From: Wathsala Vithanage <wathsala.vithanage@arm.com>
To: honnappa.nagarahalli@arm.com, konstantin.v.ananyev@yandex.ru,
thomas@monjalon.net, ruifeng.wang@arm.com
Cc: dev@dpdk.org, nd@arm.com,
Wathsala Vithanage <wathsala.vithanage@arm.com>
Subject: [RFC] ring: remove unnecessary fences in C11 ring for performance
Date: Mon, 12 Jun 2023 19:47:16 +0000 [thread overview]
Message-ID: <20230612194716.1050379-2-wathsala.vithanage@arm.com> (raw)
In-Reply-To: <20230612194716.1050379-1-wathsala.vithanage@arm.com>
For improved performance over the current C11 based ring
implementation, two ACQUIRE fences between the load of the old_head
and the load of the const_tail in __rte_ring_move_prod_head and the
load of old_head and load of the prod_tail in
__rte_ring_move_cons_head functions have been removed. These two
fences are not required for the safety of the ring library.
Signed-off-by: Wathsala Vithanage <wathsala.vithanage@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
.mailmap | 1 +
lib/ring/rte_ring_c11_pvt.h | 6 ------
2 files changed, 1 insertion(+), 6 deletions(-)
diff --git a/.mailmap b/.mailmap
index 4018f0fc47..367115d134 100644
--- a/.mailmap
+++ b/.mailmap
@@ -1430,6 +1430,7 @@ Walter Heymans <walter.heymans@corigine.com>
Wang Sheng-Hui <shhuiw@gmail.com>
Wangyu (Eric) <seven.wangyu@huawei.com>
Waterman Cao <waterman.cao@intel.com>
+Wathsala Vithanage <wathsala.vithanage@arm.com>
Weichun Chen <weichunx.chen@intel.com>
Wei Dai <wei.dai@intel.com>
Weifeng Li <liweifeng96@126.com>
diff --git a/lib/ring/rte_ring_c11_pvt.h b/lib/ring/rte_ring_c11_pvt.h
index f895950df4..eb59c61b6a 100644
--- a/lib/ring/rte_ring_c11_pvt.h
+++ b/lib/ring/rte_ring_c11_pvt.h
@@ -66,9 +66,6 @@ __rte_ring_move_prod_head(struct rte_ring *r, unsigned int is_sp,
/* Reset n to the initial burst count */
n = max;
- /* Ensure the head is read before tail */
- __atomic_thread_fence(__ATOMIC_ACQUIRE);
-
/* load-acquire synchronize with store-release of ht->tail
* in update_tail.
*/
@@ -142,9 +139,6 @@ __rte_ring_move_cons_head(struct rte_ring *r, int is_sc,
/* Restore n as it may change every loop */
n = max;
- /* Ensure the head is read before tail */
- __atomic_thread_fence(__ATOMIC_ACQUIRE);
-
/* this load-acquire synchronize with store-release of ht->tail
* in update_tail.
*/
--
2.25.1
prev parent reply other threads:[~2023-06-12 19:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-12 19:47 Wathsala Vithanage
2023-06-12 19:47 ` Wathsala Vithanage [this message]
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