fop: document M0_FOP_TYPE_INIT2()
@@ -308,6 +308,11 @@ void m0_fop_type_init(struct m0_fop_type *ft,
m0_fop_type_init((ft), &(const struct __m0_fop_type_init_args) { \
__VA_ARGS__ });
+/**
+ * This variant of M0_FOP_TYPE_INIT() re-uses the same __args object in
+ * each M0_FOP_TYPE_INIT2() call instead of creating the new one on stack
+ * bloating its size (which may not overstep the 1K limit in kernel).
+ */
#define M0_FOP_TYPE_INIT2_DECL struct __m0_fop_type_init_args __args
#define M0_FOP_TYPE_INIT2(ft, ...) ({ \
__args = (struct __m0_fop_type_init_args) {__VA_ARGS__}; \
