diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6f067954675b903e5520d89784ba6cafced90271..68153642c44eeec0efe633016135f02c70e074c8 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 61c0f05f90694701653d206009a79635f7b1f655..d2a2c84c72d04aa7a7b993be3c40df100015790e 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 0000000000000000000000000000000000000000..b48c3471c254471ed940921ab7bb4832d6f92023
--- /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 d780351835e9cb9e0b9bcf26f0e85f43d11f15c4..5f2ce616c0462db9b9055528110268385b2b653e 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 580cd3f392af80891d491838c4da7a3954a90182..4bf586e663783a9a0e5992a01aacf044f199b2c9 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 303d385168076d558cf50768d24c8ac21354b7c8..c13b6b29add2d3294b9fb2f549363c54f2e42d14 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 c2cd7b15f0defdcbe0faae0b2177e994d8097285..d86fd2f5353fcb05d39c27887f64b81e148a2bc6 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 0000000000000000000000000000000000000000..85eec7ea6735390c6430efaa75dd1221dfd0f181
--- /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 1b12d390dc6815d136cb0c812d00169c6f52895f..b090e9e3d6264c2ef80d35bf0fef230496d62a2a 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 3d907dacf2ac85c4e9d17a5dec1808859c27f5f5..ac884b65a0725fc9b4e2ed46a490996524fd96a3 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 0000000000000000000000000000000000000000..77147b42d598be985abd087e5eb8ea5ea95875fc
--- /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;
+}