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From: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
To: olivier.matz@6wind.com
Cc: dev@dpdk.org, Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Subject: [dpdk-dev] [PATCH] rte_ring: clarify preemptable nature of ring algorithm
Date: Tue, 29 May 2018 00:06:13 -0500	[thread overview]
Message-ID: <1527570373-120745-1-git-send-email-honnappa.nagarahalli@arm.com> (raw)

rte_ring implementation is not preemptable only under certain circumstances.
This clarification is helpful for data plane and control plane communication
using rte_ring.

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
---
 lib/librte_ring/rte_ring.h | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
index d3d3f7f..2f9c945 100644
--- a/lib/librte_ring/rte_ring.h
+++ b/lib/librte_ring/rte_ring.h
@@ -26,8 +26,13 @@
  * - Bulk dequeue.
  * - Bulk enqueue.
  *
- * Note: the ring implementation is not preemptable. A lcore must not
- * be interrupted by another task that uses the same ring.
+ * Note: the ring implementation can block threads from completing their
+ * operation under the following circumstances.
+ * A preempted thread can block other threads (operating on the same ring)
+ * from completing their operations, only if those threads are performing
+ * the same ring operation (enqueue/dequeue) as the preempted thread.
+ * In other words, a preempted consumer thread will not block any producer
+ * threads and vice versa.
  *
  */
 
-- 
2.7.4

             reply	other threads:[~2018-05-29  5:06 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-29  5:06 Honnappa Nagarahalli [this message]
2018-05-30  2:39 ` Stephen Hemminger
2018-05-30  4:32   ` Honnappa Nagarahalli

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