19.03.2021 15:44, Dmitry Osipenko пишет:
...

quoted

 #include <linux/debugfs.h>
+#include <linux/kobject.h>
+
+struct cma_stat {
+	spinlock_t lock;
+	/* the number of CMA page successful allocations */
+	unsigned long nr_pages_succeeded;
+	/* the number of CMA page allocation failures */
+	unsigned long nr_pages_failed;
+	struct kobject kobj;
+};
 
 struct cma {
 	unsigned long   base_pfn;

@@ -16,6 +26,9 @@ struct cma {
 	struct debugfs_u32_array dfs_bitmap;
 #endif
 	char name[CMA_MAX_NAME];
+#ifdef CONFIG_CMA_SYSFS
+	struct cma_stat	*stat;
+#endif

What is the point of allocating stat dynamically?

...

quoted

+void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count)
+{
+	spin_lock(&cma->stat->lock);
+	cma->stat->nr_pages_succeeded += count;
+	spin_unlock(&cma->stat->lock);
+}
+
+void cma_sysfs_fail_pages_count(struct cma *cma, size_t count)
+{
+	spin_lock(&cma->stat->lock);
+	cma->stat->nr_pages_failed += count;
+	spin_unlock(&cma->stat->lock);
+}

You could use atomic increment and then locking isn't needed.