diff options
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r-- | mm/page_alloc.c | 311 |
1 files changed, 169 insertions, 142 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 32e796af12a..0a502e99ee2 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -546,7 +546,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) /* * permit the bootmem allocator to evade page validation on high-order frees */ -void __init __free_pages_bootmem(struct page *page, unsigned int order) +void __free_pages_bootmem(struct page *page, unsigned int order) { if (order == 0) { __ClearPageReserved(page); @@ -632,7 +632,7 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) if (PageReserved(page)) return 1; - page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_readahead | + page->flags &= ~(1 << PG_uptodate | 1 << PG_error | 1 << PG_reclaim | 1 << PG_referenced | 1 << PG_arch_1 | 1 << PG_owner_priv_1 | 1 << PG_mappedtodisk); set_page_private(page, 0); @@ -1050,7 +1050,7 @@ void split_page(struct page *page, unsigned int order) * we cheat by calling it from here, in the order > 0 path. Saves a branch * or two. */ -static struct page *buffered_rmqueue(struct zonelist *zonelist, +static struct page *buffered_rmqueue(struct zone *preferred_zone, struct zone *zone, int order, gfp_t gfp_flags) { unsigned long flags; @@ -1102,7 +1102,7 @@ again: } __count_zone_vm_events(PGALLOC, zone, 1 << order); - zone_statistics(zonelist, zone); + zone_statistics(preferred_zone, zone); local_irq_restore(flags); put_cpu(); @@ -1284,7 +1284,7 @@ static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) if (!zlc) return NULL; - if (time_after(jiffies, zlc->last_full_zap + HZ)) { + if (time_after(jiffies, zlc->last_full_zap + HZ)) { bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); zlc->last_full_zap = jiffies; } @@ -1317,7 +1317,7 @@ static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) * We are low on memory in the second scan, and should leave no stone * unturned looking for a free page. */ -static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, +static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, nodemask_t *allowednodes) { struct zonelist_cache *zlc; /* cached zonelist speedup info */ @@ -1328,7 +1328,7 @@ static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, if (!zlc) return 1; - i = z - zonelist->zones; + i = z - zonelist->_zonerefs; n = zlc->z_to_n[i]; /* This zone is worth trying if it is allowed but not full */ @@ -1340,7 +1340,7 @@ static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, * zlc->fullzones, so that subsequent attempts to allocate a page * from that zone don't waste time re-examining it. */ -static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) +static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) { struct zonelist_cache *zlc; /* cached zonelist speedup info */ int i; /* index of *z in zonelist zones */ @@ -1349,7 +1349,7 @@ static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) if (!zlc) return; - i = z - zonelist->zones; + i = z - zonelist->_zonerefs; set_bit(i, zlc->fullzones); } @@ -1361,13 +1361,13 @@ static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) return NULL; } -static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zone **z, +static int zlc_zone_worth_trying(struct zonelist *zonelist, struct zoneref *z, nodemask_t *allowednodes) { return 1; } -static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) +static void zlc_mark_zone_full(struct zonelist *zonelist, struct zoneref *z) { } #endif /* CONFIG_NUMA */ @@ -1377,42 +1377,31 @@ static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) * a page. */ static struct page * -get_page_from_freelist(gfp_t gfp_mask, unsigned int order, - struct zonelist *zonelist, int alloc_flags) +get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, + struct zonelist *zonelist, int high_zoneidx, int alloc_flags) { - struct zone **z; + struct zoneref *z; struct page *page = NULL; - int classzone_idx = zone_idx(zonelist->zones[0]); - struct zone *zone; + int classzone_idx; + struct zone *zone, *preferred_zone; nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */ int zlc_active = 0; /* set if using zonelist_cache */ int did_zlc_setup = 0; /* just call zlc_setup() one time */ - enum zone_type highest_zoneidx = -1; /* Gets set for policy zonelists */ + + (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, + &preferred_zone); + classzone_idx = zone_idx(preferred_zone); zonelist_scan: /* * Scan zonelist, looking for a zone with enough free. * See also cpuset_zone_allowed() comment in kernel/cpuset.c. */ - z = zonelist->zones; - - do { - /* - * In NUMA, this could be a policy zonelist which contains - * zones that may not be allowed by the current gfp_mask. - * Check the zone is allowed by the current flags - */ - if (unlikely(alloc_should_filter_zonelist(zonelist))) { - if (highest_zoneidx == -1) - highest_zoneidx = gfp_zone(gfp_mask); - if (zone_idx(*z) > highest_zoneidx) - continue; - } - + for_each_zone_zonelist_nodemask(zone, z, zonelist, + high_zoneidx, nodemask) { if (NUMA_BUILD && zlc_active && !zlc_zone_worth_trying(zonelist, z, allowednodes)) continue; - zone = *z; if ((alloc_flags & ALLOC_CPUSET) && !cpuset_zone_allowed_softwall(zone, gfp_mask)) goto try_next_zone; @@ -1433,7 +1422,7 @@ zonelist_scan: } } - page = buffered_rmqueue(zonelist, zone, order, gfp_mask); + page = buffered_rmqueue(preferred_zone, zone, order, gfp_mask); if (page) break; this_zone_full: @@ -1446,7 +1435,7 @@ try_next_zone: zlc_active = 1; did_zlc_setup = 1; } - } while (*(++z) != NULL); + } if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) { /* Disable zlc cache for second zonelist scan */ @@ -1459,18 +1448,21 @@ try_next_zone: /* * This is the 'heart' of the zoned buddy allocator. */ -struct page * -__alloc_pages(gfp_t gfp_mask, unsigned int order, - struct zonelist *zonelist) +static struct page * +__alloc_pages_internal(gfp_t gfp_mask, unsigned int order, + struct zonelist *zonelist, nodemask_t *nodemask) { const gfp_t wait = gfp_mask & __GFP_WAIT; - struct zone **z; + enum zone_type high_zoneidx = gfp_zone(gfp_mask); + struct zoneref *z; + struct zone *zone; struct page *page; struct reclaim_state reclaim_state; struct task_struct *p = current; int do_retry; int alloc_flags; - int did_some_progress; + unsigned long did_some_progress; + unsigned long pages_reclaimed = 0; might_sleep_if(wait); @@ -1478,9 +1470,9 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order, return NULL; restart: - z = zonelist->zones; /* the list of zones suitable for gfp_mask */ + z = zonelist->_zonerefs; /* the list of zones suitable for gfp_mask */ - if (unlikely(*z == NULL)) { + if (unlikely(!z->zone)) { /* * Happens if we have an empty zonelist as a result of * GFP_THISNODE being used on a memoryless node @@ -1488,8 +1480,8 @@ restart: return NULL; } - page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET); + page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order, + zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET); if (page) goto got_pg; @@ -1504,8 +1496,8 @@ restart: if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) goto nopage; - for (z = zonelist->zones; *z; z++) - wakeup_kswapd(*z, order); + for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) + wakeup_kswapd(zone, order); /* * OK, we're below the kswapd watermark and have kicked background @@ -1533,7 +1525,8 @@ restart: * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc. * See also cpuset_zone_allowed() comment in kernel/cpuset.c. */ - page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags); + page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, + high_zoneidx, alloc_flags); if (page) goto got_pg; @@ -1545,8 +1538,8 @@ rebalance: if (!(gfp_mask & __GFP_NOMEMALLOC)) { nofail_alloc: /* go through the zonelist yet again, ignoring mins */ - page = get_page_from_freelist(gfp_mask, order, - zonelist, ALLOC_NO_WATERMARKS); + page = get_page_from_freelist(gfp_mask, nodemask, order, + zonelist, high_zoneidx, ALLOC_NO_WATERMARKS); if (page) goto got_pg; if (gfp_mask & __GFP_NOFAIL) { @@ -1569,7 +1562,7 @@ nofail_alloc: reclaim_state.reclaimed_slab = 0; p->reclaim_state = &reclaim_state; - did_some_progress = try_to_free_pages(zonelist->zones, order, gfp_mask); + did_some_progress = try_to_free_pages(zonelist, order, gfp_mask); p->reclaim_state = NULL; p->flags &= ~PF_MEMALLOC; @@ -1580,12 +1573,12 @@ nofail_alloc: drain_all_pages(); if (likely(did_some_progress)) { - page = get_page_from_freelist(gfp_mask, order, - zonelist, alloc_flags); + page = get_page_from_freelist(gfp_mask, nodemask, order, + zonelist, high_zoneidx, alloc_flags); if (page) goto got_pg; } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) { - if (!try_set_zone_oom(zonelist)) { + if (!try_set_zone_oom(zonelist, gfp_mask)) { schedule_timeout_uninterruptible(1); goto restart; } @@ -1596,21 +1589,22 @@ nofail_alloc: * a parallel oom killing, we must fail if we're still * under heavy pressure. */ - page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order, - zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET); + page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, + order, zonelist, high_zoneidx, + ALLOC_WMARK_HIGH|ALLOC_CPUSET); if (page) { - clear_zonelist_oom(zonelist); + clear_zonelist_oom(zonelist, gfp_mask); goto got_pg; } /* The OOM killer will not help higher order allocs so fail */ if (order > PAGE_ALLOC_COSTLY_ORDER) { - clear_zonelist_oom(zonelist); + clear_zonelist_oom(zonelist, gfp_mask); goto nopage; } out_of_memory(zonelist, gfp_mask, order); - clear_zonelist_oom(zonelist); + clear_zonelist_oom(zonelist, gfp_mask); goto restart; } @@ -1618,14 +1612,26 @@ nofail_alloc: * Don't let big-order allocations loop unless the caller explicitly * requests that. Wait for some write requests to complete then retry. * - * In this implementation, __GFP_REPEAT means __GFP_NOFAIL for order - * <= 3, but that may not be true in other implementations. + * In this implementation, order <= PAGE_ALLOC_COSTLY_ORDER + * means __GFP_NOFAIL, but that may not be true in other + * implementations. + * + * For order > PAGE_ALLOC_COSTLY_ORDER, if __GFP_REPEAT is + * specified, then we retry until we no longer reclaim any pages + * (above), or we've reclaimed an order of pages at least as + * large as the allocation's order. In both cases, if the + * allocation still fails, we stop retrying. */ + pages_reclaimed += did_some_progress; do_retry = 0; if (!(gfp_mask & __GFP_NORETRY)) { - if ((order <= PAGE_ALLOC_COSTLY_ORDER) || - (gfp_mask & __GFP_REPEAT)) + if (order <= PAGE_ALLOC_COSTLY_ORDER) { do_retry = 1; + } else { + if (gfp_mask & __GFP_REPEAT && + pages_reclaimed < (1 << order)) + do_retry = 1; + } if (gfp_mask & __GFP_NOFAIL) do_retry = 1; } @@ -1646,6 +1652,20 @@ got_pg: return page; } +struct page * +__alloc_pages(gfp_t gfp_mask, unsigned int order, + struct zonelist *zonelist) +{ + return __alloc_pages_internal(gfp_mask, order, zonelist, NULL); +} + +struct page * +__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, + struct zonelist *zonelist, nodemask_t *nodemask) +{ + return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask); +} + EXPORT_SYMBOL(__alloc_pages); /* @@ -1712,15 +1732,15 @@ EXPORT_SYMBOL(free_pages); static unsigned int nr_free_zone_pages(int offset) { + struct zoneref *z; + struct zone *zone; + /* Just pick one node, since fallback list is circular */ - pg_data_t *pgdat = NODE_DATA(numa_node_id()); unsigned int sum = 0; - struct zonelist *zonelist = pgdat->node_zonelists + offset; - struct zone **zonep = zonelist->zones; - struct zone *zone; + struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL); - for (zone = *zonep++; zone; zone = *zonep++) { + for_each_zone_zonelist(zone, z, zonelist, offset) { unsigned long size = zone->present_pages; unsigned long high = zone->pages_high; if (size > high) @@ -1889,6 +1909,12 @@ void show_free_areas(void) show_swap_cache_info(); } +static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref) +{ + zoneref->zone = zone; + zoneref->zone_idx = zone_idx(zone); +} + /* * Builds allocation fallback zone lists. * @@ -1906,7 +1932,8 @@ static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist, zone_type--; zone = pgdat->node_zones + zone_type; if (populated_zone(zone)) { - zonelist->zones[nr_zones++] = zone; + zoneref_set_zone(zone, + &zonelist->_zonerefs[nr_zones++]); check_highest_zone(zone_type); } @@ -2078,17 +2105,16 @@ static int find_next_best_node(int node, nodemask_t *used_node_mask) */ static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) { - enum zone_type i; int j; struct zonelist *zonelist; - for (i = 0; i < MAX_NR_ZONES; i++) { - zonelist = pgdat->node_zonelists + i; - for (j = 0; zonelist->zones[j] != NULL; j++) - ; - j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); - zonelist->zones[j] = NULL; - } + zonelist = &pgdat->node_zonelists[0]; + for (j = 0; zonelist->_zonerefs[j].zone != NULL; j++) + ; + j = build_zonelists_node(NODE_DATA(node), zonelist, j, + MAX_NR_ZONES - 1); + zonelist->_zonerefs[j].zone = NULL; + zonelist->_zonerefs[j].zone_idx = 0; } /* @@ -2096,15 +2122,13 @@ static void build_zonelists_in_node_order(pg_data_t *pgdat, int node) */ static void build_thisnode_zonelists(pg_data_t *pgdat) { - enum zone_type i; int j; struct zonelist *zonelist; - for (i = 0; i < MAX_NR_ZONES; i++) { - zonelist = pgdat->node_zonelists + MAX_NR_ZONES + i; - j = build_zonelists_node(pgdat, zonelist, 0, i); - zonelist->zones[j] = NULL; - } + zonelist = &pgdat->node_zonelists[1]; + j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); + zonelist->_zonerefs[j].zone = NULL; + zonelist->_zonerefs[j].zone_idx = 0; } /* @@ -2117,27 +2141,26 @@ static int node_order[MAX_NUMNODES]; static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes) { - enum zone_type i; int pos, j, node; int zone_type; /* needs to be signed */ struct zone *z; struct zonelist *zonelist; - for (i = 0; i < MAX_NR_ZONES; i++) { - zonelist = pgdat->node_zonelists + i; - pos = 0; - for (zone_type = i; zone_type >= 0; zone_type--) { - for (j = 0; j < nr_nodes; j++) { - node = node_order[j]; - z = &NODE_DATA(node)->node_zones[zone_type]; - if (populated_zone(z)) { - zonelist->zones[pos++] = z; - check_highest_zone(zone_type); - } + zonelist = &pgdat->node_zonelists[0]; + pos = 0; + for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) { + for (j = 0; j < nr_nodes; j++) { + node = node_order[j]; + z = &NODE_DATA(node)->node_zones[zone_type]; + if (populated_zone(z)) { + zoneref_set_zone(z, + &zonelist->_zonerefs[pos++]); + check_highest_zone(zone_type); } } - zonelist->zones[pos] = NULL; } + zonelist->_zonerefs[pos].zone = NULL; + zonelist->_zonerefs[pos].zone_idx = 0; } static int default_zonelist_order(void) @@ -2214,7 +2237,8 @@ static void build_zonelists(pg_data_t *pgdat) /* initialize zonelists */ for (i = 0; i < MAX_ZONELISTS; i++) { zonelist = pgdat->node_zonelists + i; - zonelist->zones[0] = NULL; + zonelist->_zonerefs[0].zone = NULL; + zonelist->_zonerefs[0].zone_idx = 0; } /* NUMA-aware ordering of nodes */ @@ -2264,19 +2288,15 @@ static void build_zonelists(pg_data_t *pgdat) /* Construct the zonelist performance cache - see further mmzone.h */ static void build_zonelist_cache(pg_data_t *pgdat) { - int i; - - for (i = 0; i < MAX_NR_ZONES; i++) { - struct zonelist *zonelist; - struct zonelist_cache *zlc; - struct zone **z; + struct zonelist *zonelist; + struct zonelist_cache *zlc; + struct zoneref *z; - zonelist = pgdat->node_zonelists + i; - zonelist->zlcache_ptr = zlc = &zonelist->zlcache; - bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); - for (z = zonelist->zones; *z; z++) - zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z); - } + zonelist = &pgdat->node_zonelists[0]; + zonelist->zlcache_ptr = zlc = &zonelist->zlcache; + bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); + for (z = zonelist->_zonerefs; z->zone; z++) + zlc->z_to_n[z - zonelist->_zonerefs] = zonelist_node_idx(z); } @@ -2290,45 +2310,44 @@ static void set_zonelist_order(void) static void build_zonelists(pg_data_t *pgdat) { int node, local_node; - enum zone_type i,j; + enum zone_type j; + struct zonelist *zonelist; local_node = pgdat->node_id; - for (i = 0; i < MAX_NR_ZONES; i++) { - struct zonelist *zonelist; - zonelist = pgdat->node_zonelists + i; + zonelist = &pgdat->node_zonelists[0]; + j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1); - j = build_zonelists_node(pgdat, zonelist, 0, i); - /* - * Now we build the zonelist so that it contains the zones - * of all the other nodes. - * We don't want to pressure a particular node, so when - * building the zones for node N, we make sure that the - * zones coming right after the local ones are those from - * node N+1 (modulo N) - */ - for (node = local_node + 1; node < MAX_NUMNODES; node++) { - if (!node_online(node)) - continue; - j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); - } - for (node = 0; node < local_node; node++) { - if (!node_online(node)) - continue; - j = build_zonelists_node(NODE_DATA(node), zonelist, j, i); - } - - zonelist->zones[j] = NULL; + /* + * Now we build the zonelist so that it contains the zones + * of all the other nodes. + * We don't want to pressure a particular node, so when + * building the zones for node N, we make sure that the + * zones coming right after the local ones are those from + * node N+1 (modulo N) + */ + for (node = local_node + 1; node < MAX_NUMNODES; node++) { + if (!node_online(node)) + continue; + j = build_zonelists_node(NODE_DATA(node), zonelist, j, + MAX_NR_ZONES - 1); } + for (node = 0; node < local_node; node++) { + if (!node_online(node)) + continue; + j = build_zonelists_node(NODE_DATA(node), zonelist, j, + MAX_NR_ZONES - 1); + } + + zonelist->_zonerefs[j].zone = NULL; + zonelist->_zonerefs[j].zone_idx = 0; } /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ static void build_zonelist_cache(pg_data_t *pgdat) { - int i; - - for (i = 0; i < MAX_NR_ZONES; i++) - pgdat->node_zonelists[i].zlcache_ptr = NULL; + pgdat->node_zonelists[0].zlcache_ptr = NULL; + pgdat->node_zonelists[1].zlcache_ptr = NULL; } #endif /* CONFIG_NUMA */ @@ -2518,7 +2537,9 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, struct page *page; unsigned long end_pfn = start_pfn + size; unsigned long pfn; + struct zone *z; + z = &NODE_DATA(nid)->node_zones[zone]; for (pfn = start_pfn; pfn < end_pfn; pfn++) { /* * There can be holes in boot-time mem_map[]s @@ -2536,7 +2557,6 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, init_page_count(page); reset_page_mapcount(page); SetPageReserved(page); - /* * Mark the block movable so that blocks are reserved for * movable at startup. This will force kernel allocations @@ -2545,8 +2565,15 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, * kernel allocations are made. Later some blocks near * the start are marked MIGRATE_RESERVE by * setup_zone_migrate_reserve() + * + * bitmap is created for zone's valid pfn range. but memmap + * can be created for invalid pages (for alignment) + * check here not to call set_pageblock_migratetype() against + * pfn out of zone. */ - if ((pfn & (pageblock_nr_pages-1))) + if ((z->zone_start_pfn <= pfn) + && (pfn < z->zone_start_pfn + z->spanned_pages) + && !(pfn & (pageblock_nr_pages - 1))) set_pageblock_migratetype(page, MIGRATE_MOVABLE); INIT_LIST_HEAD(&page->lru); @@ -4339,9 +4366,7 @@ void *__init alloc_large_system_hash(const char *tablename, else if (hashdist) table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL); else { - unsigned long order; - for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++) - ; + unsigned long order = get_order(size); table = (void*) __get_free_pages(GFP_ATOMIC, order); /* * If bucketsize is not a power-of-two, we may free @@ -4460,6 +4485,8 @@ void set_pageblock_flags_group(struct page *page, unsigned long flags, pfn = page_to_pfn(page); bitmap = get_pageblock_bitmap(zone, pfn); bitidx = pfn_to_bitidx(zone, pfn); + VM_BUG_ON(pfn < zone->zone_start_pfn); + VM_BUG_ON(pfn >= zone->zone_start_pfn + zone->spanned_pages); for (; start_bitidx <= end_bitidx; start_bitidx++, value <<= 1) if (flags & value) |