svm_fifo_t *fifos; /**< Linked list of active RX fifos */
svm_fifo_t *free_fifos; /**< Freelists by fifo size */
svm_fifo_chunk_t **free_chunks; /**< Freelists by chunk size */
+ u32 *num_chunks; /**< Allocated chunks by chunk size */
uword n_fl_chunk_bytes; /**< Chunk bytes on freelist */
uword virtual_mem; /**< Slice sum of all fifo sizes */
clib_spinlock_t chunk_lock;