diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/page_ext.h | 10 | ||||
| -rw-r--r-- | include/linux/page_owner.h | 38 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 16 | ||||
| -rw-r--r-- | mm/Makefile | 1 | ||||
| -rw-r--r-- | mm/page_alloc.c | 11 | ||||
| -rw-r--r-- | mm/page_ext.c | 4 | ||||
| -rw-r--r-- | mm/page_owner.c | 222 | ||||
| -rw-r--r-- | mm/vmstat.c | 101 | ||||
| -rw-r--r-- | tools/vm/Makefile | 4 | ||||
| -rw-r--r-- | tools/vm/page_owner_sort.c | 144 |
11 files changed, 554 insertions, 3 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 6f067954675b..68153642c44e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2513,6 +2513,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. OSS [HW,OSS] See Documentation/sound/oss/oss-parameters.txt + page_owner= [KNL] Boot-time page_owner enabling option. + Storage of the information about who allocated + each page is disabled in default. With this switch, + we can turn it on. + on: enable the feature + panic= [KNL] Kernel behaviour on panic: delay <timeout> timeout > 0: seconds before rebooting timeout = 0: wait forever diff --git a/include/linux/page_ext.h b/include/linux/page_ext.h index 61c0f05f9069..d2a2c84c72d0 100644 --- a/include/linux/page_ext.h +++ b/include/linux/page_ext.h @@ -1,6 +1,9 @@ #ifndef __LINUX_PAGE_EXT_H #define __LINUX_PAGE_EXT_H +#include <linux/types.h> +#include <linux/stacktrace.h> + struct pglist_data; struct page_ext_operations { bool (*need)(void); @@ -22,6 +25,7 @@ struct page_ext_operations { enum page_ext_flags { PAGE_EXT_DEBUG_POISON, /* Page is poisoned */ PAGE_EXT_DEBUG_GUARD, + PAGE_EXT_OWNER, }; /* @@ -33,6 +37,12 @@ enum page_ext_flags { */ struct page_ext { unsigned long flags; +#ifdef CONFIG_PAGE_OWNER + unsigned int order; + gfp_t gfp_mask; + struct stack_trace trace; + unsigned long trace_entries[8]; +#endif }; extern void pgdat_page_ext_init(struct pglist_data *pgdat); diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h new file mode 100644 index 000000000000..b48c3471c254 --- /dev/null +++ b/include/linux/page_owner.h @@ -0,0 +1,38 @@ +#ifndef __LINUX_PAGE_OWNER_H +#define __LINUX_PAGE_OWNER_H + +#ifdef CONFIG_PAGE_OWNER +extern bool page_owner_inited; +extern struct page_ext_operations page_owner_ops; + +extern void __reset_page_owner(struct page *page, unsigned int order); +extern void __set_page_owner(struct page *page, + unsigned int order, gfp_t gfp_mask); + +static inline void reset_page_owner(struct page *page, unsigned int order) +{ + if (likely(!page_owner_inited)) + return; + + __reset_page_owner(page, order); +} + +static inline void set_page_owner(struct page *page, + unsigned int order, gfp_t gfp_mask) +{ + if (likely(!page_owner_inited)) + return; + + __set_page_owner(page, order, gfp_mask); +} +#else +static inline void reset_page_owner(struct page *page, unsigned int order) +{ +} +static inline void set_page_owner(struct page *page, + unsigned int order, gfp_t gfp_mask) +{ +} + +#endif /* CONFIG_PAGE_OWNER */ +#endif /* __LINUX_PAGE_OWNER_H */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d780351835e9..5f2ce616c046 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -227,6 +227,22 @@ config UNUSED_SYMBOLS you really need it, and what the merge plan to the mainline kernel for your module is. +config PAGE_OWNER + bool "Track page owner" + depends on DEBUG_KERNEL && STACKTRACE_SUPPORT + select DEBUG_FS + select STACKTRACE + select PAGE_EXTENSION + help + This keeps track of what call chain is the owner of a page, may + help to find bare alloc_page(s) leaks. Even if you include this + feature on your build, it is disabled in default. You should pass + "page_owner=on" to boot parameter in order to enable it. Eats + a fair amount of memory if enabled. See tools/vm/page_owner_sort.c + for user-space helper. + + If unsure, say N. + config DEBUG_FS bool "Debug Filesystem" help diff --git a/mm/Makefile b/mm/Makefile index 580cd3f392af..4bf586e66378 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -63,6 +63,7 @@ obj-$(CONFIG_MEMORY_FAILURE) += memory-failure.o obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o +obj-$(CONFIG_PAGE_OWNER) += page_owner.o obj-$(CONFIG_CLEANCACHE) += cleancache.o obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o obj-$(CONFIG_ZPOOL) += zpool.o diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 303d38516807..c13b6b29add2 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -59,6 +59,7 @@ #include <linux/page_ext.h> #include <linux/hugetlb.h> #include <linux/sched/rt.h> +#include <linux/page_owner.h> #include <asm/sections.h> #include <asm/tlbflush.h> @@ -813,6 +814,8 @@ static bool free_pages_prepare(struct page *page, unsigned int order) if (bad) return false; + reset_page_owner(page, order); + if (!PageHighMem(page)) { debug_check_no_locks_freed(page_address(page), PAGE_SIZE << order); @@ -988,6 +991,8 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags) if (order && (gfp_flags & __GFP_COMP)) prep_compound_page(page, order); + set_page_owner(page, order, gfp_flags); + return 0; } @@ -1560,8 +1565,11 @@ void split_page(struct page *page, unsigned int order) split_page(virt_to_page(page[0].shadow), order); #endif - for (i = 1; i < (1 << order); i++) + set_page_owner(page, 0, 0); + for (i = 1; i < (1 << order); i++) { set_page_refcounted(page + i); + set_page_owner(page + i, 0, 0); + } } EXPORT_SYMBOL_GPL(split_page); @@ -1601,6 +1609,7 @@ int __isolate_free_page(struct page *page, unsigned int order) } } + set_page_owner(page, order, 0); return 1UL << order; } diff --git a/mm/page_ext.c b/mm/page_ext.c index c2cd7b15f0de..d86fd2f5353f 100644 --- a/mm/page_ext.c +++ b/mm/page_ext.c @@ -5,6 +5,7 @@ #include <linux/memory.h> #include <linux/vmalloc.h> #include <linux/kmemleak.h> +#include <linux/page_owner.h> /* * struct page extension @@ -55,6 +56,9 @@ static struct page_ext_operations *page_ext_ops[] = { #ifdef CONFIG_PAGE_POISONING &page_poisoning_ops, #endif +#ifdef CONFIG_PAGE_OWNER + &page_owner_ops, +#endif }; static unsigned long total_usage; diff --git a/mm/page_owner.c b/mm/page_owner.c new file mode 100644 index 000000000000..85eec7ea6735 --- /dev/null +++ b/mm/page_owner.c @@ -0,0 +1,222 @@ +#include <linux/debugfs.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/bootmem.h> +#include <linux/stacktrace.h> +#include <linux/page_owner.h> +#include "internal.h" + +static bool page_owner_disabled = true; +bool page_owner_inited __read_mostly; + +static int early_page_owner_param(char *buf) +{ + if (!buf) + return -EINVAL; + + if (strcmp(buf, "on") == 0) + page_owner_disabled = false; + + return 0; +} +early_param("page_owner", early_page_owner_param); + +static bool need_page_owner(void) +{ + if (page_owner_disabled) + return false; + + return true; +} + +static void init_page_owner(void) +{ + if (page_owner_disabled) + return; + + page_owner_inited = true; +} + +struct page_ext_operations page_owner_ops = { + .need = need_page_owner, + .init = init_page_owner, +}; + +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); + __clear_bit(PAGE_EXT_OWNER, &page_ext->flags); + } +} + +void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask) +{ + struct page_ext *page_ext; + struct stack_trace *trace; + + page_ext = lookup_page_ext(page); + + trace = &page_ext->trace; + trace->nr_entries = 0; + trace->max_entries = ARRAY_SIZE(page_ext->trace_entries); + trace->entries = &page_ext->trace_entries[0]; + trace->skip = 3; + save_stack_trace(&page_ext->trace); + + page_ext->order = order; + page_ext->gfp_mask = gfp_mask; + + __set_bit(PAGE_EXT_OWNER, &page_ext->flags); +} + +static ssize_t +print_page_owner(char __user *buf, size_t count, unsigned long pfn, + struct page *page, struct page_ext *page_ext) +{ + int ret; + int pageblock_mt, page_mt; + char *kbuf; + + kbuf = kmalloc(count, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + ret = snprintf(kbuf, count, + "Page allocated via order %u, mask 0x%x\n", + page_ext->order, page_ext->gfp_mask); + + if (ret >= count) + goto err; + + /* Print information relevant to grouping pages by mobility */ + pageblock_mt = get_pfnblock_migratetype(page, pfn); + page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); + ret += snprintf(kbuf + ret, count - ret, + "PFN %lu Block %lu type %d %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", + pfn, + pfn >> pageblock_order, + pageblock_mt, + pageblock_mt != page_mt ? "Fallback" : " ", + PageLocked(page) ? "K" : " ", + PageError(page) ? "E" : " ", + PageReferenced(page) ? "R" : " ", + PageUptodate(page) ? "U" : " ", + PageDirty(page) ? "D" : " ", + PageLRU(page) ? "L" : " ", + PageActive(page) ? "A" : " ", + PageSlab(page) ? "S" : " ", + PageWriteback(page) ? "W" : " ", + PageCompound(page) ? "C" : " ", + PageSwapCache(page) ? "B" : " ", + PageMappedToDisk(page) ? "M" : " "); + + if (ret >= count) + goto err; + + ret += snprint_stack_trace(kbuf + ret, count - ret, + &page_ext->trace, 0); + if (ret >= count) + goto err; + + ret += snprintf(kbuf + ret, count - ret, "\n"); + if (ret >= count) + goto err; + + if (copy_to_user(buf, kbuf, ret)) + ret = -EFAULT; + + kfree(kbuf); + return ret; + +err: + kfree(kbuf); + return -ENOMEM; +} + +static ssize_t +read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) +{ + unsigned long pfn; + struct page *page; + struct page_ext *page_ext; + + if (!page_owner_inited) + return -EINVAL; + + page = NULL; + pfn = min_low_pfn + *ppos; + + /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */ + while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) + pfn++; + + drain_all_pages(NULL); + + /* Find an allocated page */ + for (; pfn < max_pfn; pfn++) { + /* + * If the new page is in a new MAX_ORDER_NR_PAGES area, + * validate the area as existing, skip it if not + */ + if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) { + pfn += MAX_ORDER_NR_PAGES - 1; + continue; + } + + /* Check for holes within a MAX_ORDER area */ + if (!pfn_valid_within(pfn)) + continue; + + page = pfn_to_page(pfn); + if (PageBuddy(page)) { + unsigned long freepage_order = page_order_unsafe(page); + + if (freepage_order < MAX_ORDER) + pfn += (1UL << freepage_order) - 1; + continue; + } + + page_ext = lookup_page_ext(page); + + /* + * Pages allocated before initialization of page_owner are + * non-buddy and have no page_owner info. + */ + if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) + continue; + + /* Record the next PFN to read in the file offset */ + *ppos = (pfn - min_low_pfn) + 1; + + return print_page_owner(buf, count, pfn, page, page_ext); + } + + return 0; +} + +static const struct file_operations proc_page_owner_operations = { + .read = read_page_owner, +}; + +static int __init pageowner_init(void) +{ + struct dentry *dentry; + + if (!page_owner_inited) { + pr_info("page_owner is disabled\n"); + return 0; + } + + dentry = debugfs_create_file("page_owner", S_IRUSR, NULL, + NULL, &proc_page_owner_operations); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + return 0; +} +module_init(pageowner_init) diff --git a/mm/vmstat.c b/mm/vmstat.c index 1b12d390dc68..b090e9e3d626 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -22,6 +22,8 @@ #include <linux/writeback.h> #include <linux/compaction.h> #include <linux/mm_inline.h> +#include <linux/page_ext.h> +#include <linux/page_owner.h> #include "internal.h" @@ -1017,6 +1019,104 @@ static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg) return 0; } +#ifdef CONFIG_PAGE_OWNER +static void pagetypeinfo_showmixedcount_print(struct seq_file *m, + pg_data_t *pgdat, + struct zone *zone) +{ + struct page *page; + struct page_ext *page_ext; + unsigned long pfn = zone->zone_start_pfn, block_end_pfn; + unsigned long end_pfn = pfn + zone->spanned_pages; + unsigned long count[MIGRATE_TYPES] = { 0, }; + int pageblock_mt, page_mt; + int i; + + /* Scan block by block. First and last block may be incomplete */ + pfn = zone->zone_start_pfn; + + /* + * Walk the zone in pageblock_nr_pages steps. If a page block spans + * a zone boundary, it will be double counted between zones. This does + * not matter as the mixed block count will still be correct + */ + for (; pfn < end_pfn; ) { + if (!pfn_valid(pfn)) { + pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); + continue; + } + + 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_pfnblock_migratetype(page, pfn); + + for (; pfn < block_end_pfn; pfn++) { + if (!pfn_valid_within(pfn)) + continue; + + page = pfn_to_page(pfn); + if (PageBuddy(page)) { + pfn += (1UL << page_order(page)) - 1; + continue; + } + + if (PageReserved(page)) + continue; + + page_ext = lookup_page_ext(page); + + if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) + continue; + + page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); + if (pageblock_mt != page_mt) { + if (is_migrate_cma(pageblock_mt)) + count[MIGRATE_MOVABLE]++; + else + count[pageblock_mt]++; + + pfn = block_end_pfn; + break; + } + pfn += (1UL << page_ext->order) - 1; + } + } + + /* Print counts */ + seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); + for (i = 0; i < MIGRATE_TYPES; i++) + seq_printf(m, "%12lu ", count[i]); + seq_putc(m, '\n'); +} +#endif /* CONFIG_PAGE_OWNER */ + +/* + * Print out the number of pageblocks for each migratetype that contain pages + * of other types. This gives an indication of how well fallbacks are being + * contained by rmqueue_fallback(). It requires information from PAGE_OWNER + * to determine what is going on + */ +static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) +{ +#ifdef CONFIG_PAGE_OWNER + int mtype; + + if (!page_owner_inited) + return; + + drain_all_pages(NULL); + + seq_printf(m, "\n%-23s", "Number of mixed blocks "); + for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) + seq_printf(m, "%12s ", migratetype_names[mtype]); + seq_putc(m, '\n'); + + walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print); +#endif /* CONFIG_PAGE_OWNER */ +} + /* * This prints out statistics in relation to grouping pages by mobility. * It is expensive to collect so do not constantly read the file. @@ -1034,6 +1134,7 @@ static int pagetypeinfo_show(struct seq_file *m, void *arg) seq_putc(m, '\n'); pagetypeinfo_showfree(m, pgdat); pagetypeinfo_showblockcount(m, pgdat); + pagetypeinfo_showmixedcount(m, pgdat); return 0; } diff --git a/tools/vm/Makefile b/tools/vm/Makefile index 3d907dacf2ac..ac884b65a072 100644 --- a/tools/vm/Makefile +++ b/tools/vm/Makefile @@ -1,6 +1,6 @@ # Makefile for vm tools # -TARGETS=page-types slabinfo +TARGETS=page-types slabinfo page_owner_sort LIB_DIR = ../lib/api LIBS = $(LIB_DIR)/libapikfs.a @@ -18,5 +18,5 @@ $(LIBS): $(CC) $(CFLAGS) -o $@ $< $(LDFLAGS) clean: - $(RM) page-types slabinfo + $(RM) page-types slabinfo page_owner_sort make -C $(LIB_DIR) clean diff --git a/tools/vm/page_owner_sort.c b/tools/vm/page_owner_sort.c new file mode 100644 index 000000000000..77147b42d598 --- /dev/null +++ b/tools/vm/page_owner_sort.c @@ -0,0 +1,144 @@ +/* + * User-space helper to sort the output of /sys/kernel/debug/page_owner + * + * Example use: + * cat /sys/kernel/debug/page_owner > page_owner_full.txt + * grep -v ^PFN page_owner_full.txt > page_owner.txt + * ./sort page_owner.txt sorted_page_owner.txt +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> + +struct block_list { + char *txt; + int len; + int num; +}; + + +static struct block_list *list; +static int list_size; +static int max_size; + +struct block_list *block_head; + +int read_block(char *buf, int buf_size, FILE *fin) +{ + char *curr = buf, *const buf_end = buf + buf_size; + + while (buf_end - curr > 1 && fgets(curr, buf_end - curr, fin)) { + if (*curr == '\n') /* empty line */ + return curr - buf; + curr += strlen(curr); + } + + return -1; /* EOF or no space left in buf. */ +} + +static int compare_txt(const void *p1, const void *p2) +{ + const struct block_list *l1 = p1, *l2 = p2; + + return strcmp(l1->txt, l2->txt); +} + +static int compare_num(const void *p1, const void *p2) +{ + const struct block_list *l1 = p1, *l2 = p2; + + return l2->num - l1->num; +} + +static void add_list(char *buf, int len) +{ + if (list_size != 0 && + len == list[list_size-1].len && + memcmp(buf, list[list_size-1].txt, len) == 0) { + list[list_size-1].num++; + return; + } + if (list_size == max_size) { + printf("max_size too small??\n"); + exit(1); + } + list[list_size].txt = malloc(len+1); + list[list_size].len = len; + list[list_size].num = 1; + memcpy(list[list_size].txt, buf, len); + list[list_size].txt[len] = 0; + list_size++; + if (list_size % 1000 == 0) { + printf("loaded %d\r", list_size); + fflush(stdout); + } +} + +#define BUF_SIZE 1024 + +int main(int argc, char **argv) +{ + FILE *fin, *fout; + char buf[BUF_SIZE]; + int ret, i, count; + struct block_list *list2; + struct stat st; + + if (argc < 3) { + printf("Usage: ./program <input> <output>\n"); + perror("open: "); + exit(1); + } + + fin = fopen(argv[1], "r"); + fout = fopen(argv[2], "w"); + if (!fin || !fout) { + printf("Usage: ./program <input> <output>\n"); + perror("open: "); + exit(1); + } + + fstat(fileno(fin), &st); + max_size = st.st_size / 100; /* hack ... */ + + list = malloc(max_size * sizeof(*list)); + + for ( ; ; ) { + ret = read_block(buf, BUF_SIZE, fin); + if (ret < 0) + break; + + add_list(buf, ret); + } + + printf("loaded %d\n", list_size); + + printf("sorting ....\n"); + + qsort(list, list_size, sizeof(list[0]), compare_txt); + + list2 = malloc(sizeof(*list) * list_size); + + printf("culling\n"); + + for (i = count = 0; i < list_size; i++) { + if (count == 0 || + strcmp(list2[count-1].txt, list[i].txt) != 0) { + list2[count++] = list[i]; + } else { + list2[count-1].num += list[i].num; + } + } + + qsort(list2, count, sizeof(list[0]), compare_num); + + for (i = 0; i < count; i++) + fprintf(fout, "%d times:\n%s\n", list2[i].num, list2[i].txt); + + return 0; +} |