diff options
author | Dave Hansen <haveblue@us.ibm.com> | 2004-08-22 22:49:13 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-22 22:49:13 -0700 |
commit | fde9e1da4c3abf6e445aa56325c75c25ffe89a8b (patch) | |
tree | 5efaa947f2b154e16c3d0c83d49ed98f862e08b7 /mm | |
parent | 47ad9591d188f1ff0c13a52d37a2eb4cc510f364 (diff) | |
download | history-fde9e1da4c3abf6e445aa56325c75c25ffe89a8b.tar.gz |
[PATCH] break out zone free list initialization
The following patch removes the individual free area initialization from
free_area_init_core(), and puts it in a new function
zone_init_free_lists(). It also creates pages_to_bitmap_size(), which is
then used in zone_init_free_lists() as well as several times in my free
area bitmap resizing patch.
First of all, I think it looks nicer this way, but it's also necessary to
have this if you want to initialize a zone after system boot, like if a
NUMA node was hot-added. In any case, it should be functionally equivalent
to the old code.
Compiles and boots on x86. I've been running with this for a few weeks,
and haven't seen any problems with it yet.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/page_alloc.c | 84 |
1 files changed, 47 insertions, 37 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index a3f2a7407ac77b..a1e8501808a554 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1398,6 +1398,52 @@ void __init memmap_init_zone(struct page *start, unsigned long size, int nid, } } +/* + * Page buddy system uses "index >> (i+1)", where "index" is + * at most "size-1". + * + * The extra "+3" is to round down to byte size (8 bits per byte + * assumption). Thus we get "(size-1) >> (i+4)" as the last byte + * we can access. + * + * The "+1" is because we want to round the byte allocation up + * rather than down. So we should have had a "+7" before we shifted + * down by three. Also, we have to add one as we actually _use_ the + * last bit (it's [0,n] inclusive, not [0,n[). + * + * So we actually had +7+1 before we shift down by 3. But + * (n+8) >> 3 == (n >> 3) + 1 (modulo overflows, which we do not have). + * + * Finally, we LONG_ALIGN because all bitmap operations are on longs. + */ +unsigned long pages_to_bitmap_size(unsigned long order, unsigned long nr_pages) +{ + unsigned long bitmap_size; + + bitmap_size = (nr_pages-1) >> (order+4); + bitmap_size = LONG_ALIGN(bitmap_size+1); + + return bitmap_size; +} + +void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, unsigned long size) +{ + int order; + for (order = 0; ; order++) { + unsigned long bitmap_size; + + INIT_LIST_HEAD(&zone->free_area[order].free_list); + if (order == MAX_ORDER-1) { + zone->free_area[order].map = NULL; + break; + } + + bitmap_size = pages_to_bitmap_size(order, size); + zone->free_area[order].map = + (unsigned long *) alloc_bootmem_node(pgdat, bitmap_size); + } +} + #ifndef __HAVE_ARCH_MEMMAP_INIT #define memmap_init(start, size, nid, zone, start_pfn) \ memmap_init_zone((start), (size), (nid), (zone), (start_pfn)) @@ -1514,43 +1560,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat, zone_start_pfn += size; lmem_map += size; - for (i = 0; ; i++) { - unsigned long bitmap_size; - - INIT_LIST_HEAD(&zone->free_area[i].free_list); - if (i == MAX_ORDER-1) { - zone->free_area[i].map = NULL; - break; - } - - /* - * Page buddy system uses "index >> (i+1)", - * where "index" is at most "size-1". - * - * The extra "+3" is to round down to byte - * size (8 bits per byte assumption). Thus - * we get "(size-1) >> (i+4)" as the last byte - * we can access. - * - * The "+1" is because we want to round the - * byte allocation up rather than down. So - * we should have had a "+7" before we shifted - * down by three. Also, we have to add one as - * we actually _use_ the last bit (it's [0,n] - * inclusive, not [0,n[). - * - * So we actually had +7+1 before we shift - * down by 3. But (n+8) >> 3 == (n >> 3) + 1 - * (modulo overflows, which we do not have). - * - * Finally, we LONG_ALIGN because all bitmap - * operations are on longs. - */ - bitmap_size = (size-1) >> (i+4); - bitmap_size = LONG_ALIGN(bitmap_size+1); - zone->free_area[i].map = - (unsigned long *) alloc_bootmem_node(pgdat, bitmap_size); - } + zone_init_free_lists(pgdat, zone, zone->spanned_pages); } } |