diff options
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r-- | mm/page_alloc.c | 281 |
1 files changed, 224 insertions, 57 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index aa6fcc7ca66..cace22b3ac2 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -83,14 +83,7 @@ int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = { EXPORT_SYMBOL(totalram_pages); -/* - * Used by page_zone() to look up the address of the struct zone whose - * id is encoded in the upper bits of page->flags - */ -struct zone *zone_table[1 << ZONETABLE_SHIFT] __read_mostly; -EXPORT_SYMBOL(zone_table); - -static char *zone_names[MAX_NR_ZONES] = { +static char * const zone_names[MAX_NR_ZONES] = { "DMA", #ifdef CONFIG_ZONE_DMA32 "DMA32", @@ -237,7 +230,7 @@ static void prep_compound_page(struct page *page, unsigned long order) int i; int nr_pages = 1 << order; - page[1].lru.next = (void *)free_compound_page; /* set dtor */ + set_compound_page_dtor(page, free_compound_page); page[1].lru.prev = (void *)order; for (i = 0; i < nr_pages; i++) { struct page *p = page + i; @@ -486,7 +479,7 @@ static void free_one_page(struct zone *zone, struct page *page, int order) spin_lock(&zone->lock); zone->all_unreclaimable = 0; zone->pages_scanned = 0; - __free_one_page(page, zone ,order); + __free_one_page(page, zone, order); spin_unlock(&zone->lock); } @@ -605,6 +598,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 1 << PG_checked | 1 << PG_mappedtodisk); set_page_private(page, 0); set_page_refcounted(page); + + arch_alloc_page(page, order); kernel_map_pages(page, 1 << order, 1); if (gfp_flags & __GFP_ZERO) @@ -690,9 +685,15 @@ void drain_node_pages(int nodeid) pcp = &pset->pcp[i]; if (pcp->count) { + int to_drain; + local_irq_save(flags); - free_pages_bulk(zone, pcp->count, &pcp->list, 0); - pcp->count = 0; + if (pcp->count >= pcp->batch) + to_drain = pcp->batch; + else + to_drain = pcp->count; + free_pages_bulk(zone, to_drain, &pcp->list, 0); + pcp->count -= to_drain; local_irq_restore(flags); } } @@ -700,7 +701,6 @@ void drain_node_pages(int nodeid) } #endif -#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) static void __drain_pages(unsigned int cpu) { unsigned long flags; @@ -722,7 +722,6 @@ static void __drain_pages(unsigned int cpu) } } } -#endif /* CONFIG_PM || CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_PM @@ -925,31 +924,160 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark, return 1; } +#ifdef CONFIG_NUMA +/* + * zlc_setup - Setup for "zonelist cache". Uses cached zone data to + * skip over zones that are not allowed by the cpuset, or that have + * been recently (in last second) found to be nearly full. See further + * comments in mmzone.h. Reduces cache footprint of zonelist scans + * that have to skip over alot of full or unallowed zones. + * + * If the zonelist cache is present in the passed in zonelist, then + * returns a pointer to the allowed node mask (either the current + * tasks mems_allowed, or node_online_map.) + * + * If the zonelist cache is not available for this zonelist, does + * nothing and returns NULL. + * + * If the fullzones BITMAP in the zonelist cache is stale (more than + * a second since last zap'd) then we zap it out (clear its bits.) + * + * We hold off even calling zlc_setup, until after we've checked the + * first zone in the zonelist, on the theory that most allocations will + * be satisfied from that first zone, so best to examine that zone as + * quickly as we can. + */ +static nodemask_t *zlc_setup(struct zonelist *zonelist, int alloc_flags) +{ + struct zonelist_cache *zlc; /* cached zonelist speedup info */ + nodemask_t *allowednodes; /* zonelist_cache approximation */ + + zlc = zonelist->zlcache_ptr; + if (!zlc) + return NULL; + + if (jiffies - zlc->last_full_zap > 1 * HZ) { + bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST); + zlc->last_full_zap = jiffies; + } + + allowednodes = !in_interrupt() && (alloc_flags & ALLOC_CPUSET) ? + &cpuset_current_mems_allowed : + &node_online_map; + return allowednodes; +} + +/* + * Given 'z' scanning a zonelist, run a couple of quick checks to see + * if it is worth looking at further for free memory: + * 1) Check that the zone isn't thought to be full (doesn't have its + * bit set in the zonelist_cache fullzones BITMAP). + * 2) Check that the zones node (obtained from the zonelist_cache + * z_to_n[] mapping) is allowed in the passed in allowednodes mask. + * Return true (non-zero) if zone is worth looking at further, or + * else return false (zero) if it is not. + * + * This check -ignores- the distinction between various watermarks, + * such as GFP_HIGH, GFP_ATOMIC, PF_MEMALLOC, ... If a zone is + * found to be full for any variation of these watermarks, it will + * be considered full for up to one second by all requests, unless + * we are so low on memory on all allowed nodes that we are forced + * into the second scan of the zonelist. + * + * In the second scan we ignore this zonelist cache and exactly + * apply the watermarks to all zones, even it is slower to do so. + * 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, + nodemask_t *allowednodes) +{ + struct zonelist_cache *zlc; /* cached zonelist speedup info */ + int i; /* index of *z in zonelist zones */ + int n; /* node that zone *z is on */ + + zlc = zonelist->zlcache_ptr; + if (!zlc) + return 1; + + i = z - zonelist->zones; + n = zlc->z_to_n[i]; + + /* This zone is worth trying if it is allowed but not full */ + return node_isset(n, *allowednodes) && !test_bit(i, zlc->fullzones); +} + /* - * get_page_from_freeliest goes through the zonelist trying to allocate + * Given 'z' scanning a zonelist, set the corresponding bit in + * 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) +{ + struct zonelist_cache *zlc; /* cached zonelist speedup info */ + int i; /* index of *z in zonelist zones */ + + zlc = zonelist->zlcache_ptr; + if (!zlc) + return; + + i = z - zonelist->zones; + + set_bit(i, zlc->fullzones); +} + +#else /* CONFIG_NUMA */ + +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, + nodemask_t *allowednodes) +{ + return 1; +} + +static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z) +{ +} +#endif /* CONFIG_NUMA */ + +/* + * get_page_from_freelist goes through the zonelist trying to allocate * a page. */ static struct page * get_page_from_freelist(gfp_t gfp_mask, unsigned int order, struct zonelist *zonelist, int alloc_flags) { - struct zone **z = zonelist->zones; + struct zone **z; struct page *page = NULL; - int classzone_idx = zone_idx(*z); + int classzone_idx = zone_idx(zonelist->zones[0]); struct zone *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 */ +zonelist_scan: /* - * Go through the zonelist once, looking for a zone with enough free. + * Scan zonelist, looking for a zone with enough free. * See also cpuset_zone_allowed() comment in kernel/cpuset.c. */ + z = zonelist->zones; + do { + if (NUMA_BUILD && zlc_active && + !zlc_zone_worth_trying(zonelist, z, allowednodes)) + continue; zone = *z; if (unlikely(NUMA_BUILD && (gfp_mask & __GFP_THISNODE) && zone->zone_pgdat != zonelist->zones[0]->zone_pgdat)) break; if ((alloc_flags & ALLOC_CPUSET) && - !cpuset_zone_allowed(zone, gfp_mask)) - continue; + !cpuset_zone_allowed(zone, gfp_mask)) + goto try_next_zone; if (!(alloc_flags & ALLOC_NO_WATERMARKS)) { unsigned long mark; @@ -959,18 +1087,34 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, mark = zone->pages_low; else mark = zone->pages_high; - if (!zone_watermark_ok(zone , order, mark, - classzone_idx, alloc_flags)) + if (!zone_watermark_ok(zone, order, mark, + classzone_idx, alloc_flags)) { if (!zone_reclaim_mode || !zone_reclaim(zone, gfp_mask, order)) - continue; + goto this_zone_full; + } } page = buffered_rmqueue(zonelist, zone, order, gfp_mask); - if (page) { + if (page) break; +this_zone_full: + if (NUMA_BUILD) + zlc_mark_zone_full(zonelist, z); +try_next_zone: + if (NUMA_BUILD && !did_zlc_setup) { + /* we do zlc_setup after the first zone is tried */ + allowednodes = zlc_setup(zonelist, alloc_flags); + 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 */ + zlc_active = 0; + goto zonelist_scan; + } return page; } @@ -1005,9 +1149,19 @@ restart: if (page) goto got_pg; - do { + /* + * GFP_THISNODE (meaning __GFP_THISNODE, __GFP_NORETRY and + * __GFP_NOWARN set) should not cause reclaim since the subsystem + * (f.e. slab) using GFP_THISNODE may choose to trigger reclaim + * using a larger set of nodes after it has established that the + * allowed per node queues are empty and that nodes are + * over allocated. + */ + if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) + goto nopage; + + for (z = zonelist->zones; *z; z++) wakeup_kswapd(*z, order); - } while (*(++z)); /* * OK, we're below the kswapd watermark and have kicked background @@ -1041,6 +1195,7 @@ restart: /* This allocation should allow future memory freeing. */ +rebalance: if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE))) && !in_interrupt()) { if (!(gfp_mask & __GFP_NOMEMALLOC)) { @@ -1062,7 +1217,6 @@ nofail_alloc: if (!wait) goto nopage; -rebalance: cond_resched(); /* We now go into synchronous reclaim */ @@ -1262,7 +1416,7 @@ unsigned int nr_free_pagecache_pages(void) static inline void show_node(struct zone *zone) { if (NUMA_BUILD) - printk("Node %ld ", zone_to_nid(zone)); + printk("Node %d ", zone_to_nid(zone)); } void si_meminfo(struct sysinfo *val) @@ -1542,6 +1696,24 @@ static void __meminit build_zonelists(pg_data_t *pgdat) } } +/* Construct the zonelist performance cache - see further mmzone.h */ +static void __meminit 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; + + 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); + } +} + #else /* CONFIG_NUMA */ static void __meminit build_zonelists(pg_data_t *pgdat) @@ -1579,14 +1751,26 @@ static void __meminit build_zonelists(pg_data_t *pgdat) } } +/* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */ +static void __meminit build_zonelist_cache(pg_data_t *pgdat) +{ + int i; + + for (i = 0; i < MAX_NR_ZONES; i++) + pgdat->node_zonelists[i].zlcache_ptr = NULL; +} + #endif /* CONFIG_NUMA */ /* return values int ....just for stop_machine_run() */ static int __meminit __build_all_zonelists(void *dummy) { int nid; - for_each_online_node(nid) + + for_each_online_node(nid) { build_zonelists(NODE_DATA(nid)); + build_zonelist_cache(NODE_DATA(nid)); + } return 0; } @@ -1715,20 +1899,6 @@ void zone_init_free_lists(struct pglist_data *pgdat, struct zone *zone, } } -#define ZONETABLE_INDEX(x, zone_nr) ((x << ZONES_SHIFT) | zone_nr) -void zonetable_add(struct zone *zone, int nid, enum zone_type zid, - unsigned long pfn, unsigned long size) -{ - unsigned long snum = pfn_to_section_nr(pfn); - unsigned long end = pfn_to_section_nr(pfn + size); - - if (FLAGS_HAS_NODE) - zone_table[ZONETABLE_INDEX(nid, zid)] = zone; - else - for (; snum <= end; snum++) - zone_table[ZONETABLE_INDEX(snum, zid)] = zone; -} - #ifndef __HAVE_ARCH_MEMMAP_INIT #define memmap_init(size, nid, zone, start_pfn) \ memmap_init_zone((size), (nid), (zone), (start_pfn)) @@ -1881,16 +2051,16 @@ static int __cpuinit pageset_cpuup_callback(struct notifier_block *nfb, int ret = NOTIFY_OK; switch (action) { - case CPU_UP_PREPARE: - if (process_zones(cpu)) - ret = NOTIFY_BAD; - break; - case CPU_UP_CANCELED: - case CPU_DEAD: - free_zone_pagesets(cpu); - break; - default: - break; + case CPU_UP_PREPARE: + if (process_zones(cpu)) + ret = NOTIFY_BAD; + break; + case CPU_UP_CANCELED: + case CPU_DEAD: + free_zone_pagesets(cpu); + break; + default: + break; } return ret; } @@ -2421,7 +2591,6 @@ static void __meminit free_area_init_core(struct pglist_data *pgdat, if (!size) continue; - zonetable_add(zone, nid, j, zone_start_pfn, size); ret = init_currently_empty_zone(zone, zone_start_pfn, size); BUG_ON(ret); zone_start_pfn += size; @@ -2736,7 +2905,6 @@ void __init free_area_init(unsigned long *zones_size) __pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL); } -#ifdef CONFIG_HOTPLUG_CPU static int page_alloc_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { @@ -2751,7 +2919,6 @@ static int page_alloc_cpu_notify(struct notifier_block *self, } return NOTIFY_OK; } -#endif /* CONFIG_HOTPLUG_CPU */ void __init page_alloc_init(void) { @@ -3055,7 +3222,7 @@ void *__init alloc_large_system_hash(const char *tablename, /* allow the kernel cmdline to have a say */ if (!numentries) { /* round applicable memory size up to nearest megabyte */ - numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages; + numentries = nr_kernel_pages; numentries += (1UL << (20 - PAGE_SHIFT)) - 1; numentries >>= 20 - PAGE_SHIFT; numentries <<= 20 - PAGE_SHIFT; |