shmem: Count and show reliable shmem info

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA

--------------------------------

Count reliable shmem usage based on NR_SHMEM.
Add ReliableShmem in /proc/meminfo to show reliable memory info
used by shmem.

- ReliableShmem: reliable memory used by shmem
Signed-off-by: NZhou Guanghui <zhouguanghui1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>

Documentation/filesystems/proc.rst

@@ -972,6 +972,7 @@ varies by architecture and compile options.  The following is from a
     ReliableTotal: 7340032 kB
     ReliableUsed:   418824 kB
     ReliableBuddyMem: 418824 kB
+    ReliableShmem:        96 kB
 
 MemTotal
               Total usable RAM (i.e. physical RAM minus a few reserved
@@ -1107,6 +1108,8 @@ ReliableUsed
               The used amount of reliable memory
 ReliableBuddyMem
               Size of unused mirrored memory in buddy system
+ReliableShmem
+              Total reliable memory used by share memory
 
 vmallocinfo
 ~~~~~~~~~~~

include/linux/mem_reliable.h

@@ -16,6 +16,7 @@ DECLARE_STATIC_KEY_FALSE(mem_reliable);
 
 extern bool reliable_enabled;
 extern bool shmem_reliable;
+extern struct percpu_counter reliable_shmem_used_nr_page;
 extern bool reliable_allow_fallback;
 extern bool pagecache_use_reliable_mem;
 extern struct percpu_counter pagecache_reliable_pages;
@@ -81,6 +82,12 @@ static inline bool page_reliable(struct page *page)
 	return page_zonenum(page) < ZONE_MOVABLE;
 }
 
+static inline void shmem_reliable_page_counter(struct page *page, int nr_page)
+{
+	if (shmem_reliable_is_enabled() && page_reliable(page))
+		percpu_counter_add(&reliable_shmem_used_nr_page, nr_page);
+}
+
 static inline u64 task_reliable_used_pages(void)
 {
 	s64 nr_pages;
@@ -126,6 +133,8 @@ static inline bool skip_none_movable_zone(gfp_t gfp, struct zoneref *z)
 }
 static inline void reliable_report_meminfo(struct seq_file *m) {}
 static inline bool shmem_reliable_is_enabled(void) { return false; }
+static inline void shmem_reliable_page_counter(struct page *page,
+					       int nr_page) {}
 static inline void page_cache_prepare_alloc(gfp_t *gfp) {}
 static inline bool mem_reliable_status(void) { return false; }
 static inline bool page_reliable(struct page *page) { return false; }

mm/filemap.c

@@ -192,6 +192,7 @@ static void unaccount_page_cache_page(struct address_space *mapping,
 	__mod_lruvec_page_state(page, NR_FILE_PAGES, -nr);
 	if (PageSwapBacked(page)) {
 		__mod_lruvec_page_state(page, NR_SHMEM, -nr);
+		shmem_reliable_page_counter(page, -nr);
 		if (PageTransHuge(page))
 			__dec_node_page_state(page, NR_SHMEM_THPS);
 	} else if (PageTransHuge(page)) {
@@ -800,10 +801,14 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 		__dec_lruvec_page_state(old, NR_FILE_PAGES);
 	if (!PageHuge(new))
 		__inc_lruvec_page_state(new, NR_FILE_PAGES);
-	if (PageSwapBacked(old))
+	if (PageSwapBacked(old)) {
 		__dec_lruvec_page_state(old, NR_SHMEM);
-	if (PageSwapBacked(new))
+		shmem_reliable_page_counter(old, -1);
+	}
+	if (PageSwapBacked(new)) {
 		__inc_lruvec_page_state(new, NR_SHMEM);
+		shmem_reliable_page_counter(new, 1);
+	}
 	xas_unlock_irqrestore(&xas, flags);
 	if (freepage)
 		freepage(old);

mm/khugepaged.c

@@ -1910,6 +1910,8 @@ static void collapse_file(struct mm_struct *mm,
 			ClearPageActive(page);
 			ClearPageUnevictable(page);
 			unlock_page(page);
+			if (is_shmem)
+				shmem_reliable_page_counter(page, -1);
 			put_page(page);
 			index++;
 		}
@@ -1920,8 +1922,10 @@ static void collapse_file(struct mm_struct *mm,
 
 		SetPageUptodate(new_page);
 		page_ref_add(new_page, HPAGE_PMD_NR - 1);
-		if (is_shmem)
+		if (is_shmem) {
 			set_page_dirty(new_page);
+			shmem_reliable_page_counter(new_page, 1 << HPAGE_PMD_ORDER);
+		}
 		lru_cache_add(new_page);
 
 		/*

mm/mem_reliable.c

@@ -16,6 +16,7 @@ EXPORT_SYMBOL_GPL(mem_reliable);
 
 bool reliable_enabled;
 bool shmem_reliable __read_mostly = true;
+struct percpu_counter reliable_shmem_used_nr_page;
 bool reliable_allow_fallback __read_mostly = true;
 bool pagecache_use_reliable_mem __read_mostly = true;
 struct percpu_counter pagecache_reliable_pages;
@@ -147,8 +148,12 @@ void mem_reliable_init(bool has_unmirrored_mem, unsigned long *zone_movable_pfn,
 
 void shmem_reliable_init(void)
 {
-	if (!mem_reliable_is_enabled() || !shmem_reliable_is_enabled())
+	if (!mem_reliable_is_enabled() || !shmem_reliable_is_enabled()) {
 		shmem_reliable = false;
+		return;
+	}
+
+	percpu_counter_init(&reliable_shmem_used_nr_page, 0, GFP_KERNEL);
 }
 
 static void show_val_kb(struct seq_file *m, const char *s, unsigned long num)
@@ -166,6 +171,12 @@ void reliable_report_meminfo(struct seq_file *m)
 	show_val_kb(m, "ReliableUsed:     ", used_reliable_pages());
 	show_val_kb(m, "ReliableBuddyMem: ", free_reliable_pages());
 
+	if (shmem_reliable_is_enabled()) {
+		unsigned long shmem_pages = (unsigned long)percpu_counter_sum(
+			&reliable_shmem_used_nr_page);
+		show_val_kb(m, "ReliableShmem:    ", shmem_pages);
+	}
+
 	if (pagecache_reliable_is_enabled()) {
 		s64 nr_pagecache_pages = 0;
 		unsigned long num = 0;

mm/migrate.c

@@ -481,6 +481,11 @@ int migrate_page_move_mapping(struct address_space *mapping,
 	xas_unlock(&xas);
 	/* Leave irq disabled to prevent preemption while updating stats */
 
+	if (PageSwapBacked(page) && !PageSwapCache(page)) {
+		shmem_reliable_page_counter(page, -nr);
+		shmem_reliable_page_counter(newpage, nr);
+	}
+
 	/*
 	 * If moved to a different zone then also account
 	 * the page for that zone. Other VM counters will be

mm/shmem.c

@@ -752,6 +752,7 @@ static int shmem_add_to_page_cache(struct page *page,
 		mapping->nrpages += nr;
 		__mod_lruvec_page_state(page, NR_FILE_PAGES, nr);
 		__mod_lruvec_page_state(page, NR_SHMEM, nr);
+		shmem_reliable_page_counter(page, nr);
 unlock:
 		xas_unlock_irq(&xas);
 	} while (xas_nomem(&xas, gfp));
@@ -784,6 +785,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
 	mapping->nrpages--;
 	__dec_lruvec_page_state(page, NR_FILE_PAGES);
 	__dec_lruvec_page_state(page, NR_SHMEM);
+	shmem_reliable_page_counter(page, -1);
 	xa_unlock_irq(&mapping->i_pages);
 	put_page(page);
 	BUG_ON(error);