[dpdk-dev,2/2] Fix prefetch instruction on IBM POWER8

Message ID 1458893513-22406-3-git-send-email-chaozhu@linux.vnet.ibm.com (mailing list archive)
State Changes Requested, archived
Delegated to: Thomas Monjalon
Headers

Commit Message

Chao Zhu March 25, 2016, 8:11 a.m. UTC
  Current prefetch instruction (dcbt) implementation for IBM POWER8 has wrong
Touch Hint(TH) parameter. The current setting of TH=1 indicates to load data from
current cache line and an unlimited number of sequentially following cache lines.
TTH=0 means to load data from current cache line. rte_prefetch0 function is defined
to load one cache line, which means TH=0 is suited here.

Signed-off-by: Chao Zhu <chaozhu@linux.vnet.ibm.com>
---
 .../common/include/arch/ppc_64/rte_prefetch.h      |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
  

Patch

diff --git a/lib/librte_eal/common/include/arch/ppc_64/rte_prefetch.h b/lib/librte_eal/common/include/arch/ppc_64/rte_prefetch.h
index bcc7185..9a1995e 100644
--- a/lib/librte_eal/common/include/arch/ppc_64/rte_prefetch.h
+++ b/lib/librte_eal/common/include/arch/ppc_64/rte_prefetch.h
@@ -41,17 +41,17 @@  extern "C" {
 
 static inline void rte_prefetch0(const volatile void *p)
 {
-	asm volatile ("dcbt 0,%[p],1" : : [p] "r" (p));
+	asm volatile ("dcbt 0,%[p],0" : : [p] "r" (p));
 }
 
 static inline void rte_prefetch1(const volatile void *p)
 {
-	asm volatile ("dcbt 0,%[p],1" : : [p] "r" (p));
+	asm volatile ("dcbt 0,%[p],0" : : [p] "r" (p));
 }
 
 static inline void rte_prefetch2(const volatile void *p)
 {
-	asm volatile ("dcbt 0,%[p],1" : : [p] "r" (p));
+	asm volatile ("dcbt 0,%[p],0" : : [p] "r" (p));
 }
 
 static inline void rte_prefetch_non_temporal(const volatile void *p)