short last_migrate_reason;
gfp_t gfp_mask;
depot_stack_handle_t handle;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ depot_stack_handle_t free_handle;
+#endif
};
static bool page_owner_disabled = true;
static __always_inline depot_stack_handle_t create_dummy_stack(void)
{
unsigned long entries[4];
- struct stack_trace dummy;
+ unsigned int nr_entries;
- dummy.nr_entries = 0;
- dummy.max_entries = ARRAY_SIZE(entries);
- dummy.entries = &entries[0];
- dummy.skip = 0;
-
- save_stack_trace(&dummy);
- return depot_save_stack(&dummy, GFP_KERNEL);
+ nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
+ return stack_depot_save(entries, nr_entries, GFP_KERNEL);
}
static noinline void register_dummy_stack(void)
return (void *)page_ext + page_owner_ops.offset;
}
-void __reset_page_owner(struct page *page, unsigned int order)
+static inline bool check_recursive_alloc(unsigned long *entries,
+ unsigned int nr_entries,
+ unsigned long ip)
{
- 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(struct stack_trace *trace,
- unsigned long ip)
-{
- int i;
-
- if (!trace->nr_entries)
- return false;
+ unsigned int i;
- for (i = 0; i < trace->nr_entries; i++) {
- if (trace->entries[i] == ip)
+ for (i = 0; i < nr_entries; i++) {
+ if (entries[i] == ip)
return true;
}
-
return false;
}
static noinline depot_stack_handle_t save_stack(gfp_t flags)
{
unsigned long entries[PAGE_OWNER_STACK_DEPTH];
- struct stack_trace trace = {
- .nr_entries = 0,
- .entries = entries,
- .max_entries = PAGE_OWNER_STACK_DEPTH,
- .skip = 2
- };
depot_stack_handle_t handle;
+ unsigned int nr_entries;
- save_stack_trace(&trace);
- if (trace.nr_entries != 0 &&
- trace.entries[trace.nr_entries-1] == ULONG_MAX)
- trace.nr_entries--;
+ nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
/*
- * We need to check recursion here because our request to stackdepot
- * could trigger memory allocation to save new entry. New memory
- * allocation would reach here and call depot_save_stack() again
- * if we don't catch it. There is still not enough memory in stackdepot
- * so it would try to allocate memory again and loop forever.
+ * We need to check recursion here because our request to
+ * stackdepot could trigger memory allocation to save new
+ * entry. New memory allocation would reach here and call
+ * stack_depot_save_entries() again if we don't catch it. There is
+ * still not enough memory in stackdepot so it would try to
+ * allocate memory again and loop forever.
*/
- if (check_recursive_alloc(&trace, _RET_IP_))
+ if (check_recursive_alloc(entries, nr_entries, _RET_IP_))
return dummy_handle;
- handle = depot_save_stack(&trace, flags);
+ handle = stack_depot_save(entries, nr_entries, flags);
if (!handle)
handle = failure_handle;
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;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ 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;
+ if (debug_pagealloc_enabled())
+ handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
+#endif
+
+ for (i = 0; i < (1 << order); i++) {
+ page_ext = lookup_page_ext(page + i);
+ if (unlikely(!page_ext))
+ continue;
+ __clear_bit(PAGE_EXT_OWNER_ACTIVE, &page_ext->flags);
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if (debug_pagealloc_enabled()) {
+ page_owner = get_page_owner(page_ext);
+ page_owner->free_handle = handle;
+ }
+#endif
+ }
+}
- __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
+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;
+
+ 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_ACTIVE, &page_ext->flags);
+
+ page_ext = lookup_page_ext(page + i);
+ }
}
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)
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 = 1; i < (1 << order); i++) {
+ page_ext = lookup_page_ext(page + i);
+ page_owner = get_page_owner(page_ext);
+ page_owner->order = 0;
+ }
}
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_ACTIVE, &new_ext->flags);
}
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_ACTIVE, &page_ext->flags))
continue;
page_owner = get_page_owner(page_ext);
struct page *page, struct page_owner *page_owner,
depot_stack_handle_t handle)
{
- int ret;
- int pageblock_mt, page_mt;
+ int ret, pageblock_mt, page_mt;
+ unsigned long *entries;
+ unsigned int nr_entries;
char *kbuf;
- unsigned long entries[PAGE_OWNER_STACK_DEPTH];
- struct stack_trace trace = {
- .nr_entries = 0,
- .entries = entries,
- .max_entries = PAGE_OWNER_STACK_DEPTH,
- .skip = 0
- };
count = min_t(size_t, count, PAGE_SIZE);
kbuf = kmalloc(count, GFP_KERNEL);
if (ret >= count)
goto err;
- depot_fetch_stack(handle, &trace);
- ret += snprint_stack_trace(kbuf + ret, count - ret, &trace, 0);
+ nr_entries = stack_depot_fetch(handle, &entries);
+ ret += stack_trace_snprint(kbuf + ret, count - ret, entries, nr_entries, 0);
if (ret >= count)
goto err;
{
struct page_ext *page_ext = lookup_page_ext(page);
struct page_owner *page_owner;
- unsigned long entries[PAGE_OWNER_STACK_DEPTH];
- struct stack_trace trace = {
- .nr_entries = 0,
- .entries = entries,
- .max_entries = PAGE_OWNER_STACK_DEPTH,
- .skip = 0
- };
depot_stack_handle_t handle;
+ unsigned long *entries;
+ unsigned int nr_entries;
gfp_t gfp_mask;
int mt;
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_ACTIVE, &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);
}
- depot_fetch_stack(handle, &trace);
- pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n",
- page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask);
- print_stack_trace(&trace, 0);
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ 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);
+ }
+#endif
if (page_owner->last_migrate_reason != -1)
pr_alert("page has been migrated, last migrate reason: %s\n",
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_ACTIVE, &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.
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();