[PATCHv7 03/14] mm: Report unaccepted memory in meminfo

[Kirill A. Shutemov]

Track amount of unaccepted memory and report it in /proc/meminfo and in
node meminfo.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 drivers/base/node.c    | 7 +++++++
 fs/proc/meminfo.c      | 5 +++++
 include/linux/mmzone.h | 1 +
 mm/page_alloc.c        | 9 ++++++++-
 mm/vmstat.c            | 1 +
 5 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 0ac6376ef7a1..fc7cf4d91eb6 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -446,6 +446,9 @@ static ssize_t node_read_meminfo(struct device *dev,
 			     "Node %d ShmemPmdMapped: %8lu kB\n"
 			     "Node %d FileHugePages: %8lu kB\n"
 			     "Node %d FilePmdMapped: %8lu kB\n"
+#endif
+#ifdef CONFIG_UNACCEPTED_MEMORY
+			     "Node %d UnacceptedPages: %8lu kB\n"
 #endif
 			     ,
 			     nid, K(node_page_state(pgdat, NR_FILE_DIRTY)),
@@ -474,6 +477,10 @@ static ssize_t node_read_meminfo(struct device *dev,
 			     nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
 			     nid, K(node_page_state(pgdat, NR_FILE_THPS)),
 			     nid, K(node_page_state(pgdat, NR_FILE_PMDMAPPED))
+#endif
+#ifdef CONFIG_UNACCEPTED_MEMORY
+			     ,
+			     nid, K(node_page_state(pgdat, NR_UNACCEPTED))
 #endif
 			    );
 	len += hugetlb_report_node_meminfo(buf, len, nid);
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 6e89f0e2fd20..796544e50365 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -153,6 +153,11 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 		    global_zone_page_state(NR_FREE_CMA_PAGES));
 #endif
 
+#ifdef CONFIG_UNACCEPTED_MEMORY
+	show_val_kb(m, "UnacceptedPages:",
+		    global_node_page_state(NR_UNACCEPTED));
+#endif
+
 	hugetlb_report_meminfo(m);
 
 	arch_report_meminfo(m);
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index aab70355d64f..aa08cd7eaaf5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -212,6 +212,7 @@ enum node_stat_item {
 	NR_FOLL_PIN_ACQUIRED,	/* via: pin_user_page(), gup flag: FOLL_PIN */
 	NR_FOLL_PIN_RELEASED,	/* pages returned via unpin_user_page() */
 	NR_KERNEL_STACK_KB,	/* measured in KiB */
+	NR_UNACCEPTED,
 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
 	NR_KERNEL_SCS_KB,	/* measured in KiB */
 #endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 279c2746aaa8..6316d695a567 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1012,6 +1012,7 @@ static void accept_page(struct page *page, unsigned int order)
 
 	accept_memory(start, start + (PAGE_SIZE << order));
 	__ClearPageUnaccepted(page);
+	mod_node_page_state(page_pgdat(page), NR_UNACCEPTED, -(1 << order));
 
 	/* Assert that there is no PageUnaccepted() on tail pages */
 	if (IS_ENABLED(CONFIG_DEBUG_VM)) {
@@ -1063,6 +1064,7 @@ static inline void __free_one_page(struct page *page,
 	struct page *buddy;
 	bool to_tail;
 	bool page_needs_acceptance = false;
+	int nr_unaccepted = 0;
 
 	VM_BUG_ON(!zone_is_initialized(zone));
 	VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page);
@@ -1076,6 +1078,7 @@ static inline void __free_one_page(struct page *page,
 
 	if (PageUnaccepted(page)) {
 		page_needs_acceptance = true;
+		nr_unaccepted += 1 << order;
 		__ClearPageUnaccepted(page);
 	}
 
@@ -1117,6 +1120,7 @@ static inline void __free_one_page(struct page *page,
 		/* Mark page unaccepted if any of merged pages were unaccepted */
 		if (PageUnaccepted(buddy)) {
 			page_needs_acceptance = true;
+			nr_unaccepted += 1 << order;
 			__ClearPageUnaccepted(buddy);
 		}
 
@@ -1143,8 +1147,11 @@ static inline void __free_one_page(struct page *page,
 	 */
 	if (!page_needs_acceptance && (fpi_flags & FPI_UNACCEPTED_SLOWPATH))
 		page_needs_acceptance = page_contains_unaccepted(page, order);
-	if (page_needs_acceptance)
+	if (page_needs_acceptance) {
 		__SetPageUnaccepted(page);
+		__mod_node_page_state(page_pgdat(page), NR_UNACCEPTED,
+				    (1 << order) - nr_unaccepted);
+	}
 
 	if (fpi_flags & FPI_TO_TAIL)
 		to_tail = true;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 373d2730fcf2..4e12d22f1e04 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1236,6 +1236,7 @@ const char * const vmstat_text[] = {
 	"nr_foll_pin_acquired",
 	"nr_foll_pin_released",
 	"nr_kernel_stack",
+	"nr_unaccepted",
 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
 	"nr_shadow_call_stack",
 #endif
-- 
2.35.1