From: Christoph Lameter page allocator ZONE_HIGHMEM fixups 1. We do not need to do an #ifdef in si_meminfo since both counters in use are zero if !CONFIG_HIGHMEM. 2. Add #ifdef in si_meminfo_node instead to avoid referencing zone information for ZONE_HIGHMEM if we do not have HIGHMEM (may not be there after the following patches). 3. Replace the use of ZONE_HIGHMEM with MAX_NR_ZONES in build_zonelists_node 4. build_zonelists_node: Remove BUG_ON for ZONE_HIGHMEM. Zone will be optional soon and thus BUG_ON cannot be triggered anymore. 5. init_free_area_core: Replace a use of ZONE_HIGHMEM with NR_MAX_ZONES. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton --- mm/page_alloc.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff -puN mm/page_alloc.c~reduce-max_nr_zones-page-allocator-zone_highmem-cleanup mm/page_alloc.c --- a/mm/page_alloc.c~reduce-max_nr_zones-page-allocator-zone_highmem-cleanup +++ a/mm/page_alloc.c @@ -1199,13 +1199,8 @@ void si_meminfo(struct sysinfo *val) val->sharedram = 0; val->freeram = nr_free_pages(); val->bufferram = nr_blockdev_pages(); -#ifdef CONFIG_HIGHMEM val->totalhigh = totalhigh_pages; val->freehigh = nr_free_highpages(); -#else - val->totalhigh = 0; - val->freehigh = 0; -#endif val->mem_unit = PAGE_SIZE; } @@ -1218,8 +1213,13 @@ void si_meminfo_node(struct sysinfo *val val->totalram = pgdat->node_present_pages; val->freeram = nr_free_pages_pgdat(pgdat); +#ifdef CONFIG_HIGHMEM val->totalhigh = pgdat->node_zones[ZONE_HIGHMEM].present_pages; val->freehigh = pgdat->node_zones[ZONE_HIGHMEM].free_pages; +#else + val->totalhigh = 0; + val->freehigh = 0; +#endif val->mem_unit = PAGE_SIZE; } #endif @@ -1344,14 +1344,11 @@ static int __meminit build_zonelists_nod { struct zone *zone; - BUG_ON(zone_type > ZONE_HIGHMEM); + BUG_ON(zone_type >= MAX_NR_ZONES); do { zone = pgdat->node_zones + zone_type; if (populated_zone(zone)) { -#ifndef CONFIG_HIGHMEM - BUG_ON(zone_type > ZONE_NORMAL); -#endif zonelist->zones[nr_zones++] = zone; check_highest_zone(zone_type); } @@ -1979,7 +1976,7 @@ static void __meminit free_area_init_cor if (zholes_size) realsize -= zholes_size[j]; - if (j < ZONE_HIGHMEM) + if (!is_highmem_idx(j)) nr_kernel_pages += realsize; nr_all_pages += realsize; _