X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=mm%2Fpage_alloc.c;h=f8f3bfc435eec5bf0144798f6b890e6deacee0f6;hb=19599304625b74c95bff318c735928eec668b1ca;hp=5c469c1dfb8bd420c9c0b353cfb24f74a374afa4;hpb=2f37dd131c5d3a2eac21cd5baf80658b1b02a8ac;p=deliverable%2Flinux.git diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 5c469c1dfb8b..f8f3bfc435ee 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -522,12 +522,6 @@ static void bad_page(struct page *page, const char *reason, static unsigned long nr_shown; static unsigned long nr_unshown; - /* Don't complain about poisoned pages */ - if (PageHWPoison(page)) { - page_mapcount_reset(page); /* remove PageBuddy */ - return; - } - /* * Allow a burst of 60 reports, then keep quiet for that minute; * or allow a steady drip of one report per second. @@ -613,14 +607,7 @@ static int __init early_debug_pagealloc(char *buf) { if (!buf) return -EINVAL; - - if (strcmp(buf, "on") == 0) - _debug_pagealloc_enabled = true; - - if (strcmp(buf, "off") == 0) - _debug_pagealloc_enabled = false; - - return 0; + return kstrtobool(buf, &_debug_pagealloc_enabled); } early_param("debug_pagealloc", early_debug_pagealloc); @@ -1000,7 +987,6 @@ static __always_inline bool free_pages_prepare(struct page *page, trace_mm_page_free(page, order); kmemcheck_free_shadow(page, order); - kasan_free_pages(page, order); /* * Check tail pages before head page information is cleared to @@ -1042,6 +1028,7 @@ static __always_inline bool free_pages_prepare(struct page *page, arch_free_page(page, order); kernel_poison_pages(page, 1 << order, 0); kernel_map_pages(page, 1 << order, 0); + kasan_free_pages(page, order); return true; } @@ -1212,7 +1199,7 @@ static inline void init_reserved_page(unsigned long pfn) * marks the pages PageReserved. The remaining valid pages are later * sent to the buddy page allocator. */ -void __meminit reserve_bootmem_region(unsigned long start, unsigned long end) +void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) { unsigned long start_pfn = PFN_DOWN(start); unsigned long end_pfn = PFN_UP(end); @@ -1661,6 +1648,9 @@ static void check_new_page_bad(struct page *page) if (unlikely(page->flags & __PG_HWPOISON)) { bad_reason = "HWPoisoned (hardware-corrupted)"; bad_flags = __PG_HWPOISON; + /* Don't complain about hwpoisoned pages */ + page_mapcount_reset(page); /* remove PageBuddy */ + return; } if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; @@ -2750,10 +2740,9 @@ static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) * one free page of a suitable size. Checking now avoids taking the zone lock * to check in the allocation paths if no pages are free. */ -static bool __zone_watermark_ok(struct zone *z, unsigned int order, - unsigned long mark, int classzone_idx, - unsigned int alloc_flags, - long free_pages) +bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, + int classzone_idx, unsigned int alloc_flags, + long free_pages) { long min = mark; int o; @@ -3180,34 +3169,33 @@ out: return page; } + +/* + * Maximum number of compaction retries wit a progress before OOM + * killer is consider as the only way to move forward. + */ +#define MAX_COMPACT_RETRIES 16 + #ifdef CONFIG_COMPACTION /* Try memory compaction for high-order allocations before reclaim */ static struct page * __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, unsigned int alloc_flags, const struct alloc_context *ac, - enum migrate_mode mode, int *contended_compaction, - bool *deferred_compaction) + enum migrate_mode mode, enum compact_result *compact_result) { - unsigned long compact_result; struct page *page; + int contended_compaction; if (!order) return NULL; current->flags |= PF_MEMALLOC; - compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, - mode, contended_compaction); + *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac, + mode, &contended_compaction); current->flags &= ~PF_MEMALLOC; - switch (compact_result) { - case COMPACT_DEFERRED: - *deferred_compaction = true; - /* fall-through */ - case COMPACT_SKIPPED: + if (*compact_result <= COMPACT_INACTIVE) return NULL; - default: - break; - } /* * At least in one zone compaction wasn't deferred or skipped, so let's @@ -3233,19 +3221,112 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, */ count_vm_event(COMPACTFAIL); + /* + * In all zones where compaction was attempted (and not + * deferred or skipped), lock contention has been detected. + * For THP allocation we do not want to disrupt the others + * so we fallback to base pages instead. + */ + if (contended_compaction == COMPACT_CONTENDED_LOCK) + *compact_result = COMPACT_CONTENDED; + + /* + * If compaction was aborted due to need_resched(), we do not + * want to further increase allocation latency, unless it is + * khugepaged trying to collapse. + */ + if (contended_compaction == COMPACT_CONTENDED_SCHED + && !(current->flags & PF_KTHREAD)) + *compact_result = COMPACT_CONTENDED; + cond_resched(); return NULL; } + +static inline bool +should_compact_retry(struct alloc_context *ac, int order, int alloc_flags, + enum compact_result compact_result, enum migrate_mode *migrate_mode, + int compaction_retries) +{ + int max_retries = MAX_COMPACT_RETRIES; + + if (!order) + return false; + + /* + * compaction considers all the zone as desperately out of memory + * so it doesn't really make much sense to retry except when the + * failure could be caused by weak migration mode. + */ + if (compaction_failed(compact_result)) { + if (*migrate_mode == MIGRATE_ASYNC) { + *migrate_mode = MIGRATE_SYNC_LIGHT; + return true; + } + return false; + } + + /* + * make sure the compaction wasn't deferred or didn't bail out early + * due to locks contention before we declare that we should give up. + * But do not retry if the given zonelist is not suitable for + * compaction. + */ + if (compaction_withdrawn(compact_result)) + return compaction_zonelist_suitable(ac, order, alloc_flags); + + /* + * !costly requests are much more important than __GFP_REPEAT + * 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 + * would need much more detailed feedback from compaction to + * make a better decision. + */ + if (order > PAGE_ALLOC_COSTLY_ORDER) + max_retries /= 4; + if (compaction_retries <= max_retries) + return true; + + return false; +} #else static inline struct page * __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order, unsigned int alloc_flags, const struct alloc_context *ac, - enum migrate_mode mode, int *contended_compaction, - bool *deferred_compaction) + enum migrate_mode mode, enum compact_result *compact_result) { + *compact_result = COMPACT_SKIPPED; return NULL; } + +static inline bool +should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags, + enum compact_result compact_result, + enum migrate_mode *migrate_mode, + int compaction_retries) +{ + struct zone *zone; + struct zoneref *z; + + if (!order || order > PAGE_ALLOC_COSTLY_ORDER) + return false; + + /* + * There are setups with compaction disabled which would prefer to loop + * inside the allocator rather than hit the oom killer prematurely. + * Let's give them a good hope and keep retrying while the order-0 + * watermarks are OK. + */ + for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, + ac->nodemask) { + if (zone_watermark_ok(zone, 0, min_wmark_pages(zone), + ac_classzone_idx(ac), alloc_flags)) + return true; + } + return false; +} #endif /* CONFIG_COMPACTION */ /* Perform direct synchronous page reclaim */ @@ -3377,6 +3458,101 @@ static inline bool is_thp_gfp_mask(gfp_t gfp_mask) return (gfp_mask & (GFP_TRANSHUGE | __GFP_KSWAPD_RECLAIM)) == GFP_TRANSHUGE; } +/* + * Maximum number of reclaim retries without any progress before OOM killer + * is consider as the only way to move forward. + */ +#define MAX_RECLAIM_RETRIES 16 + +/* + * Checks whether it makes sense to retry the reclaim to make a forward progress + * for the given allocation request. + * The reclaim feedback represented by did_some_progress (any progress during + * the last reclaim round) and no_progress_loops (number of reclaim rounds without + * any progress in a row) is considered as well as the reclaimable pages on the + * applicable zone list (with a backoff mechanism which is a function of + * no_progress_loops). + * + * Returns true if a retry is viable or false to enter the oom path. + */ +static inline bool +should_reclaim_retry(gfp_t gfp_mask, unsigned order, + struct alloc_context *ac, int alloc_flags, + bool did_some_progress, int no_progress_loops) +{ + struct zone *zone; + struct zoneref *z; + + /* + * Make sure we converge to OOM if we cannot make any progress + * several times in the row. + */ + if (no_progress_loops > MAX_RECLAIM_RETRIES) + return false; + + /* + * Keep reclaiming pages while there is a chance this will lead somewhere. + * If none of the target zones can satisfy our allocation request even + * if all reclaimable pages are considered then we are screwed and have + * to go OOM. + */ + for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx, + ac->nodemask) { + unsigned long available; + unsigned long reclaimable; + + available = reclaimable = zone_reclaimable_pages(zone); + available -= DIV_ROUND_UP(no_progress_loops * available, + MAX_RECLAIM_RETRIES); + available += zone_page_state_snapshot(zone, NR_FREE_PAGES); + + /* + * Would the allocation succeed if we reclaimed the whole + * available? + */ + if (__zone_watermark_ok(zone, order, min_wmark_pages(zone), + ac_classzone_idx(ac), alloc_flags, available)) { + /* + * If we didn't make any progress and have a lot of + * dirty + writeback pages then we should wait for + * an IO to complete to slow down the reclaim and + * prevent from pre mature OOM + */ + if (!did_some_progress) { + unsigned long writeback; + unsigned long dirty; + + writeback = zone_page_state_snapshot(zone, + NR_WRITEBACK); + dirty = zone_page_state_snapshot(zone, NR_FILE_DIRTY); + + if (2*(writeback + dirty) > reclaimable) { + congestion_wait(BLK_RW_ASYNC, HZ/10); + return true; + } + } + + /* + * Memory allocation/reclaim might be called from a WQ + * context and the current implementation of the WQ + * concurrency control doesn't recognize that + * a particular WQ is congested if the worker thread is + * looping without ever sleeping. Therefore we have to + * do a short sleep here rather than calling + * cond_resched(). + */ + if (current->flags & PF_WQ_WORKER) + schedule_timeout_uninterruptible(1); + else + cond_resched(); + + return true; + } + } + + return false; +} + static inline struct page * __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, struct alloc_context *ac) @@ -3384,11 +3560,11 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, bool can_direct_reclaim = gfp_mask & __GFP_DIRECT_RECLAIM; struct page *page = NULL; unsigned int alloc_flags; - unsigned long pages_reclaimed = 0; unsigned long did_some_progress; enum migrate_mode migration_mode = MIGRATE_ASYNC; - bool deferred_compaction = false; - int contended_compaction = COMPACT_CONTENDED_NONE; + enum compact_result compact_result; + int compaction_retries = 0; + int no_progress_loops = 0; /* * In the slowpath, we sanity check order to avoid ever trying to @@ -3475,8 +3651,7 @@ retry: */ page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, migration_mode, - &contended_compaction, - &deferred_compaction); + &compact_result); if (page) goto got_pg; @@ -3489,35 +3664,19 @@ retry: * to heavily disrupt the system, so we fail the allocation * instead of entering direct reclaim. */ - if (deferred_compaction) - goto nopage; - - /* - * In all zones where compaction was attempted (and not - * deferred or skipped), lock contention has been detected. - * For THP allocation we do not want to disrupt the others - * so we fallback to base pages instead. - */ - if (contended_compaction == COMPACT_CONTENDED_LOCK) + if (compact_result == COMPACT_DEFERRED) goto nopage; /* - * If compaction was aborted due to need_resched(), we do not - * want to further increase allocation latency, unless it is - * khugepaged trying to collapse. + * Compaction is contended so rather back off than cause + * excessive stalls. */ - if (contended_compaction == COMPACT_CONTENDED_SCHED - && !(current->flags & PF_KTHREAD)) + if(compact_result == COMPACT_CONTENDED) goto nopage; } - /* - * It can become very expensive to allocate transparent hugepages at - * fault, so use asynchronous memory compaction for THP unless it is - * khugepaged trying to collapse. - */ - if (!is_thp_gfp_mask(gfp_mask) || (current->flags & PF_KTHREAD)) - migration_mode = MIGRATE_SYNC_LIGHT; + if (order && compaction_made_progress(compact_result)) + compaction_retries++; /* Try direct reclaim and then allocating */ page = __alloc_pages_direct_reclaim(gfp_mask, order, alloc_flags, ac, @@ -3529,14 +3688,38 @@ retry: if (gfp_mask & __GFP_NORETRY) goto noretry; - /* Keep reclaiming pages as long as there is reasonable progress */ - pages_reclaimed += did_some_progress; - if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) || - ((gfp_mask & __GFP_REPEAT) && pages_reclaimed < (1 << order))) { - /* Wait for some write requests to complete then retry */ - wait_iff_congested(ac->preferred_zoneref->zone, BLK_RW_ASYNC, HZ/50); + /* + * Do not retry costly high order allocations unless they are + * __GFP_REPEAT + */ + if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT)) + goto noretry; + + /* + * Costly allocations might have made a progress but this doesn't mean + * their order will become available due to high fragmentation so + * always increment the no progress counter for them + */ + if (did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) + no_progress_loops = 0; + else + no_progress_loops++; + + if (should_reclaim_retry(gfp_mask, order, ac, alloc_flags, + did_some_progress > 0, no_progress_loops)) + goto retry; + + /* + * It doesn't make any sense to retry for the compaction if the order-0 + * reclaim is not able to make any progress because the current + * implementation of the compaction depends on the sufficient amount + * of free memory (see __compaction_suitable) + */ + if (did_some_progress > 0 && + should_compact_retry(ac, order, alloc_flags, + compact_result, &migration_mode, + compaction_retries)) goto retry; - } /* Reclaim has failed us, start killing things */ page = __alloc_pages_may_oom(gfp_mask, order, ac, &did_some_progress); @@ -3544,19 +3727,28 @@ retry: goto got_pg; /* Retry as long as the OOM killer is making progress */ - if (did_some_progress) + if (did_some_progress) { + no_progress_loops = 0; goto retry; + } noretry: /* - * High-order allocations do not necessarily loop after - * direct reclaim and reclaim/compaction depends on compaction - * being called after reclaim so call directly if necessary + * High-order allocations do not necessarily loop after direct reclaim + * and reclaim/compaction depends on compaction being called after + * reclaim so call directly if necessary. + * It can become very expensive to allocate transparent hugepages at + * fault, so use asynchronous memory compaction for THP unless it is + * khugepaged trying to collapse. All other requests should tolerate + * at least light sync migration. */ + if (is_thp_gfp_mask(gfp_mask) && !(current->flags & PF_KTHREAD)) + migration_mode = MIGRATE_ASYNC; + else + migration_mode = MIGRATE_SYNC_LIGHT; page = __alloc_pages_direct_compact(gfp_mask, order, alloc_flags, ac, migration_mode, - &contended_compaction, - &deferred_compaction); + &compact_result); if (page) goto got_pg; nopage: @@ -6670,49 +6862,6 @@ void setup_per_zone_wmarks(void) mutex_unlock(&zonelists_mutex); } -/* - * The inactive anon list should be small enough that the VM never has to - * do too much work, but large enough that each inactive page has a chance - * to be referenced again before it is swapped out. - * - * The inactive_anon ratio is the target ratio of ACTIVE_ANON to - * INACTIVE_ANON pages on this zone's LRU, maintained by the - * pageout code. A zone->inactive_ratio of 3 means 3:1 or 25% of - * the anonymous pages are kept on the inactive list. - * - * total target max - * memory ratio inactive anon - * ------------------------------------- - * 10MB 1 5MB - * 100MB 1 50MB - * 1GB 3 250MB - * 10GB 10 0.9GB - * 100GB 31 3GB - * 1TB 101 10GB - * 10TB 320 32GB - */ -static void __meminit calculate_zone_inactive_ratio(struct zone *zone) -{ - unsigned int gb, ratio; - - /* Zone size in gigabytes */ - gb = zone->managed_pages >> (30 - PAGE_SHIFT); - if (gb) - ratio = int_sqrt(10 * gb); - else - ratio = 1; - - zone->inactive_ratio = ratio; -} - -static void __meminit setup_per_zone_inactive_ratio(void) -{ - struct zone *zone; - - for_each_zone(zone) - calculate_zone_inactive_ratio(zone); -} - /* * Initialise min_free_kbytes. * @@ -6758,7 +6907,6 @@ int __meminit init_per_zone_wmark_min(void) setup_per_zone_wmarks(); refresh_zone_stat_thresholds(); setup_per_zone_lowmem_reserve(); - setup_per_zone_inactive_ratio(); return 0; } core_initcall(init_per_zone_wmark_min)