kfifo_size
*val = kfifo_size(&counter->events);
equeue->sz = kfifo_size(&equeue->kfifo);
if (kfifo_size(&kf->kf) < 1)
int kfifo_size =
status = kfifo_alloc(&rt2x00dev->txstatus_fifo, kfifo_size,
unsigned int __avail = kfifo_size(__tmpq) - kfifo_len(__tmpq); \
printk(KERN_INFO "queue size: %u\n", kfifo_size(&fifo));
l = min(len, kfifo_size(fifo) - off);