+/**
+ * blkg_rwstat_merge - merge a blkg_rwstat into another
+ * @to: the destination blkg_rwstat
+ * @from: the source
+ *
+ * Add @from's counts to @to.
+ */
+static inline void blkg_rwstat_merge(struct blkg_rwstat *to,
+ struct blkg_rwstat *from)
+{
+ struct blkg_rwstat v = blkg_rwstat_read(from);
+ int i;
+
+ u64_stats_update_begin(&to->syncp);
+ for (i = 0; i < BLKG_RWSTAT_NR; i++)
+ to->cnt[i] += v.cnt[i];
+ u64_stats_update_end(&to->syncp);
+}
+