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* [dpdk-dev] [PATCH] eal/ppc: remove fix of memory barrier for IBM POWER
@ 2019-03-18 12:58 Dekel Peled
  2019-03-18 12:58 ` Dekel Peled
                   ` (2 more replies)
  0 siblings, 3 replies; 42+ messages in thread
From: Dekel Peled @ 2019-03-18 12:58 UTC (permalink / raw)
  To: chaozhu; +Cc: yskoh, shahafs, dev, orika, thomas, dekelp, stable

>From previous patch description: "to improve performance on PPC64,
use light weight sync instruction instead of sync instruction."

Excerpt from IBM doc [1], section "Memory barrier instructions":
"The second form of the sync instruction is light-weight sync,
or lwsync.
This form is used to control ordering for storage accesses to system
memory only. It does not create a memory barrier for accesses to
device memory."

This patch removes the use of lwsync, so calls to rte_wmb() and
rte_rmb() will provide correct memory barrier to ensure order of
accesses to system memory and device memory.

[1] https://www.ibm.com/developerworks/systems/articles/powerpc.html

Fixes: d23a6bd04d72 ("eal/ppc: fix memory barrier for IBM POWER")
Cc: stable@dpdk.org

Signed-off-by: Dekel Peled <dekelp@mellanox.com>
---
 lib/librte_eal/common/include/arch/ppc_64/rte_atomic.h | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_atomic.h b/lib/librte_eal/common/include/arch/ppc_64/rte_atomic.h
index ce38350..797381c 100644
--- a/lib/librte_eal/common/include/arch/ppc_64/rte_atomic.h
+++ b/lib/librte_eal/common/include/arch/ppc_64/rte_atomic.h
@@ -63,11 +63,7 @@
  * Guarantees that the STORE operations generated before the barrier
  * occur before the STORE operations generated after.
  */
-#ifdef RTE_ARCH_64
-#define	rte_wmb() asm volatile("lwsync" : : : "memory")
-#else
 #define	rte_wmb() asm volatile("sync" : : : "memory")
-#endif
 
 /**
  * Read memory barrier.
@@ -75,11 +71,7 @@
  * Guarantees that the LOAD operations generated before the barrier
  * occur before the LOAD operations generated after.
  */
-#ifdef RTE_ARCH_64
-#define	rte_rmb() asm volatile("lwsync" : : : "memory")
-#else
 #define	rte_rmb() asm volatile("sync" : : : "memory")
-#endif
 
 #define rte_smp_mb() rte_mb()
 
-- 
1.8.3.1

^ permalink raw reply	[flat|nested] 42+ messages in thread

end of thread, other threads:[~2019-03-28 22:50 UTC | newest]

Thread overview: 42+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-18 12:58 [dpdk-dev] [PATCH] eal/ppc: remove fix of memory barrier for IBM POWER Dekel Peled
2019-03-18 12:58 ` Dekel Peled
2019-03-19  3:24 ` Chao Zhu
2019-03-19  3:24   ` Chao Zhu
2019-03-19 10:05   ` Dekel Peled
2019-03-19 10:05     ` Dekel Peled
2019-03-19 11:14     ` Thomas Monjalon
2019-03-19 11:14       ` Thomas Monjalon
2019-03-19 19:42       ` Shahaf Shuler
2019-03-19 19:42         ` Shahaf Shuler
2019-03-19 20:45         ` Thomas Monjalon
2019-03-19 20:45           ` Thomas Monjalon
2019-03-20 22:40           ` Pradeep Satyanarayana
2019-03-20 22:40             ` Pradeep Satyanarayana
2019-03-21  8:49             ` Shahaf Shuler
2019-03-21  8:49               ` Shahaf Shuler
2019-03-22  1:40               ` Pradeep Satyanarayana
2019-03-22  1:40                 ` Pradeep Satyanarayana
2019-03-22  8:49                 ` Thomas Monjalon
2019-03-22  8:49                   ` Thomas Monjalon
2019-03-22 15:30                   ` Pradeep Satyanarayana
2019-03-22 15:30                     ` Pradeep Satyanarayana
2019-03-22 17:51                     ` Thomas Monjalon
2019-03-22 17:51                       ` Thomas Monjalon
2019-03-22 22:57                       ` Pradeep Satyanarayana
2019-03-22 22:57                         ` Pradeep Satyanarayana
2019-03-24  6:37                         ` Shahaf Shuler
2019-03-24  6:37                           ` Shahaf Shuler
2019-03-24 17:37                           ` Pradeep Satyanarayana
2019-03-24 17:37                             ` Pradeep Satyanarayana
2019-03-26  9:15                             ` Dekel Peled
2019-03-26  9:15                               ` Dekel Peled
2019-03-27  9:19                               ` Thomas Monjalon
2019-03-27  9:19                                 ` Thomas Monjalon
2019-03-27 23:50                                 ` Pradeep Satyanarayana
2019-03-27 23:50                                   ` Pradeep Satyanarayana
     [not found]                                 ` <OF456B0ECC.006EF7E7-ON882583CA.00827A75-882583CA.0082F7BE@LocalDomain>
2019-03-28 17:51                                   ` Pradeep Satyanarayana
2019-03-28 17:51                                     ` Pradeep Satyanarayana
2019-03-28 17:56                                     ` Thomas Monjalon
2019-03-28 17:56                                       ` Thomas Monjalon
2019-03-28 22:50 ` [dpdk-dev] [dpdk-stable] " Thomas Monjalon
2019-03-28 22:50   ` Thomas Monjalon

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