From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Sat, 13 Jun 2009 23:10:31 +0000 (-0400)
Subject: Deal with POWER5+ 256B L3 cachefalse sharing for per thread lock
X-Git-Tag: v0.1~148
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=55271c137f2480d80f675a8935d28ad22516438e;p=urcu.git

Deal with POWER5+ 256B L3 cachefalse sharing for per thread lock

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---

diff --git a/test_mutex.c b/test_mutex.c
index d481810..8b48040 100644
--- a/test_mutex.c
+++ b/test_mutex.c
@@ -35,6 +35,9 @@
 
 #include "arch.h"
 
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)
@@ -104,8 +107,10 @@ static int test_duration_read(void)
 static unsigned long long __thread nr_writes;
 static unsigned long long __thread nr_reads;
 
-static unsigned long long __attribute__((aligned(128))) *tot_nr_writes;
-static unsigned long long __attribute__((aligned(128))) *tot_nr_reads;
+static
+unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
+static
+unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_reads;
 
 static unsigned int nr_readers;
 static unsigned int nr_writers;
diff --git a/test_perthreadlock.c b/test_perthreadlock.c
index 89cce65..3fc4a53 100644
--- a/test_perthreadlock.c
+++ b/test_perthreadlock.c
@@ -35,6 +35,9 @@
 
 #include "arch.h"
 
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)
@@ -63,7 +66,7 @@ struct test_array {
 
 struct per_thread_lock {
 	pthread_mutex_t lock;
-} __attribute__((aligned(128)));	/* cache-line aligned */
+} __attribute__((aligned(CACHE_LINE_SIZE)));	/* cache-line aligned */
 
 static struct per_thread_lock *per_thread_lock;
 
@@ -108,8 +111,10 @@ static int test_duration_read(void)
 static unsigned long long __thread nr_writes;
 static unsigned long long __thread nr_reads;
 
-static unsigned long long __attribute__((aligned(128))) *tot_nr_writes;
-static unsigned long long __attribute__((aligned(128))) *tot_nr_reads;
+static
+unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_writes;
+static
+unsigned long long __attribute__((aligned(CACHE_LINE_SIZE))) *tot_nr_reads;
 
 static unsigned int nr_readers;
 static unsigned int nr_writers;
diff --git a/test_qsbr.c b/test_qsbr.c
index dc871dc..2e1a0ec 100644
--- a/test_qsbr.c
+++ b/test_qsbr.c
@@ -35,6 +35,9 @@
 
 #include "arch.h"
 
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)
diff --git a/test_rwlock.c b/test_rwlock.c
index 915027d..733263b 100644
--- a/test_rwlock.c
+++ b/test_rwlock.c
@@ -35,6 +35,9 @@
 
 #include "arch.h"
 
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)
diff --git a/test_urcu.c b/test_urcu.c
index 696c09e..fc9e8b5 100644
--- a/test_urcu.c
+++ b/test_urcu.c
@@ -35,6 +35,9 @@
 
 #include "arch.h"
 
+/* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
+#define CACHE_LINE_SIZE 4096
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)