[dpdk-dev] [PATCH 06/14] eal: mp: end the multiprocess thread during cleanup

[Stephen Hemminger]

When rte_eal_cleanup is called, all control threads should exit.
For the mp thread, this best handled by closing the mp_socket
and letting the thread see that.

This also fixes potential problems where the mp_socket gets
another hard error, and the thread runs away repeating itself
by reading the same error.

Fixes: 85d6815fa6d0 ("eal: close multi-process socket during cleanup")
Cc: qi.z.zh...@intel.com
Cc: sta...@dpdk.org
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
---
 lib/librte_eal/common/eal_common_proc.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_proc.c 
b/lib/librte_eal/common/eal_common_proc.c
index 935e8fefeba8..f369d8bf6dd8 100644
--- a/lib/librte_eal/common/eal_common_proc.c
+++ b/lib/librte_eal/common/eal_common_proc.c
@@ -276,8 +276,17 @@ read_msg(struct mp_msg_internal *m, struct sockaddr_un *s)
        msgh.msg_control = control;
        msgh.msg_controllen = sizeof(control);
 
+retry:
        msglen = recvmsg(mp_fd, &msgh, 0);
+
+       /* zero length message means socket was closed */
+       if (msglen == 0)
+               return 0;
+
        if (msglen < 0) {
+               if (errno == EINTR)
+                       goto retry;
+
                RTE_LOG(ERR, EAL, "recvmsg failed, %s\n", strerror(errno));
                return -1;
        }
@@ -305,7 +314,7 @@ read_msg(struct mp_msg_internal *m, struct sockaddr_un *s)
                RTE_LOG(ERR, EAL, "invalid received data length\n");
                return -1;
        }
-       return 0;
+       return msglen;
 }
 
 static void
@@ -376,10 +385,8 @@ mp_handle(void *arg __rte_unused)
        struct mp_msg_internal msg;
        struct sockaddr_un sa;
 
-       while (1) {
-               if (read_msg(&msg, &sa) == 0)
-                       process_msg(&msg, &sa);
-       }
+       while (read_msg(&msg, &sa) > 0)
+               process_msg(&msg, &sa);
 
        return NULL;
 }
-- 
2.20.1