Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 728 insertions, 0 deletions

diff --git a/mm/page_owner.c b/mm/page_owner.c
new file mode 100644
index 0000000000..4e2723e1b3
--- /dev/null
+++ b/mm/page_owner.c
@@ -0,0 +1,728 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/debugfs.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/memblock.h>
+#include <linux/stacktrace.h>
+#include <linux/page_owner.h>
+#include <linux/jump_label.h>
+#include <linux/migrate.h>
+#include <linux/stackdepot.h>
+#include <linux/seq_file.h>
+#include <linux/memcontrol.h>
+#include <linux/sched/clock.h>
+
+#include "internal.h"
+
+/*
+ * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack)
+ * to use off stack temporal storage
+ */
+#define PAGE_OWNER_STACK_DEPTH (16)
+
+struct page_owner {
+	unsigned short order;
+	short last_migrate_reason;
+	gfp_t gfp_mask;
+	depot_stack_handle_t handle;
+	depot_stack_handle_t free_handle;
+	u64 ts_nsec;
+	u64 free_ts_nsec;
+	char comm[TASK_COMM_LEN];
+	pid_t pid;
+	pid_t tgid;
+};
+
+static bool page_owner_enabled __initdata;
+DEFINE_STATIC_KEY_FALSE(page_owner_inited);
+
+static depot_stack_handle_t dummy_handle;
+static depot_stack_handle_t failure_handle;
+static depot_stack_handle_t early_handle;
+
+static void init_early_allocated_pages(void);
+
+static int __init early_page_owner_param(char *buf)
+{
+	int ret = kstrtobool(buf, &page_owner_enabled);
+
+	if (page_owner_enabled)
+		stack_depot_request_early_init();
+
+	return ret;
+}
+early_param("page_owner", early_page_owner_param);
+
+static __init bool need_page_owner(void)
+{
+	return page_owner_enabled;
+}
+
+static __always_inline depot_stack_handle_t create_dummy_stack(void)
+{
+	unsigned long entries[4];
+	unsigned int nr_entries;
+
+	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)
+{
+	dummy_handle = create_dummy_stack();
+}
+
+static noinline void register_failure_stack(void)
+{
+	failure_handle = create_dummy_stack();
+}
+
+static noinline void register_early_stack(void)
+{
+	early_handle = create_dummy_stack();
+}
+
+static __init void init_page_owner(void)
+{
+	if (!page_owner_enabled)
+		return;
+
+	register_dummy_stack();
+	register_failure_stack();
+	register_early_stack();
+	static_branch_enable(&page_owner_inited);
+	init_early_allocated_pages();
+}
+
+struct page_ext_operations page_owner_ops = {
+	.size = sizeof(struct page_owner),
+	.need = need_page_owner,
+	.init = init_page_owner,
+	.need_shared_flags = true,
+};
+
+static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
+{
+	return page_ext_data(page_ext, &page_owner_ops);
+}
+
+static noinline depot_stack_handle_t save_stack(gfp_t flags)
+{
+	unsigned long entries[PAGE_OWNER_STACK_DEPTH];
+	depot_stack_handle_t handle;
+	unsigned int nr_entries;
+
+	/*
+	 * Avoid recursion.
+	 *
+	 * Sometimes page metadata allocation tracking requires more
+	 * memory to be allocated:
+	 * - when new stack trace is saved to stack depot
+	 * - when backtrace itself is calculated (ia64)
+	 */
+	if (current->in_page_owner)
+		return dummy_handle;
+	current->in_page_owner = 1;
+
+	nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
+	handle = stack_depot_save(entries, nr_entries, flags);
+	if (!handle)
+		handle = failure_handle;
+
+	current->in_page_owner = 0;
+	return handle;
+}
+
+void __reset_page_owner(struct page *page, unsigned short order)
+{
+	int i;
+	struct page_ext *page_ext;
+	depot_stack_handle_t handle;
+	struct page_owner *page_owner;
+	u64 free_ts_nsec = local_clock();
+
+	page_ext = page_ext_get(page);
+	if (unlikely(!page_ext))
+		return;
+
+	handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
+	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_owner->free_ts_nsec = free_ts_nsec;
+		page_ext = page_ext_next(page_ext);
+	}
+	page_ext_put(page_ext);
+}
+
+static inline void __set_page_owner_handle(struct page_ext *page_ext,
+					depot_stack_handle_t handle,
+					unsigned short order, gfp_t gfp_mask)
+{
+	struct page_owner *page_owner;
+	int i;
+	u64 ts_nsec = local_clock();
+
+	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;
+		page_owner->pid = current->pid;
+		page_owner->tgid = current->tgid;
+		page_owner->ts_nsec = ts_nsec;
+		strscpy(page_owner->comm, current->comm,
+			sizeof(page_owner->comm));
+		__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 short order,
+					gfp_t gfp_mask)
+{
+	struct page_ext *page_ext;
+	depot_stack_handle_t handle;
+
+	handle = save_stack(gfp_mask);
+
+	page_ext = page_ext_get(page);
+	if (unlikely(!page_ext))
+		return;
+	__set_page_owner_handle(page_ext, handle, order, gfp_mask);
+	page_ext_put(page_ext);
+}
+
+void __set_page_owner_migrate_reason(struct page *page, int reason)
+{
+	struct page_ext *page_ext = page_ext_get(page);
+	struct page_owner *page_owner;
+
+	if (unlikely(!page_ext))
+		return;
+
+	page_owner = get_page_owner(page_ext);
+	page_owner->last_migrate_reason = reason;
+	page_ext_put(page_ext);
+}
+
+void __split_page_owner(struct page *page, unsigned int nr)
+{
+	int i;
+	struct page_ext *page_ext = page_ext_get(page);
+	struct page_owner *page_owner;
+
+	if (unlikely(!page_ext))
+		return;
+
+	for (i = 0; i < nr; i++) {
+		page_owner = get_page_owner(page_ext);
+		page_owner->order = 0;
+		page_ext = page_ext_next(page_ext);
+	}
+	page_ext_put(page_ext);
+}
+
+void __folio_copy_owner(struct folio *newfolio, struct folio *old)
+{
+	struct page_ext *old_ext;
+	struct page_ext *new_ext;
+	struct page_owner *old_page_owner, *new_page_owner;
+
+	old_ext = page_ext_get(&old->page);
+	if (unlikely(!old_ext))
+		return;
+
+	new_ext = page_ext_get(&newfolio->page);
+	if (unlikely(!new_ext)) {
+		page_ext_put(old_ext);
+		return;
+	}
+
+	old_page_owner = get_page_owner(old_ext);
+	new_page_owner = get_page_owner(new_ext);
+	new_page_owner->order = old_page_owner->order;
+	new_page_owner->gfp_mask = old_page_owner->gfp_mask;
+	new_page_owner->last_migrate_reason =
+		old_page_owner->last_migrate_reason;
+	new_page_owner->handle = old_page_owner->handle;
+	new_page_owner->pid = old_page_owner->pid;
+	new_page_owner->tgid = old_page_owner->tgid;
+	new_page_owner->ts_nsec = old_page_owner->ts_nsec;
+	new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
+	strcpy(new_page_owner->comm, old_page_owner->comm);
+
+	/*
+	 * We don't clear the bit on the old folio as it's going to be freed
+	 * after migration. Until then, the info can be useful in case of
+	 * a bug, and the overall stats will be off a bit only temporarily.
+	 * Also, migrate_misplaced_transhuge_page() can still fail the
+	 * migration and then we want the old folio to retain the info. But
+	 * in that case we also don't need to explicitly clear the info from
+	 * the new page, which will be freed.
+	 */
+	__set_bit(PAGE_EXT_OWNER, &new_ext->flags);
+	__set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags);
+	page_ext_put(new_ext);
+	page_ext_put(old_ext);
+}
+
+void pagetypeinfo_showmixedcount_print(struct seq_file *m,
+				       pg_data_t *pgdat, struct zone *zone)
+{
+	struct page *page;
+	struct page_ext *page_ext;
+	struct page_owner *page_owner;
+	unsigned long pfn, block_end_pfn;
+	unsigned long end_pfn = zone_end_pfn(zone);
+	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; ) {
+		page = pfn_to_online_page(pfn);
+		if (!page) {
+			pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
+			continue;
+		}
+
+		block_end_pfn = pageblock_end_pfn(pfn);
+		block_end_pfn = min(block_end_pfn, end_pfn);
+
+		pageblock_mt = get_pageblock_migratetype(page);
+
+		for (; pfn < block_end_pfn; pfn++) {
+			/* The pageblock is online, no need to recheck. */
+			page = pfn_to_page(pfn);
+
+			if (page_zone(page) != zone)
+				continue;
+
+			if (PageBuddy(page)) {
+				unsigned long freepage_order;
+
+				freepage_order = buddy_order_unsafe(page);
+				if (freepage_order <= MAX_ORDER)
+					pfn += (1UL << freepage_order) - 1;
+				continue;
+			}
+
+			if (PageReserved(page))
+				continue;
+
+			page_ext = page_ext_get(page);
+			if (unlikely(!page_ext))
+				continue;
+
+			if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
+				goto ext_put_continue;
+
+			page_owner = get_page_owner(page_ext);
+			page_mt = gfp_migratetype(page_owner->gfp_mask);
+			if (pageblock_mt != page_mt) {
+				if (is_migrate_cma(pageblock_mt))
+					count[MIGRATE_MOVABLE]++;
+				else
+					count[pageblock_mt]++;
+
+				pfn = block_end_pfn;
+				page_ext_put(page_ext);
+				break;
+			}
+			pfn += (1UL << page_owner->order) - 1;
+ext_put_continue:
+			page_ext_put(page_ext);
+		}
+	}
+
+	/* 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');
+}
+
+/*
+ * Looking for memcg information and print it out
+ */
+static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
+					 struct page *page)
+{
+#ifdef CONFIG_MEMCG
+	unsigned long memcg_data;
+	struct mem_cgroup *memcg;
+	bool online;
+	char name[80];
+
+	rcu_read_lock();
+	memcg_data = READ_ONCE(page->memcg_data);
+	if (!memcg_data)
+		goto out_unlock;
+
+	if (memcg_data & MEMCG_DATA_OBJCGS)
+		ret += scnprintf(kbuf + ret, count - ret,
+				"Slab cache page\n");
+
+	memcg = page_memcg_check(page);
+	if (!memcg)
+		goto out_unlock;
+
+	online = (memcg->css.flags & CSS_ONLINE);
+	cgroup_name(memcg->css.cgroup, name, sizeof(name));
+	ret += scnprintf(kbuf + ret, count - ret,
+			"Charged %sto %smemcg %s\n",
+			PageMemcgKmem(page) ? "(via objcg) " : "",
+			online ? "" : "offline ",
+			name);
+out_unlock:
+	rcu_read_unlock();
+#endif /* CONFIG_MEMCG */
+
+	return ret;
+}
+
+static ssize_t
+print_page_owner(char __user *buf, size_t count, unsigned long pfn,
+		struct page *page, struct page_owner *page_owner,
+		depot_stack_handle_t handle)
+{
+	int ret, pageblock_mt, page_mt;
+	char *kbuf;
+
+	count = min_t(size_t, count, PAGE_SIZE);
+	kbuf = kmalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	ret = scnprintf(kbuf, count,
+			"Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n",
+			page_owner->order, page_owner->gfp_mask,
+			&page_owner->gfp_mask, page_owner->pid,
+			page_owner->tgid, page_owner->comm,
+			page_owner->ts_nsec, page_owner->free_ts_nsec);
+
+	/* Print information relevant to grouping pages by mobility */
+	pageblock_mt = get_pageblock_migratetype(page);
+	page_mt  = gfp_migratetype(page_owner->gfp_mask);
+	ret += scnprintf(kbuf + ret, count - ret,
+			"PFN 0x%lx type %s Block %lu type %s Flags %pGp\n",
+			pfn,
+			migratetype_names[page_mt],
+			pfn >> pageblock_order,
+			migratetype_names[pageblock_mt],
+			&page->flags);
+
+	ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0);
+	if (ret >= count)
+		goto err;
+
+	if (page_owner->last_migrate_reason != -1) {
+		ret += scnprintf(kbuf + ret, count - ret,
+			"Page has been migrated, last migrate reason: %s\n",
+			migrate_reason_names[page_owner->last_migrate_reason]);
+	}
+
+	ret = print_page_owner_memcg(kbuf, count, ret, page);
+
+	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;
+}
+
+void __dump_page_owner(const struct page *page)
+{
+	struct page_ext *page_ext = page_ext_get((void *)page);
+	struct page_owner *page_owner;
+	depot_stack_handle_t handle;
+	gfp_t gfp_mask;
+	int mt;
+
+	if (unlikely(!page_ext)) {
+		pr_alert("There is not page extension available.\n");
+		return;
+	}
+
+	page_owner = get_page_owner(page_ext);
+	gfp_mask = page_owner->gfp_mask;
+	mt = gfp_migratetype(gfp_mask);
+
+	if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
+		pr_alert("page_owner info is not present (never set?)\n");
+		page_ext_put(page_ext);
+		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), pid %d, tgid %d (%s), ts %llu, free_ts %llu\n",
+		 page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask,
+		 page_owner->pid, page_owner->tgid, page_owner->comm,
+		 page_owner->ts_nsec, page_owner->free_ts_nsec);
+
+	handle = READ_ONCE(page_owner->handle);
+	if (!handle)
+		pr_alert("page_owner allocation stack trace missing\n");
+	else
+		stack_depot_print(handle);
+
+	handle = READ_ONCE(page_owner->free_handle);
+	if (!handle) {
+		pr_alert("page_owner free stack trace missing\n");
+	} else {
+		pr_alert("page last free stack trace:\n");
+		stack_depot_print(handle);
+	}
+
+	if (page_owner->last_migrate_reason != -1)
+		pr_alert("page has been migrated, last migrate reason: %s\n",
+			migrate_reason_names[page_owner->last_migrate_reason]);
+	page_ext_put(page_ext);
+}
+
+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;
+	struct page_owner *page_owner;
+	depot_stack_handle_t handle;
+
+	if (!static_branch_unlikely(&page_owner_inited))
+		return -EINVAL;
+
+	page = NULL;
+	if (*ppos == 0)
+		pfn = min_low_pfn;
+	else
+		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++;
+
+	/* Find an allocated page */
+	for (; pfn < max_pfn; pfn++) {
+		/*
+		 * This temporary page_owner is required so
+		 * that we can avoid the context switches while holding
+		 * the rcu lock and copying the page owner information to
+		 * user through copy_to_user() or GFP_KERNEL allocations.
+		 */
+		struct page_owner page_owner_tmp;
+
+		/*
+		 * 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;
+		}
+
+		page = pfn_to_page(pfn);
+		if (PageBuddy(page)) {
+			unsigned long freepage_order = buddy_order_unsafe(page);
+
+			if (freepage_order <= MAX_ORDER)
+				pfn += (1UL << freepage_order) - 1;
+			continue;
+		}
+
+		page_ext = page_ext_get(page);
+		if (unlikely(!page_ext))
+			continue;
+
+		/*
+		 * Some pages could be missed by concurrent allocation or free,
+		 * because we don't hold the zone lock.
+		 */
+		if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
+			goto ext_put_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))
+			goto ext_put_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))
+			goto ext_put_continue;
+
+		/*
+		 * Access to page_ext->handle isn't synchronous so we should
+		 * be careful to access it.
+		 */
+		handle = READ_ONCE(page_owner->handle);
+		if (!handle)
+			goto ext_put_continue;
+
+		/* Record the next PFN to read in the file offset */
+		*ppos = pfn + 1;
+
+		page_owner_tmp = *page_owner;
+		page_ext_put(page_ext);
+		return print_page_owner(buf, count, pfn, page,
+				&page_owner_tmp, handle);
+ext_put_continue:
+		page_ext_put(page_ext);
+	}
+
+	return 0;
+}
+
+static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
+{
+	switch (orig) {
+	case SEEK_SET:
+		file->f_pos = offset;
+		break;
+	case SEEK_CUR:
+		file->f_pos += offset;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return file->f_pos;
+}
+
+static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
+{
+	unsigned long pfn = zone->zone_start_pfn;
+	unsigned long end_pfn = zone_end_pfn(zone);
+	unsigned long count = 0;
+
+	/*
+	 * 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; ) {
+		unsigned long block_end_pfn;
+
+		if (!pfn_valid(pfn)) {
+			pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
+			continue;
+		}
+
+		block_end_pfn = pageblock_end_pfn(pfn);
+		block_end_pfn = min(block_end_pfn, end_pfn);
+
+		for (; pfn < block_end_pfn; pfn++) {
+			struct page *page = pfn_to_page(pfn);
+			struct page_ext *page_ext;
+
+			if (page_zone(page) != zone)
+				continue;
+
+			/*
+			 * To avoid having to grab zone->lock, be a little
+			 * careful when reading buddy page order. The only
+			 * danger is that we skip too much and potentially miss
+			 * some early allocated pages, which is better than
+			 * heavy lock contention.
+			 */
+			if (PageBuddy(page)) {
+				unsigned long order = buddy_order_unsafe(page);
+
+				if (order > 0 && order <= MAX_ORDER)
+					pfn += (1UL << order) - 1;
+				continue;
+			}
+
+			if (PageReserved(page))
+				continue;
+
+			page_ext = page_ext_get(page);
+			if (unlikely(!page_ext))
+				continue;
+
+			/* Maybe overlapping zone */
+			if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
+				goto ext_put_continue;
+
+			/* Found early allocated page */
+			__set_page_owner_handle(page_ext, early_handle,
+						0, 0);
+			count++;
+ext_put_continue:
+			page_ext_put(page_ext);
+		}
+		cond_resched();
+	}
+
+	pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
+		pgdat->node_id, zone->name, count);
+}
+
+static void init_zones_in_node(pg_data_t *pgdat)
+{
+	struct zone *zone;
+	struct zone *node_zones = pgdat->node_zones;
+
+	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
+		if (!populated_zone(zone))
+			continue;
+
+		init_pages_in_zone(pgdat, zone);
+	}
+}
+
+static void init_early_allocated_pages(void)
+{
+	pg_data_t *pgdat;
+
+	for_each_online_pgdat(pgdat)
+		init_zones_in_node(pgdat);
+}
+
+static const struct file_operations proc_page_owner_operations = {
+	.read		= read_page_owner,
+	.llseek		= lseek_page_owner,
+};
+
+static int __init pageowner_init(void)
+{
+	if (!static_branch_unlikely(&page_owner_inited)) {
+		pr_info("page_owner is disabled\n");
+		return 0;
+	}
+
+	debugfs_create_file("page_owner", 0400, NULL, NULL,
+			    &proc_page_owner_operations);
+
+	return 0;
+}
+late_initcall(pageowner_init)