diff options
Diffstat (limited to 'mm/page_owner.c')
| -rw-r--r-- | mm/page_owner.c | 131 |
1 files changed, 87 insertions, 44 deletions
diff --git a/mm/page_owner.c b/mm/page_owner.c index addcbb2ae4e4..18ecde9f45b2 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -24,9 +24,10 @@ struct page_owner { short last_migrate_reason; gfp_t gfp_mask; depot_stack_handle_t handle; + depot_stack_handle_t free_handle; }; -static bool page_owner_disabled = true; +static bool page_owner_enabled = false; DEFINE_STATIC_KEY_FALSE(page_owner_inited); static depot_stack_handle_t dummy_handle; @@ -41,7 +42,7 @@ static int __init early_page_owner_param(char *buf) return -EINVAL; if (strcmp(buf, "on") == 0) - page_owner_disabled = false; + page_owner_enabled = true; return 0; } @@ -49,10 +50,7 @@ early_param("page_owner", early_page_owner_param); static bool need_page_owner(void) { - if (page_owner_disabled) - return false; - - return true; + return page_owner_enabled; } static __always_inline depot_stack_handle_t create_dummy_stack(void) @@ -81,7 +79,7 @@ static noinline void register_early_stack(void) static void init_page_owner(void) { - if (page_owner_disabled) + if (!page_owner_enabled) return; register_dummy_stack(); @@ -102,19 +100,6 @@ static inline struct page_owner *get_page_owner(struct page_ext *page_ext) return (void *)page_ext + page_owner_ops.offset; } -void __reset_page_owner(struct page *page, unsigned int order) -{ - int i; - struct page_ext *page_ext; - - for (i = 0; i < (1 << order); i++) { - page_ext = lookup_page_ext(page + i); - if (unlikely(!page_ext)) - continue; - __clear_bit(PAGE_EXT_OWNER, &page_ext->flags); - } -} - static inline bool check_recursive_alloc(unsigned long *entries, unsigned int nr_entries, unsigned long ip) @@ -154,18 +139,44 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags) return handle; } -static inline void __set_page_owner_handle(struct page_ext *page_ext, - depot_stack_handle_t handle, unsigned int order, gfp_t gfp_mask) +void __reset_page_owner(struct page *page, unsigned int order) { + int i; + struct page_ext *page_ext; + depot_stack_handle_t handle = 0; struct page_owner *page_owner; - page_owner = get_page_owner(page_ext); - page_owner->handle = handle; - page_owner->order = order; - page_owner->gfp_mask = gfp_mask; - page_owner->last_migrate_reason = -1; + handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); + + page_ext = lookup_page_ext(page); + if (unlikely(!page_ext)) + return; + for (i = 0; i < (1 << order); i++) { + __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); + page_owner = get_page_owner(page_ext); + page_owner->free_handle = handle; + page_ext = page_ext_next(page_ext); + } +} + +static inline void __set_page_owner_handle(struct page *page, + struct page_ext *page_ext, depot_stack_handle_t handle, + unsigned int order, gfp_t gfp_mask) +{ + struct page_owner *page_owner; + int i; - __set_bit(PAGE_EXT_OWNER, &page_ext->flags); + for (i = 0; i < (1 << order); i++) { + page_owner = get_page_owner(page_ext); + page_owner->handle = handle; + page_owner->order = order; + page_owner->gfp_mask = gfp_mask; + page_owner->last_migrate_reason = -1; + __set_bit(PAGE_EXT_OWNER, &page_ext->flags); + __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); + + page_ext = page_ext_next(page_ext); + } } noinline void __set_page_owner(struct page *page, unsigned int order, @@ -178,7 +189,7 @@ noinline void __set_page_owner(struct page *page, unsigned int order, return; handle = save_stack(gfp_mask); - __set_page_owner_handle(page_ext, handle, order, gfp_mask); + __set_page_owner_handle(page, page_ext, handle, order, gfp_mask); } void __set_page_owner_migrate_reason(struct page *page, int reason) @@ -202,10 +213,11 @@ void __split_page_owner(struct page *page, unsigned int order) if (unlikely(!page_ext)) return; - page_owner = get_page_owner(page_ext); - page_owner->order = 0; - for (i = 1; i < (1 << order); i++) - __copy_page_owner(page, page + i); + for (i = 0; i < (1 << order); i++) { + page_owner = get_page_owner(page_ext); + page_owner->order = 0; + page_ext = page_ext_next(page_ext); + } } void __copy_page_owner(struct page *oldpage, struct page *newpage) @@ -235,6 +247,7 @@ void __copy_page_owner(struct page *oldpage, struct page *newpage) * the new page, which will be freed. */ __set_bit(PAGE_EXT_OWNER, &new_ext->flags); + __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags); } void pagetypeinfo_showmixedcount_print(struct seq_file *m, @@ -258,7 +271,8 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, * not matter as the mixed block count will still be correct */ for (; pfn < end_pfn; ) { - if (!pfn_valid(pfn)) { + page = pfn_to_online_page(pfn); + if (!page) { pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); continue; } @@ -266,13 +280,13 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); block_end_pfn = min(block_end_pfn, end_pfn); - page = pfn_to_page(pfn); pageblock_mt = get_pageblock_migratetype(page); for (; pfn < block_end_pfn; pfn++) { if (!pfn_valid_within(pfn)) continue; + /* The pageblock is online, no need to recheck. */ page = pfn_to_page(pfn); if (page_zone(page) != zone) @@ -294,7 +308,7 @@ void pagetypeinfo_showmixedcount_print(struct seq_file *m, if (unlikely(!page_ext)) continue; - if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) + if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) continue; page_owner = get_page_owner(page_ext); @@ -405,20 +419,34 @@ void __dump_page_owner(struct page *page) mt = gfpflags_to_migratetype(gfp_mask); if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) { - pr_alert("page_owner info is not active (free page?)\n"); + pr_alert("page_owner info is not present (never set?)\n"); return; } + if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) + pr_alert("page_owner tracks the page as allocated\n"); + else + pr_alert("page_owner tracks the page as freed\n"); + + pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", + page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); + handle = READ_ONCE(page_owner->handle); if (!handle) { - pr_alert("page_owner info is not active (free page?)\n"); - return; + pr_alert("page_owner allocation stack trace missing\n"); + } else { + nr_entries = stack_depot_fetch(handle, &entries); + stack_trace_print(entries, nr_entries, 0); } - nr_entries = stack_depot_fetch(handle, &entries); - pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", - page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); - stack_trace_print(entries, nr_entries, 0); + handle = READ_ONCE(page_owner->free_handle); + if (!handle) { + pr_alert("page_owner free stack trace missing\n"); + } else { + nr_entries = stack_depot_fetch(handle, &entries); + pr_alert("page last free stack trace:\n"); + stack_trace_print(entries, nr_entries, 0); + } if (page_owner->last_migrate_reason != -1) pr_alert("page has been migrated, last migrate reason: %s\n", @@ -481,9 +509,23 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) continue; + /* + * Although we do have the info about past allocation of free + * pages, it's not relevant for current memory usage. + */ + if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) + continue; + page_owner = get_page_owner(page_ext); /* + * Don't print "tail" pages of high-order allocations as that + * would inflate the stats. + */ + if (!IS_ALIGNED(pfn, 1 << page_owner->order)) + continue; + + /* * Access to page_ext->handle isn't synchronous so we should * be careful to access it. */ @@ -562,7 +604,8 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) continue; /* Found early allocated page */ - __set_page_owner_handle(page_ext, early_handle, 0, 0); + __set_page_owner_handle(page, page_ext, early_handle, + 0, 0); count++; } cond_resched(); |