This patch squeezes the ->zone field of struct page into flags, and
then uses an address calculation off the local zone_start_paddr to
recover the kvaddr of the page it represents.
Cheers,
Bill
diff -urN linux-2.4.15-pre5-virgin/arch/i386/config.in linux-2.4.15-pre5-bootmem/arch/i386/config.in
--- linux-2.4.15-pre5-virgin/arch/i386/config.in Mon Nov 19 13:07:07 2001
+++ linux-2.4.15-pre5-bootmem/arch/i386/config.in Mon Nov 19 01:30:10 2001
@@ -227,6 +227,12 @@
fi
fi
+if [ "$CONFIG_HIGHMEM" != "y" ]; then
+ bool 'Bloat the size of struct page.' CONFIG_PIGMEM
+else
+ define_bool CONFIG_PIGMEM y
+fi
+
source drivers/pci/Config.in
bool 'EISA support' CONFIG_EISA
diff -urN linux-2.4.15-pre5-virgin/include/asm-i386/pgtable.h linux-2.4.15-pre5-bootmem/include/asm-i386/pgtable.h
--- linux-2.4.15-pre5-virgin/include/asm-i386/pgtable.h Fri Nov 16 19:35:57 2001
+++ linux-2.4.15-pre5-bootmem/include/asm-i386/pgtable.h Mon Nov 19 12:59:03 2001
@@ -263,11 +263,39 @@
#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#ifdef CONFIG_PIGMEM
+
+#define PageZone(page) ((page)->zone)
+
+#define SetPageZone(page, zone_id) \
+ do { \
+ (page)->zone = zone_table[zone_id]; \
+ } while(0)
+
+#else /* !CONFIG_PIGMEM */
+
+#define PageZone(page) \
+ (zone_table[((page)->flags >> (BITS_PER_LONG - 5)) & 0x3UL])
+
+#define SetPageZone(page, zone_id) \
+ do { \
+ (page)->flags &= ~(0x3UL << (BITS_PER_LONG-5)); \
+ (page)->flags |= (zone_id & 0x3UL) << (BITS_PER_LONG-5);\
+ } while(0)
+
+#endif /* !CONFIG_PIGMEM */
+
/*
* Permanent address of a page. Obviously must never be
* called on a highmem page.
*/
+#if defined(CONFIG_PIGMEM) || defined(CONFIG_HIGHMEM)
#define page_address(page) ((page)->virtual)
+#else
+#define page_address(page) \
+ __va((((page) - PageZone(page)->zone_mem_map) << PAGE_SHIFT) \
+ + PageZone(page)->zone_start_paddr)
+#endif
#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
/*
diff -urN linux-2.4.15-pre5-virgin/include/linux/mm.h linux-2.4.15-pre5-bootmem/include/linux/mm.h
--- linux-2.4.15-pre5-virgin/include/linux/mm.h Mon Nov 19 13:07:08 2001
+++ linux-2.4.15-pre5-bootmem/include/linux/mm.h Mon Nov 19 12:59:05 2001
@@ -161,9 +161,15 @@
wait_queue_head_t wait; /* Page locked? Stand in line... */
struct page **pprev_hash; /* Complement to *next_hash. */
struct buffer_head * buffers; /* Buffer maps us to a disk block. */
+
+#if defined(CONFIG_PIGMEM) || defined(CONFIG_HIGHMEM)
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
+#endif
+
+#ifdef CONFIG_PIGMEM
struct zone_struct *zone; /* Memory zone we are in. */
+#endif
} mem_map_t;
/*
@@ -337,6 +343,13 @@
#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
+
+/*
+ * The PageZone and SetPageZone access methods must be defined
+ * elsewhere, in order to deal with arch-specific representation
+ * issues, for instance, the wordsize and needed number of zones
+ * to encode.
+ */
/*
* Error return values for the *_nopage functions
diff -urN linux-2.4.15-pre5-virgin/include/linux/mmzone.h linux-2.4.15-pre5-bootmem/include/linux/mmzone.h
--- linux-2.4.15-pre5-virgin/include/linux/mmzone.h Mon Nov 5 12:42:13 2001
+++ linux-2.4.15-pre5-bootmem/include/linux/mmzone.h Mon Nov 19 02:32:57 2001
@@ -62,6 +62,8 @@
unsigned long size;
} zone_t;
+extern zone_t *zone_table[];
+
#define ZONE_DMA 0
#define ZONE_NORMAL 1
#define ZONE_HIGHMEM 2
diff -urN linux-2.4.15-pre5-virgin/mm/page_alloc.c linux-2.4.15-pre5-bootmem/mm/page_alloc.c
--- linux-2.4.15-pre5-virgin/mm/page_alloc.c Fri Nov 16 19:36:11 2001
+++ linux-2.4.15-pre5-bootmem/mm/page_alloc.c Mon Nov 19 12:55:58 2001
@@ -54,7 +54,14 @@
/*
* Temporary debugging check.
*/
-#define BAD_RANGE(zone,x) (((zone) != (x)->zone) || (((x)-mem_map) < (zone)->zone_start_mapnr) || (((x)-mem_map) >= (zone)->zone_start_mapnr+(zone)->size))
+
+#define BAD_RANGE(zone, page) \
+( ((zone) != PageZone(page)) \
+ || ( (page) < (zone)->zone_mem_map) \
+ || (((page) - (zone)->zone_mem_map) >= (zone)->size) \
+)
+
+zone_t *zone_table[MAX_NR_ZONES];
/*
* Buddy system. Hairy. You really aren't expected to understand this
@@ -90,7 +97,7 @@
goto local_freelist;
back_local_freelist:
- zone = page->zone;
+ zone = PageZone(page);
mask = (~0UL) << order;
base = zone->zone_mem_map;
@@ -255,7 +262,9 @@
entry = local_pages->next;
do {
tmp = list_entry(entry, struct page, list);
- if (tmp->index == order && memclass(tmp->zone, classzone)) {
+ if (tmp->index == order
+ && memclass(PageZone(tmp), classzone)) {
+
list_del(entry);
current->nr_local_pages--;
set_page_count(tmp, 1);
@@ -650,6 +659,8 @@
for (i = 0; i < MAX_NR_ZONES; i++) {
unsigned long size = zones_size[i];
totalpages += size;
+
+ zone_table[i] = pgdat->node_zones + i;
}
realtotalpages = totalpages;
if (zholes_size)
@@ -732,9 +743,12 @@
for (i = 0; i < size; i++) {
struct page *page = mem_map + offset + i;
- page->zone = zone;
+ SetPageZone(page, j);
+
+#if defined(CONFIG_PIGMEM) || defined(CONFIG_HIGHMEM)
if (j != ZONE_HIGHMEM)
page->virtual = __va(zone_start_paddr);
+#endif
zone_start_paddr += PAGE_SIZE;
}
diff -urN linux-2.4.15-pre5-virgin/mm/vmscan.c linux-2.4.15-pre5-bootmem/mm/vmscan.c
--- linux-2.4.15-pre5-virgin/mm/vmscan.c Mon Nov 19 13:07:08 2001
+++ linux-2.4.15-pre5-bootmem/mm/vmscan.c Mon Nov 19 01:26:04 2001
@@ -58,7 +58,7 @@
return 0;
/* Don't bother replenishing zones not under pressure.. */
- if (!memclass(page->zone, classzone))
+ if (!memclass(PageZone(page), classzone))
return 0;
if (TryLockPage(page))
@@ -225,7 +225,7 @@
count = swap_out_pmd(mm, vma, pmd, address, end, count, classzone);
if (!count)
break;
- debug_lock_break(551);
+ debug_lock_break(1);
#if 0
if (conditional_schedule_needed())
return count;
@@ -396,7 +396,7 @@
if (unlikely(!page_count(page)))
continue;
- if (!memclass(page->zone, classzone))
+ if (!memclass(PageZone(page), classzone))
continue;
/* Racy check to avoid trylocking when not worthwhile */
--
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