With sparse, pfn_to_page() becomes a somewhat more expensive
operation. This patch makes use of the guarentee that *_mem_map
will be contigious in sections aligned at MAX_ORDER to reduce
the number of pfn_to_page() calls.
By: Andy Whitcroft <[EMAIL PROTECTED]>
Signed-off-by: Dave Hansen <[EMAIL PROTECTED]>
---
memhotplug-dave/arch/i386/mm/discontig.c | 10 ++++++++--
memhotplug-dave/mm/bootmem.c | 14 +++++++++++++-
memhotplug-dave/mm/page_alloc.c | 8 +++++++-
3 files changed, 28 insertions(+), 4 deletions(-)
diff -puN arch/i386/mm/discontig.c~B-sparse-215-MAX_ORDER-optimisations
arch/i386/mm/discontig.c
--- memhotplug/arch/i386/mm/discontig.c~B-sparse-215-MAX_ORDER-optimisations
2005-03-16 15:46:41.000000000 -0800
+++ memhotplug-dave/arch/i386/mm/discontig.c 2005-03-16 15:46:41.000000000
-0800
@@ -408,10 +408,16 @@ void __init set_highmem_pages_init(int b
zone->name, zone->zone_pgdat->node_id,
zone_start_pfn, zone_end_pfn);
- for (node_pfn = zone_start_pfn; node_pfn < zone_end_pfn;
node_pfn++) {
+ /*
+ * Make use of the guarentee that *_mem_map will be
+ * contigious in sections aligned at MAX_ORDER.
+ */
+ page = pfn_to_page(zone_start_pfn);
+ for (node_pfn = zone_start_pfn; node_pfn < zone_end_pfn;
node_pfn++, page++) {
if (!pfn_valid(node_pfn))
continue;
- page = pfn_to_page(node_pfn);
+ if ((node_pfn & ((1 << MAX_ORDER) - 1)) == 0)
+ page = pfn_to_page(node_pfn);
one_highpage_init(page, node_pfn, bad_ppro);
}
}
diff -puN mm/bootmem.c~B-sparse-215-MAX_ORDER-optimisations mm/bootmem.c
--- memhotplug/mm/bootmem.c~B-sparse-215-MAX_ORDER-optimisations
2005-03-16 15:46:41.000000000 -0800
+++ memhotplug-dave/mm/bootmem.c 2005-03-16 15:46:41.000000000 -0800
@@ -274,10 +274,21 @@ static unsigned long __init free_all_boo
if (bdata->node_boot_start == 0 ||
ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG))
gofast = 1;
+
+ /*
+ * APW/XXX: we are making an assumption that our node_boot_start
+ * is aligned to BITS_PER_LONG ... is this valid/enforced.
+ */
+ /*
+ * Make use of the guarentee that *_mem_map will be
+ * contigious in sections aligned at MAX_ORDER.
+ */
+ page = pfn_to_page(pfn);
for (i = 0; i < idx; ) {
unsigned long v = ~map[i / BITS_PER_LONG];
- page = pfn_to_page(pfn);
+ if ((pfn & ((1 << MAX_ORDER) - 1)) == 0)
+ page = pfn_to_page(pfn);
if (gofast && v == ~0UL) {
int j, order;
@@ -306,6 +317,7 @@ static unsigned long __init free_all_boo
}
} else {
i+=BITS_PER_LONG;
+ page += BITS_PER_LONG;
}
pfn += BITS_PER_LONG;
}
diff -puN mm/page_alloc.c~B-sparse-215-MAX_ORDER-optimisations mm/page_alloc.c
--- memhotplug/mm/page_alloc.c~B-sparse-215-MAX_ORDER-optimisations
2005-03-16 15:46:41.000000000 -0800
+++ memhotplug-dave/mm/page_alloc.c 2005-03-16 15:46:41.000000000 -0800
@@ -1583,10 +1583,16 @@ void __init memmap_init_zone(unsigned lo
int end_pfn = start_pfn + size;
int pfn;
+ /*
+ * Make use of the guarentee that *_mem_map will be
+ * contigious in sections aligned at MAX_ORDER.
+ */
+ page = pfn_to_page(start_pfn);
for (pfn = start_pfn; pfn < end_pfn; pfn++, page++) {
if (!early_pfn_valid(pfn))
continue;
- page = pfn_to_page(pfn);
+ if ((pfn & ((1 << MAX_ORDER) - 1)) == 0)
+ page = pfn_to_page(pfn);
set_page_links(page, zone, nid, pfn);
set_page_count(page, 0);
reset_page_mapcount(page);
_
