From: Ruifeng Wang <ruifeng.wang@arm.com>
To: thomas@monjalon.net, david.marchand@redhat.com
Cc: dev@dpdk.org, roretzla@linux.microsoft.com,
hofors@lysator.liu.se, konstantin.v.ananyev@yandex.ru,
honnappa.nagarahalli@arm.com, nd@arm.com,
Ruifeng Wang <ruifeng.wang@arm.com>
Subject: [PATCH v3] eal: add notes to SMP memory barrier APIs
Date: Mon, 3 Jul 2023 17:56:42 +0800 [thread overview]
Message-ID: <20230703095642.3326601-1-ruifeng.wang@arm.com> (raw)
In-Reply-To: <20230621064420.163931-1-ruifeng.wang@arm.com>
The rte_smp_xx() APIs are deprecated. But it is not mentioned
in the function header.
Added notes in function header for clarification.
Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
v3: Added suggested memory ordering semantic for replacement.
Refined deprecation explanation.
v2: Made the notes more specific.
lib/eal/include/generic/rte_atomic.h | 30 ++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/lib/eal/include/generic/rte_atomic.h b/lib/eal/include/generic/rte_atomic.h
index 58df843c54..aef44e2455 100644
--- a/lib/eal/include/generic/rte_atomic.h
+++ b/lib/eal/include/generic/rte_atomic.h
@@ -55,6 +55,14 @@ static inline void rte_rmb(void);
* Guarantees that the LOAD and STORE operations that precede the
* rte_smp_mb() call are globally visible across the lcores
* before the LOAD and STORE operations that follows it.
+ *
+ * @note
+ * This function is deprecated.
+ * It provides similar synchronization primitive as atomic fence,
+ * but has different syntax and memory ordering semantic. Hence
+ * deprecated for the simplicity of memory ordering semantics in use.
+ *
+ * rte_atomic_thread_fence(__ATOMIC_ACQ_REL) should be used instead.
*/
static inline void rte_smp_mb(void);
@@ -64,6 +72,17 @@ static inline void rte_smp_mb(void);
* Guarantees that the STORE operations that precede the
* rte_smp_wmb() call are globally visible across the lcores
* before the STORE operations that follows it.
+ *
+ * @note
+ * This function is deprecated.
+ * It provides similar synchronization primitive as atomic fence,
+ * but has different syntax and memory ordering semantic. Hence
+ * deprecated for the simplicity of memory ordering semantics in use.
+ *
+ * rte_atomic_thread_fence(__ATOMIC_RELEASE) should be used instead.
+ * The fence also guarantees LOAD operations that precede the call
+ * are globally visible across the lcores before the STORE operations
+ * that follows it.
*/
static inline void rte_smp_wmb(void);
@@ -73,6 +92,17 @@ static inline void rte_smp_wmb(void);
* Guarantees that the LOAD operations that precede the
* rte_smp_rmb() call are globally visible across the lcores
* before the LOAD operations that follows it.
+ *
+ * @note
+ * This function is deprecated.
+ * It provides similar synchronization primitive as atomic fence,
+ * but has different syntax and memory ordering semantic. Hence
+ * deprecated for the simplicity of memory ordering semantics in use.
+ *
+ * rte_atomic_thread_fence(__ATOMIC_ACQUIRE) should be used instead.
+ * The fence also guarantees LOAD operations that precede the call
+ * are globally visible across the lcores before the STORE operations
+ * that follows it.
*/
static inline void rte_smp_rmb(void);
///@}
--
2.25.1
next prev parent reply other threads:[~2023-07-03 9:57 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-21 6:44 [PATCH] " Ruifeng Wang
2023-06-21 7:29 ` Thomas Monjalon
2023-06-25 7:55 ` Ruifeng Wang
2023-06-22 18:19 ` Mattias Rönnblom
2023-06-23 21:51 ` Tyler Retzlaff
2023-06-25 8:45 ` Ruifeng Wang
2023-06-25 15:40 ` Thomas Monjalon
2023-06-25 8:17 ` Ruifeng Wang
2023-06-29 19:28 ` Mattias Rönnblom
2023-07-03 6:12 ` Ruifeng Wang
2023-06-26 7:12 ` [PATCH v2] " Ruifeng Wang
2023-06-29 19:43 ` Mattias Rönnblom
2023-07-03 7:02 ` Ruifeng Wang
2023-07-04 12:08 ` Mattias Rönnblom
2023-07-03 9:56 ` Ruifeng Wang [this message]
2023-07-28 9:17 ` [PATCH v3] " Thomas Monjalon
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