android: binder: Add page usage in binder stats

Add the number of active, lru, and free pages for
each binder process in binder stats

Signed-off-by: Sherry Yang <sherryy@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/android/binder.c

@@ -5047,6 +5047,8 @@ static void print_binder_proc_stats(struct seq_file *m,
 	count = binder_alloc_get_allocated_count(&proc->alloc);
 	seq_printf(m, "  buffers: %d\n", count);
 
+	binder_alloc_print_pages(m, &proc->alloc);
+
 	count = 0;
 	binder_inner_proc_lock(proc);
 	list_for_each_entry(w, &proc->todo, entry) {

drivers/android/binder_alloc.c

@@ -831,6 +831,34 @@ void binder_alloc_print_allocated(struct seq_file *m,
 	mutex_unlock(&alloc->mutex);
 }
 
+/**
+ * binder_alloc_print_pages() - print page usage
+ * @m:     seq_file for output via seq_printf()
+ * @alloc: binder_alloc for this proc
+ */
+void binder_alloc_print_pages(struct seq_file *m,
+			      struct binder_alloc *alloc)
+{
+	struct binder_lru_page *page;
+	int i;
+	int active = 0;
+	int lru = 0;
+	int free = 0;
+
+	mutex_lock(&alloc->mutex);
+	for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
+		page = &alloc->pages[i];
+		if (!page->page_ptr)
+			free++;
+		else if (list_empty(&page->lru))
+			active++;
+		else
+			lru++;
+	}
+	mutex_unlock(&alloc->mutex);
+	seq_printf(m, "  pages: %d:%d:%d\n", active, lru, free);
+}
+
 /**
  * binder_alloc_get_allocated_count() - return count of buffers
  * @alloc: binder_alloc for this proc

drivers/android/binder_alloc.h

@@ -142,6 +142,8 @@ extern void binder_alloc_deferred_release(struct binder_alloc *alloc);
 extern int binder_alloc_get_allocated_count(struct binder_alloc *alloc);
 extern void binder_alloc_print_allocated(struct seq_file *m,
 					 struct binder_alloc *alloc);
+void binder_alloc_print_pages(struct seq_file *m,
+			      struct binder_alloc *alloc);
 
 /**
  * binder_alloc_get_free_async_space() - get free space available for async