[dpdk-stable] [PATCH v1] lib/distributor: fix livelock issue on flush

[David Hunt]

The Distributor autotest can lock if ran enough times. Worker and
distributir threads get into a livelock situation waiting on each
other.
Issue first encountered my RedHat in Travis CI
https://bugs.dpdk.org/show_bug.cgi?id=316

To repeat:
`while sudo sh -c "echo 'distributor_autotest' |
		./build/app/test/dpdk-test"; do :; done`

The root cause is where we are flushing on exit, and do not wait for
all worker packets to be returned before exiting.
Add a delay on flush so that all worker packets are returned before
completing the flush.

Bugzilla ID: 316
Fixes: 775003ad2f96 ("distributor: add new burst-capable library")
Cc: stable at dpdk.org

Tested-by: Michael Santana <msantana at redhat.com>
Signed-off-by: David Hunt <david.hunt at intel.com>
---
 lib/librte_distributor/rte_distributor.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/librte_distributor/rte_distributor.c b/lib/librte_distributor/rte_distributor.c
index 9fa05f69a..21eb1fb0a 100644
--- a/lib/librte_distributor/rte_distributor.c
+++ b/lib/librte_distributor/rte_distributor.c
@@ -542,6 +542,9 @@ rte_distributor_flush_v1705(struct rte_distributor *d)
 	while (total_outstanding(d) > 0)
 		rte_distributor_process(d, NULL, 0);
 
+	/* wait 10ms to allow all worker drain the pkts */
+	rte_delay_us(10000);
+
 	/*
 	 * Send empty burst to all workers to allow them to exit
 	 * gracefully, should they need to.
-- 
2.17.1