From ecc7d10e448e91d01b821499baa755ca6a92115b Mon Sep 17 00:00:00 2001 From: Juhamatti Kuusisaari Date: Fri, 15 Jul 2016 07:39:51 +0300 Subject: [PATCH 1/1] ring: guarantee dequeue ordering before tail update Consumer queue dequeuing must be guaranteed to be done fully before the tail is updated. This is not guaranteed with a read barrier, changed to a write barrier just before tail update which in practice guarantees correct order of reads and writes. Signed-off-by: Juhamatti Kuusisaari Acked-by: Konstantin Ananyev --- lib/librte_ring/rte_ring.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h index 0e22e6946f..f928324d95 100644 --- a/lib/librte_ring/rte_ring.h +++ b/lib/librte_ring/rte_ring.h @@ -756,7 +756,7 @@ __rte_ring_sc_do_dequeue(struct rte_ring *r, void **obj_table, /* copy in table */ DEQUEUE_PTRS(); - rte_smp_rmb(); + rte_smp_wmb(); __RING_STAT_ADD(r, deq_success, n); r->cons.tail = cons_next; -- 2.20.1