diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 175 |
1 files changed, 145 insertions, 30 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index bd65b60939b6..9327a940e373 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -66,6 +66,8 @@ #include <linux/kthread.h> #include <linux/memcontrol.h> #include <linux/ftrace.h> +#include <linux/lockdep.h> +#include <linux/nmi.h> #include <asm/sections.h> #include <asm/tlbflush.h> @@ -1584,6 +1586,10 @@ void __init page_alloc_init_late(void) /* Reinit limits that are based on free pages after the kernel is up */ files_maxfiles_init(); #endif +#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK + /* Discard memblock private memory */ + memblock_discard(); +#endif for_each_populated_zone(zone) set_zone_contiguous(zone); @@ -2206,19 +2212,26 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, * list of requested migratetype, possibly along with other pages from the same * block, depending on fragmentation avoidance heuristics. Returns true if * fallback was found so that __rmqueue_smallest() can grab it. + * + * The use of signed ints for order and current_order is a deliberate + * deviation from the rest of this file, to make the for loop + * condition simpler. */ static inline bool -__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) +__rmqueue_fallback(struct zone *zone, int order, int start_migratetype) { struct free_area *area; - unsigned int current_order; + int current_order; struct page *page; int fallback_mt; bool can_steal; - /* Find the largest possible block of pages in the other list */ - for (current_order = MAX_ORDER-1; - current_order >= order && current_order <= MAX_ORDER-1; + /* + * Find the largest available free page in the other list. This roughly + * approximates finding the pageblock with the most free pages, which + * would be too costly to do exactly. + */ + for (current_order = MAX_ORDER - 1; current_order >= order; --current_order) { area = &(zone->free_area[current_order]); fallback_mt = find_suitable_fallback(area, current_order, @@ -2226,19 +2239,50 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) if (fallback_mt == -1) continue; - page = list_first_entry(&area->free_list[fallback_mt], - struct page, lru); + /* + * We cannot steal all free pages from the pageblock and the + * requested migratetype is movable. In that case it's better to + * steal and split the smallest available page instead of the + * largest available page, because even if the next movable + * allocation falls back into a different pageblock than this + * one, it won't cause permanent fragmentation. + */ + if (!can_steal && start_migratetype == MIGRATE_MOVABLE + && current_order > order) + goto find_smallest; - steal_suitable_fallback(zone, page, start_migratetype, - can_steal); + goto do_steal; + } - trace_mm_page_alloc_extfrag(page, order, current_order, - start_migratetype, fallback_mt); + return false; - return true; +find_smallest: + for (current_order = order; current_order < MAX_ORDER; + current_order++) { + area = &(zone->free_area[current_order]); + fallback_mt = find_suitable_fallback(area, current_order, + start_migratetype, false, &can_steal); + if (fallback_mt != -1) + break; } - return false; + /* + * This should not happen - we already found a suitable fallback + * when looking for the largest page. + */ + VM_BUG_ON(current_order == MAX_ORDER); + +do_steal: + page = list_first_entry(&area->free_list[fallback_mt], + struct page, lru); + + steal_suitable_fallback(zone, page, start_migratetype, can_steal); + + trace_mm_page_alloc_extfrag(page, order, current_order, + start_migratetype, fallback_mt); + + return true; + } /* @@ -2493,9 +2537,14 @@ void drain_all_pages(struct zone *zone) #ifdef CONFIG_HIBERNATION +/* + * Touch the watchdog for every WD_PAGE_COUNT pages. + */ +#define WD_PAGE_COUNT (128*1024) + void mark_free_pages(struct zone *zone) { - unsigned long pfn, max_zone_pfn; + unsigned long pfn, max_zone_pfn, page_count = WD_PAGE_COUNT; unsigned long flags; unsigned int order, t; struct page *page; @@ -2510,6 +2559,11 @@ void mark_free_pages(struct zone *zone) if (pfn_valid(pfn)) { page = pfn_to_page(pfn); + if (!--page_count) { + touch_nmi_watchdog(); + page_count = WD_PAGE_COUNT; + } + if (page_zone(page) != zone) continue; @@ -2523,8 +2577,13 @@ void mark_free_pages(struct zone *zone) unsigned long i; pfn = page_to_pfn(page); - for (i = 0; i < (1UL << order); i++) + for (i = 0; i < (1UL << order); i++) { + if (!--page_count) { + touch_nmi_watchdog(); + page_count = WD_PAGE_COUNT; + } swsusp_set_page_free(pfn_to_page(pfn + i)); + } } } spin_unlock_irqrestore(&zone->lock, flags); @@ -3233,10 +3292,13 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, /* * Go through the zonelist yet one more time, keep very high watermark * here, this is only to catch a parallel oom killing, we must fail if - * we're still under heavy pressure. + * we're still under heavy pressure. But make sure that this reclaim + * attempt shall not depend on __GFP_DIRECT_RECLAIM && !__GFP_NORETRY + * allocation which will never fail due to oom_lock already held. */ - page = get_page_from_freelist(gfp_mask | __GFP_HARDWALL, order, - ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); + page = get_page_from_freelist((gfp_mask | __GFP_HARDWALL) & + ~__GFP_DIRECT_RECLAIM, order, + ALLOC_WMARK_HIGH|ALLOC_CPUSET, ac); if (page) goto out; @@ -3246,6 +3308,14 @@ __alloc_pages_may_oom(gfp_t gfp_mask, unsigned int order, /* The OOM killer will not help higher order allocs */ if (order > PAGE_ALLOC_COSTLY_ORDER) goto out; + /* + * We have already exhausted all our reclaim opportunities without any + * success so it is time to admit defeat. We will skip the OOM killer + * because it is very likely that the caller has a more reasonable + * fallback than shooting a random task. + */ + if (gfp_mask & __GFP_RETRY_MAYFAIL) + goto out; /* The OOM killer does not needlessly kill tasks for lowmem */ if (ac->high_zoneidx < ZONE_NORMAL) goto out; @@ -3375,7 +3445,7 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, } /* - * !costly requests are much more important than __GFP_REPEAT + * !costly requests are much more important than __GFP_RETRY_MAYFAIL * costly ones because they are de facto nofail and invoke OOM * killer to move on while costly can fail and users are ready * to cope with that. 1/4 retries is rather arbitrary but we @@ -3444,6 +3514,47 @@ should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_fla } #endif /* CONFIG_COMPACTION */ +#ifdef CONFIG_LOCKDEP +struct lockdep_map __fs_reclaim_map = + STATIC_LOCKDEP_MAP_INIT("fs_reclaim", &__fs_reclaim_map); + +static bool __need_fs_reclaim(gfp_t gfp_mask) +{ + gfp_mask = current_gfp_context(gfp_mask); + + /* no reclaim without waiting on it */ + if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) + return false; + + /* this guy won't enter reclaim */ + if ((current->flags & PF_MEMALLOC) && !(gfp_mask & __GFP_NOMEMALLOC)) + return false; + + /* We're only interested __GFP_FS allocations for now */ + if (!(gfp_mask & __GFP_FS)) + return false; + + if (gfp_mask & __GFP_NOLOCKDEP) + return false; + + return true; +} + +void fs_reclaim_acquire(gfp_t gfp_mask) +{ + if (__need_fs_reclaim(gfp_mask)) + lock_map_acquire(&__fs_reclaim_map); +} +EXPORT_SYMBOL_GPL(fs_reclaim_acquire); + +void fs_reclaim_release(gfp_t gfp_mask) +{ + if (__need_fs_reclaim(gfp_mask)) + lock_map_release(&__fs_reclaim_map); +} +EXPORT_SYMBOL_GPL(fs_reclaim_release); +#endif + /* Perform direct synchronous page reclaim */ static int __perform_reclaim(gfp_t gfp_mask, unsigned int order, @@ -3458,7 +3569,7 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order, /* We now go into synchronous reclaim */ cpuset_memory_pressure_bump(); noreclaim_flag = memalloc_noreclaim_save(); - lockdep_set_current_reclaim_state(gfp_mask); + fs_reclaim_acquire(gfp_mask); reclaim_state.reclaimed_slab = 0; current->reclaim_state = &reclaim_state; @@ -3466,7 +3577,7 @@ __perform_reclaim(gfp_t gfp_mask, unsigned int order, ac->nodemask); current->reclaim_state = NULL; - lockdep_clear_current_reclaim_state(); + fs_reclaim_release(gfp_mask); memalloc_noreclaim_restore(noreclaim_flag); cond_resched(); @@ -3882,9 +3993,9 @@ retry: /* * Do not retry costly high order allocations unless they are - * __GFP_REPEAT + * __GFP_RETRY_MAYFAIL */ - if (costly_order && !(gfp_mask & __GFP_REPEAT)) + if (costly_order && !(gfp_mask & __GFP_RETRY_MAYFAIL)) goto nopage; if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, @@ -3995,7 +4106,8 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, *alloc_flags |= ALLOC_CPUSET; } - lockdep_trace_alloc(gfp_mask); + fs_reclaim_acquire(gfp_mask); + fs_reclaim_release(gfp_mask); might_sleep_if(gfp_mask & __GFP_DIRECT_RECLAIM); @@ -4412,8 +4524,9 @@ long si_mem_available(void) * Part of the reclaimable slab consists of items that are in use, * and cannot be freed. Cap this estimate at the low watermark. */ - available += global_page_state(NR_SLAB_RECLAIMABLE) - - min(global_page_state(NR_SLAB_RECLAIMABLE) / 2, wmark_low); + available += global_node_page_state(NR_SLAB_RECLAIMABLE) - + min(global_node_page_state(NR_SLAB_RECLAIMABLE) / 2, + wmark_low); if (available < 0) available = 0; @@ -4556,8 +4669,8 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask) global_node_page_state(NR_FILE_DIRTY), global_node_page_state(NR_WRITEBACK), global_node_page_state(NR_UNSTABLE_NFS), - global_page_state(NR_SLAB_RECLAIMABLE), - global_page_state(NR_SLAB_UNRECLAIMABLE), + global_node_page_state(NR_SLAB_RECLAIMABLE), + global_node_page_state(NR_SLAB_UNRECLAIMABLE), global_node_page_state(NR_FILE_MAPPED), global_node_page_state(NR_SHMEM), global_page_state(NR_PAGETABLE), @@ -4845,9 +4958,11 @@ int numa_zonelist_order_handler(struct ctl_table *table, int write, NUMA_ZONELIST_ORDER_LEN); user_zonelist_order = oldval; } else if (oldval != user_zonelist_order) { + mem_hotplug_begin(); mutex_lock(&zonelists_mutex); build_all_zonelists(NULL, NULL); mutex_unlock(&zonelists_mutex); + mem_hotplug_done(); } } out: @@ -5240,7 +5355,7 @@ void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone) #endif /* we have to stop all cpus to guarantee there is no user of zonelist */ - stop_machine(__build_all_zonelists, pgdat, NULL); + stop_machine_cpuslocked(__build_all_zonelists, pgdat, NULL); /* cpuset refresh routine should be here */ } vm_total_pages = nr_free_pagecache_pages(); @@ -7620,7 +7735,7 @@ int alloc_contig_range(unsigned long start, unsigned long end, /* Make sure the range is really isolated. */ if (test_pages_isolated(outer_start, end, false)) { - pr_info("%s: [%lx, %lx) PFNs busy\n", + pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n", __func__, outer_start, end); ret = -EBUSY; goto done; |