+ int reserve_cpu; /* processor id updated by the reserve */
+ size_t slot_size; /* size of the reserved slot */
+ unsigned long buf_offset; /* offset following the record header */
+ unsigned long pre_offset; /*
+ * Initial offset position _before_
+ * the record is written. Positioned
+ * prior to record header alignment
+ * padding.
+ */
+ uint64_t tsc; /* time-stamp counter value */
+ unsigned int rflags; /* reservation flags */
+ void *ip; /* caller ip address */
+