1 int
 2 rte_eal_intr_init(void)
 3 {
 4     int ret = 0;
 5
 6     /* init the global interrupt source head */
 7     TAILQ_INIT(&intr_sources);
 8
 9     /**
10      * create a pipe which will be waited by epoll and notified to
11      * rebuild the wait list of epoll.
12      */
13     if (pipe(intr_pipe.pipefd) < 0)
14         return -1;
15
16     /* create the host thread to wait/handle the interrupt */
17     ret = pthread_create(&intr_thread, NULL,
18             eal_intr_thread_main, NULL);
19     if (ret != 0)
20         RTE_LOG(ERR, EAL,
21             "Failed to create thread for interrupt handling\n");
22
23     return -ret;
24 }

 1 static __attribute__((noreturn)) void *
 2 eal_intr_thread_main(__rte_unused void *arg)
 3 {
 4     struct epoll_event ev;
 5
 6     /* host thread, never break out */
 7     for (;;) {
 8         /* build up the epoll fd with all descriptors we are to
 9          * wait on then pass it to the handle_interrupts function
10          */
11         static struct epoll_event pipe_event = {
12             .events = EPOLLIN | EPOLLPRI,
13         };
14         struct rte_intr_source *src;
15         unsigned numfds = 0;
16
17         /* create epoll fd */
18         int pfd = epoll_create(1);
19         if (pfd < 0)
20             rte_panic("Cannot create epoll instance\n");
21
22         pipe_event.data.fd = intr_pipe.readfd;
23         /**
24          * add pipe fd into wait list, this pipe is used to
25          * rebuild the wait list.
26          */
27         if (epoll_ctl(pfd, EPOLL_CTL_ADD, intr_pipe.readfd,
28                         &pipe_event) < 0) {
29             rte_panic("Error adding fd to %d epoll_ctl, %s\n",
30                     intr_pipe.readfd, strerror(errno));
31         }
32         numfds++;
33
34         rte_spinlock_lock(&intr_lock);
35
36         TAILQ_FOREACH(src, &intr_sources, next) {
37             if (src->callbacks.tqh_first == NULL)
38                 continue; /* skip those with no callbacks */
39             ev.events = EPOLLIN | EPOLLPRI;
40             ev.data.fd = src->intr_handle.fd;
41
42             /**
43              * add all the uio device file descriptor
44              * into wait list.
45              */
46             if (epoll_ctl(pfd, EPOLL_CTL_ADD,
47                     src->intr_handle.fd, &ev) < 0){
48                 rte_panic("Error adding fd %d epoll_ctl, %s\n",
49                     src->intr_handle.fd, strerror(errno));
50             }
51             else
52                 numfds++;
53         }
54         rte_spinlock_unlock(&intr_lock);
55         /* serve the interrupt */
56         eal_intr_handle_interrupts(pfd, numfds);
57
58         /**
59          * when we return, we need to rebuild the
60          * list of fds to monitor.
61          */
62         close(pfd);
63     }
64 }

1 rte_intr_callback_register(&(pci_dev->intr_handle),
2     eth_igb_interrupt_handler, (void *)eth_dev);

1 struct rte_intr_source {
2     TAILQ_ENTRY(rte_intr_source) next;
3     struct rte_intr_handle intr_handle; /**< interrupt handle */
4     struct rte_intr_cb_list callbacks;  /**< user callbacks */
5     uint32_t active;
6 };