Deal with kernel affinity bug for tests

[urcu.git] / test_urcu.c

diff --git a/test_urcu.c b/test_urcu.c
index fc9e8b539a9b3a9f21eb05702230602dd760b6d0..96dac983336bfa87a57fc861a6b780c843378fba 100644 (file)
--- a/test_urcu.c
+++ b/test_urcu.c
@@ -38,6 +38,9 @@
 /* Make this big enough to include the POWER5+ L3 cacheline size of 256B */
 #define CACHE_LINE_SIZE 4096
 
+/* hardcoded number of CPUs */
+#define NR_CPUS 16384
+
 #if defined(_syscall0)
 _syscall0(pid_t, gettid)
 #elif defined(__NR_gettid)
@@ -89,6 +92,37 @@ static int verbose_mode;
                        printf(fmt, args);      \
        } while (0)
 
+static unsigned int cpu_affinities[NR_CPUS];
+static unsigned int next_aff = 0;
+static int use_affinity = 0;
+
+pthread_mutex_t affinity_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void set_affinity(void)
+{
+       cpu_set_t mask;
+       int cpu;
+       int ret;
+
+       if (!use_affinity)
+               return;
+
+       ret = pthread_mutex_lock(&affinity_mutex);
+       if (ret) {
+               perror("Error in pthread mutex lock");
+               exit(-1);
+       }
+       cpu = cpu_affinities[next_aff++];
+       ret = pthread_mutex_unlock(&affinity_mutex);
+       if (ret) {
+               perror("Error in pthread mutex unlock");
+               exit(-1);
+       }
+       CPU_ZERO(&mask);
+       CPU_SET(cpu, &mask);
+       sched_setaffinity(0, sizeof(mask), &mask);
+}
+
 /*
  * returns 0 if test should end.
  */
@@ -175,6 +209,8 @@ void *thr_reader(void *_count)
        printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
                        "reader", pthread_self(), (unsigned long)gettid());
 
+       set_affinity();
+
        rcu_register_thread();
 
        while (!test_go)
@@ -213,6 +249,8 @@ void *thr_writer(void *_count)
        printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
                        "writer", pthread_self(), (unsigned long)gettid());
 
+       set_affinity();
+
        while (!test_go)
        {
        }
@@ -257,8 +295,6 @@ void show_usage(int argc, char **argv)
        printf("\n");
 }
 
-cpu_set_t affinity;
-
 int main(int argc, char **argv)
 {
        int err;
@@ -267,7 +303,6 @@ int main(int argc, char **argv)
        unsigned long long *count_reader, *count_writer;
        unsigned long long tot_reads = 0, tot_writes = 0;
        int i, a;
-       int use_affinity = 0;
 
        if (argc < 4) {
                show_usage(argc, argv);
@@ -292,8 +327,6 @@ int main(int argc, char **argv)
                return -1;
        }
 
-       CPU_ZERO(&affinity);
-
        for (i = 4; i < argc; i++) {
                if (argv[i][0] != '-')
                        continue;
@@ -312,7 +345,7 @@ int main(int argc, char **argv)
                                return -1;
                        }
                        a = atoi(argv[++i]);
-                       CPU_SET(a, &affinity);
+                       cpu_affinities[next_aff++] = a;
                        use_affinity = 1;
                        printf_verbose("Adding CPU %d affinity\n", a);
                        break;
@@ -343,18 +376,14 @@ int main(int argc, char **argv)
        printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
                        "main", pthread_self(), (unsigned long)gettid());
 
-       if (use_affinity
-           && sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
-               perror("sched_setaffinity");
-               exit(-1);
-       }
-
        test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
        tid_reader = malloc(sizeof(*tid_reader) * nr_readers);
        tid_writer = malloc(sizeof(*tid_writer) * nr_writers);
        count_reader = malloc(sizeof(*count_reader) * nr_readers);
        count_writer = malloc(sizeof(*count_writer) * nr_writers);
 
+       next_aff = 0;
+
        for (i = 0; i < nr_readers; i++) {
                err = pthread_create(&tid_reader[i], NULL, thr_reader,
                                     &count_reader[i]);