GFP_NOFAIL|__GFP_NORETRY|__GFP_NO_GROW|__GFP_COMP| \
+ __GFP_USERRCLM|__GFP_KERNRCLM)

#define GFP_ATOMIC (__GFP_HIGH)
#define GFP_NOIO (__GFP_WAIT)
#define GFP_NOFS (__GFP_WAIT | __GFP_IO)
#define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS)
-#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS)
-#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM)
+#define GFP_USER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_USERRCLM)
+#define GFP_HIGHUSER (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HIGHMEM | __GFP_USERRCLM)

/* Flag - indicates that the buffer will be suitable for DMA. Ignored on some
platforms, used as appropriate on others */
diff -rup linux-2.6.11-rc1-clean/include/linux/mmzone.h linux-2.6.11-rc1-mbuddy/include/linux/mmzone.h
--- linux-2.6.11-rc1-clean/include/linux/mmzone.h 2005-01-12 04:01:17.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/include/linux/mmzone.h 2005-01-13 14:24:27.000000000 +0000
@@ -19,6 +19,10 @@
#else
#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
#endif
+#define ALLOC_TYPES 3
+#define ALLOC_KERNNORCLM 0
+#define ALLOC_KERNRCLM 1
+#define ALLOC_USERRCLM 2

struct free_area {
struct list_head free_list;
@@ -131,8 +135,37 @@ struct zone {
* free areas of different sizes
*/
spinlock_t lock;
- struct free_area free_area[MAX_ORDER];

+ /*
+ * There are ALLOC_TYPE number of MAX_ORDER free lists. Once a
+ * MAX_ORDER block of pages has been split for an allocation type,
+ * the whole block is reserved for that type of allocation. The
+ * types are User Reclaimable, Kernel Reclaimable and Kernel
+ * Non-reclaimable. The objective is to reduce fragmentation
+ * overall
+ */
+ struct free_area free_area_lists[ALLOC_TYPES][MAX_ORDER];
+
+ /*
+ * This is a list of page blocks of 2^MAX_ORDER. Once one of
+ * these are split, the buddy is added to the appropriate
+ * free_area_lists. When the buddies are later merged, they
+ * are placed back here
+ */
+ struct free_area free_area_global;
+
+ /*
+ * This map tracks what each 2^MAX_ORDER sized block has been used for.
+ * Each 2^MAX_ORDER block have pages has 2 bits in this map to remember
+ * what the block is for. When a page is freed, it's index within this
+ * bitmap is calculated using (address >> MAX_ORDER) * 2 . This means
+ * that pages will always be freed into the correct list in
+ * free_area_lists
+ *
+ * The bits are set when a 2^MAX_ORDER block of pages is split
+ */
+
+ unsigned long *free_area_usemap;

ZONE_PADDING(_pad1_)

diff -rup linux-2.6.11-rc1-clean/mm/page_alloc.c linux-2.6.11-rc1-mbuddy/mm/page_alloc.c
--- linux-2.6.11-rc1-clean/mm/page_alloc.c 2005-01-12 04:00:02.000000000 +0000
+++ linux-2.6.11-rc1-mbuddy/mm/page_alloc.c 2005-01-13 14:58:06.000000000 +0000
@@ -46,9 +46,31 @@ unsigned long totalhigh_pages;
long nr_swap_pages;
int sysctl_lower_zone_protection = 0;

+/* Bean counters for the per-type buddy allocator */
+int fallback_count[ALLOC_TYPES] = { 0, 0, 0};
+int drastic_fallback_count=0;
+int global_steal=0;
+int global_refill=0;
+int kernnorclm_count=0;
+int kernrclm_count=0;
+int userrclm_count=0;
+
EXPORT_SYMBOL(totalram_pages);
EXPORT_SYMBOL(nr_swap_pages);

+/**
+ * The allocator tries to put allocations of the same type in the
+ * same 2^MAX_ORDER blocks of pages. When memory is low, this may
+ * not be possible so this describes what order they should fall
+ * back on
+ */
+int fallback_allocs[ALLOC_TYPES][ALLOC_TYPES] = {
+ { ALLOC_KERNNORCLM, ALLOC_KERNRCLM, ALLOC_USERRCLM },
+ { ALLOC_KERNRCLM, ALLOC_KERNNORCLM, ALLOC_USERRCLM },
+ { ALLOC_USERRCLM, ALLOC_KERNNORCLM, ALLOC_KERNRCLM }
+};
+
+
/*
* Used by page_zone() to look up the address of the struct zone whose
* id is encoded in the upper bits of page->flags
@@ -57,6 +79,7 @@ struct zone *zone_table[1 << (ZONES_SHIF
EXPORT_SYMBOL(zone_table);

static char *zone_names[MAX_NR_ZONES] = { "DMA", "Normal", "HighMem" };
+static char *type_names[ALLOC_TYPES] = { "KernNoRclm", "KernRclm", "UserRclm"};
int min_free_kbytes = 1024;

unsigned long __initdata nr_kernel_pages;
@@ -103,6 +126,48 @@ static void bad_page(const char *functio
tainted |= TAINT_BAD_PAGE;
}

+/*
+ * Return what type of use the 2^MAX_ORDER block of pages is in use for
+ * that the given page is part of
+ */
+static int get_pageblock_type(struct page *page) {
+ struct zone *zone = page_zone(page);
+ int pageidx = (page - zone->zone_mem_map) >> MAX_ORDER;
+ int bitidx = pageidx * 2;
+
+ /* Bit 1 will be set if the block is kernel reclaimable */
+ if (test_bit(bitidx,zone->free_area_usemap)) return ALLOC_KERNRCLM;
+
+ /* Bit 2 will be set if the block is user reclaimable */
+ if (test_bit(bitidx+1, zone->free_area_usemap)) return ALLOC_USERRCLM;
+
+ return ALLOC_KERNNORCLM;
+}
+
+static void set_pageblock_type(struct page *page, int type) {
+ int bit1, bit2;
+ struct zone *zone = page_zone(page);
+ int pageidx = (page - zone->zone_mem_map) >> MAX_ORDER;
+ int bitidx = pageidx * 2;
+ bit1 = bit2 = 0;
+
+ if (type == ALLOC_KERNRCLM) {
+ set_bit(bitidx, zone->free_area_usemap);
+ clear_bit(bitidx+1, zone->free_area_usemap);
+ return;
+ }
+
+ if (type == ALLOC_USERRCLM) {
+ clear_bit(bitidx, zone->free_area_usemap);
+ set_bit(bitidx+1, zone->free_area_usemap);
+ return;
+ }
+
+ clear_bit(bitidx, zone->free_area_usemap);
+ clear_bit(bitidx+1, zone->free_area_usemap);
+
+}
+
#ifndef CONFIG_HUGETLB_PAGE
#define prep_compound_page(page, order) do { } while (0)
#define destroy_compound_page(page, order) do { } while (0)
@@ -231,6 +296,7 @@ static inline void __free_pages_bulk (st
unsigned long page_idx;
struct page *coalesced;
int order_size = 1 << order;
+ struct free_area *area;

if (unlikely(order))
destroy_compound_page(page, order);
@@ -240,9 +306,12 @@ static inline void __free_pages_bulk (st
BUG_ON(page_idx & (order_size - 1));
BUG_ON(bad_range(zone, page));

+ /* Select the area to use for freeing based on the type */
+ struct free_area *freelist =
+ zone->free_area_lists[get_pageblock_type(page)];
+
zone->free_pages += order_size;
while (order < MAX_ORDER-1) {
- struct free_area *area;
struct page *buddy;
int buddy_idx;

@@ -254,16 +323,29 @@ static inline void __free_pages_bulk (st
break;
/* Move the buddy up one level. */
list_del(&buddy->lru);
- area = zone->free_area + order;
+ area = freelist + order;
area->nr_free--;
rmv_page_order(buddy);
page_idx &= buddy_idx;
order++;
}
+
+ /*
+ * If a MAX_ORDER block of pages is being freed, it is
+ * no longer reserved for a particular type of allocation
+ * so put it in the global list
+ */
+ if (order >= MAX_ORDER-1) {
+ area = &(zone->free_area_global);
+ global_refill++;
+ } else {
+ area = freelist + order;
+ }
+
coalesced = base + page_idx;
set_page_order(coalesced, order);
- list_add(&coalesced->lru, &zone->free_area[order].free_list);
- zone->free_area[order].nr_free++;
+ list_add(&coalesced->lru, &area->free_list);
+ area->nr_free++;
}

static inline void free_pages_check(const char *function, struct page *page)
@@ -310,6 +392,7 @@ free_pages_bulk(struct zone *zone, int c
zone->pages_scanned = 0;
while (!list_empty(list) && count--) {
page = list_entry(list->prev, struct page, lru);
+
/* have to delete it as __free_pages_bulk list manipulates */
list_del(&page->lru);
__free_pages_bulk(page, base, zone, order);
@@ -420,14 +503,36 @@ static void prep_new_page(struct page *p
* Do the hard work of removing an element from the buddy allocator.
* Call me with the zone->lock already held.
*/
-static struct page *__rmqueue(struct zone *zone, unsigned int order)
+static struct page *__rmqueue(struct zone *zone, unsigned int order, int flags)
{
struct free_area * area;
unsigned int current_order;
struct page *page;
+ int global_split=0;
+
+ /* Select area to use based on gfp_flags */
+ int alloctype;
+ int retry_count=0;
+ if (flags & __GFP_USERRCLM) {
+ alloctype = ALLOC_USERRCLM;
+ userrclm_count++;
+ }
+ else if (flags & __GFP_KERNRCLM) {
+ alloctype = ALLOC_KERNRCLM;
+ kernrclm_count++;
+ } else {
+ alloctype = ALLOC_KERNNORCLM;
+ kernnorclm_count++;
+ }

+ /* Ok, pick the fallback order based on the type */
+ int *fallback_list = fallback_allocs[alloctype];
+
+retry:
for (current_order = order; current_order < MAX_ORDER; ++current_order) {
- area = zone->free_area + current_order;
+ alloctype = fallback_list[retry_count];
+ area = zone->free_area_lists[alloctype] + current_order;
+
if (list_empty(&area->free_list))
continue;

@@ -439,6 +544,34 @@ static struct page *__rmqueue(struct zon
return expand(zone, page, order, current_order, area);
}

+ /* Take from the global pool if this is the first attempt */
+ if (!global_split && !list_empty(&(zone->free_area_global.free_list))){
+ /*
+ * Remove a MAX_ORDER block from the global pool and add
+ * it to the list of desired alloc_type
+ */
+ page = list_entry(zone->free_area_global.free_list.next,
+ struct page, lru);
+ list_del(&page->lru);
+ list_add(&page->lru,
+ &(zone->free_area_lists[alloctype][MAX_ORDER-1].free_list));
+ global_steal++;
+ global_split=1;
+
+ /* Mark this block of pages as for use with this alloc type */
+ set_pageblock_type(page, alloctype);
+
+ goto retry;
+ }
+
+ /*
+ * Here, the alloc type lists has been depleted as well as the global
+ * pool, so fallback
+ */
+ retry_count++;
+ fallback_count[alloctype]++;
+ if (retry_count != ALLOC_TYPES) goto retry;
+
return NULL;
}

@@ -448,7 +581,8 @@ static struct page *__rmqueue(struct zon
* Returns the number of new pages which were placed at *list.
*/
static int rmqueue_bulk(struct zone *zone, unsigned int order,
- unsigned long count, struct list_head *list)
+ unsigned long count, struct list_head *list,
+ int gfp_flags)
{
unsigned long flags;
int i;
@@ -457,7 +591,7 @@ static int rmqueue_bulk(struct zone *zon

spin_lock_irqsave(&zone->lock, flags);
for (i = 0; i < count; ++i) {
- page = __rmqueue(zone, order);
+ page = __rmqueue(zone, order, gfp_flags);
if (page == NULL)
break;
allocated++;
@@ -493,7 +627,7 @@ static void __drain_pages(unsigned int c
void mark_free_pages(struct zone *zone)
{
unsigned long zone_pfn, flags;
- int order;
+ int order, type;
struct list_head *curr;

if (!zone->spanned_pages)
@@ -503,14 +637,17 @@ void mark_free_pages(struct zone *zone)
for (zone_pfn = 0; zone_pfn < zone->spanned_pages; ++zone_pfn)
ClearPageNosaveFree(pfn_to_page(zone_pfn + zone->zone_start_pfn));

- for (order = MAX_ORDER - 1; order >= 0; --order)
- list_for_each(curr, &zone->free_area[order].free_list) {
- unsigned long start_pfn, i;
+ for (type=0; type < ALLOC_TYPES; type++) {

- start_pfn = page_to_pfn(list_entry(curr, struct page, lru));
+ for (order = MAX_ORDER - 1; order >= 0; --order)
+ list_for_each(curr, &zone->free_area_lists[type][order].free_list) {
+ unsigned long start_pfn, i;
+
+ start_pfn = page_to_pfn(list_entry(curr, struct page, lru));

- for (i=0; i < (1<<order); i++)
- SetPageNosaveFree(pfn_to_page(start_pfn+i));
+ for (i=0; i < (1<<order); i++)
+ SetPageNosaveFree(pfn_to_page(start_pfn+i));
+ }
}
spin_unlock_irqrestore(&zone->lock, flags);
}
@@ -612,14 +749,15 @@ buffered_rmqueue(struct zone *zone, int
struct page *page = NULL;
int cold = !!(gfp_flags & __GFP_COLD);

- if (order == 0) {
+ if (order == 0 && (gfp_flags & __GFP_USERRCLM)) {
struct per_cpu_pages *pcp;

pcp = &zone->pageset[get_cpu()].pcp[cold];
local_irq_save(flags);
if (pcp->count <= pcp->low)
pcp->count += rmqueue_bulk(zone, 0,
- pcp->batch, &pcp->list);
+ pcp->batch, &pcp->list,
+ gfp_flags);
if (pcp->count) {
page = list_entry(pcp->list.next, struct page, lru);
list_del(&page->lru);
@@ -631,7 +769,7 @@ buffered_rmqueue(struct zone *zone, int

if (page == NULL) {
spin_lock_irqsave(&zone->lock, flags);
- page = __rmqueue(zone, order);
+ page = __rmqueue(zone, order, gfp_flags);
spin_unlock_irqrestore(&zone->lock, flags);
}

@@ -658,7 +796,7 @@ int zone_watermark_ok(struct zone *z, in
{
/* free_pages my go negative - that's OK */
long min = mark, free_pages = z->free_pages - (1 << order) + 1;
- int o;
+ int o, type;

if (gfp_high)
min -= min / 2;
@@ -667,15 +805,17 @@ int zone_watermark_ok(struct zone *z, in

if (free_pages <= min + z->protection[alloc_type])
return 0;
- for (o = 0; o < order; o++) {
- /* At the next order, this order's pages become unavailable */
- free_pages -= z->free_area[o].nr_free << o;
+ for (type=0; type < ALLOC_TYPES; type++) {
+ for (o = 0; o < order; o++) {
+ /* At the next order, this order's pages become unavailable */
+ free_pages -= z->free_area_lists[type][o].nr_free << o;

- /* Require fewer higher order pages to be free */
- min >>= 1;
+ /* Require fewer higher order pages to be free */
+ min >>= 1;

- if (free_pages <= min)
- return 0;
+ if (free_pages <= min)
+ return 0;
+ }
}
return 1;
}
@@ -1124,6 +1264,7 @@ void show_free_areas(void)
unsigned long inactive;
unsigned long free;
struct zone *zone;
+ int type;

for_each_zone(zone) {
show_node(zone);
@@ -1216,8 +1357,10 @@ void show_free_areas(void)

spin_lock_irqsave(&zone->lock, flags);
for (order = 0; order < MAX_ORDER; order++) {
- nr = zone->free_area[order].nr_free;
- total += nr << order;
+ for (type=0; type < ALLOC_TYPES; type++) {
+ nr = zone->free_area_lists[type][order].nr_free;
+ total += nr << order;
+ }
printk("%lu*%lukB ", nr, K(1UL) << order);
}
spin_unlock_irqrestore(&zone->lock, flags);
@@ -1515,10 +1658,26 @@ void zone_init_free_lists(struct pglist_
unsigned long size)
{
int order;
- for (order = 0; order < MAX_ORDER ; order++) {
- INIT_LIST_HEAD(&zone->free_area[order].free_list);
- zone->free_area[order].nr_free = 0;
- }
+ int type;
+ struct free_area *area;
+
+ /* Initialse the three size ordered lists of free_areas */
+ for (type=0; type < ALLOC_TYPES; type++) {
+
+ for (order = 0; ; order++) {
+ area = zone->free_area_lists[type];
+
+ INIT_LIST_HEAD(&area[order].free_list);
+ area[order].nr_free = 0;
+ if (order == MAX_ORDER-1) {
+ break;
+ }
+ }
+ }
+
+ /* Initialise the global pool of 2^size pages */
+ INIT_LIST_HEAD(&zone->free_area_global.free_list);
+ zone->free_area_global.nr_free=0;
}

#ifndef __HAVE_ARCH_MEMMAP_INIT
@@ -1637,6 +1796,11 @@ static void __init free_area_init_core(s
zone_start_pfn += size;

zone_init_free_lists(pgdat, zone, zone->spanned_pages);
+ zone->free_area_usemap =
+ (unsigned long *)alloc_bootmem_node(pgdat,
+ ((size >> MAX_ORDER) * 2 + 8) / 8);
+ memset((unsigned long *)zone->free_area_usemap, ALLOC_KERNNORCLM,
+ ((size >> MAX_ORDER) * 2 + 8) / 8);
}
}

@@ -1714,19 +1878,90 @@ static int frag_show(struct seq_file *m,
struct zone *zone;
struct zone *node_zones = pgdat->node_zones;
unsigned long flags;
- int order;
+ int order, type;
+ struct list_head *elem;

- for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
- if (!zone->present_pages)
- continue;

- spin_lock_irqsave(&zone->lock, flags);
- seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
- for (order = 0; order < MAX_ORDER; ++order)
- seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
- spin_unlock_irqrestore(&zone->lock, flags);
- seq_putc(m, '\n');
- }
+ /* Show global fragmentation statistics */
+ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+ if (!zone->present_pages)
+ continue;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
+ unsigned long nr_bufs = 0;
+ for (order = 0; order < MAX_ORDER-1; ++order) {
+ nr_bufs = 0;
+
+ for (type=0; type < ALLOC_TYPES; type++) {
+ list_for_each(elem, &(zone->free_area_lists[type][order].free_list))
+ ++nr_bufs;
+ }
+ seq_printf(m, "%6lu ", nr_bufs);
+ }
+
+ /* Scan global list */
+ nr_bufs = 0;
+ list_for_each(elem, &(zone->free_area_global.free_list))
+ ++nr_bufs;
+ seq_printf(m, "%6lu ", nr_bufs);
+
+ spin_unlock_irqrestore(&zone->lock, flags);
+ seq_putc(m, '\n');
+ }
+
+ /* Show statistics for each allocation type */
+ seq_printf(m, "\nPer-allocation-type statistics");
+ for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+ if (!zone->present_pages)
+ continue;
+
+ spin_lock_irqsave(&zone->lock, flags);
+ unsigned long nr_bufs = 0;
+ for (type=0; type < ALLOC_TYPES; type++) {
+ seq_printf(m, "\nNode %d, zone %8s, type %10s",
+ pgdat->node_id, zone->name,
+ type_names[type]);
+ struct list_head *elem;
+ for (order = 0; order < MAX_ORDER; ++order) {
+ nr_bufs = 0;
+
+ list_for_each(elem, &(zone->free_area_lists[type][order].free_list))
+ ++nr_bufs;
+ seq_printf(m, "%6lu ", nr_bufs);
+ }
+ }
+
+ /* Scan global list */
+ seq_printf(m, "\n");
+ seq_printf(m, "Node %d, zone %8s, type %10s",
+ pgdat->node_id, zone->name,
+ "MAX_ORDER");
+ nr_bufs = 0;
+ list_for_each(elem, &(zone->free_area_global.free_list))
+ ++nr_bufs;
+ seq_printf(m, "%6lu ", nr_bufs);
+
+ spin_unlock_irqrestore(&zone->lock, flags);
+ seq_putc(m, '\n');
+ }
+
+ /* Show bean counters */
+ seq_printf(m, "\nGlobal beancounters\n");
+ seq_printf(m, "Global steals: %d\n", global_steal);
+ seq_printf(m, "Global refills: %d\n", global_refill);
+ seq_printf(m, "KernNoRclm allocs: %d\n", kernnorclm_count);
+ seq_printf(m, "KernRclm allocs: %d\n", kernrclm_count);
+ seq_printf(m, "UserRclm allocs: %d\n", userrclm_count);
+ seq_printf(m, "%-10s Fallback count: %d\n", type_names[0],
+ fallback_count[0]);
+ seq_printf(m, "%-10s Fallback count: %d\n", type_names[1],
+ fallback_count[1]);
+ seq_printf(m, "%-10s Fallback count: %d\n", type_names[2],
+ fallback_count[2]);
+
+
+
return 0;
}

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