+ if (f->ooos_newest == OOO_SEGMENT_INVALID_INDEX)
+ return 0;
+ return pool_elt_at_index (f->ooo_segments, f->ooos_newest);
+}
+
+always_inline u32
+ooo_segment_distance_to_tail (svm_fifo_t * f, u32 a)
+{
+ /* Ambiguous. Assumption is that ooo segments don't touch tail */
+ if (a == f->tail && f->tail == f->head)
+ return f->nitems;
+
+ return ((f->nitems + a - f->tail) % f->nitems);