Deal with kernel affinity bug for tests

[urcu.git] / test_qsbr.c

diff --git a/test_qsbr.c b/test_qsbr.c
index 6830fe1d2c1c77f144f1f28760bf2a2123cff2c4..af5ccfd58317d06d5c1e2d6c37ac0f268b0c5e16 100644 (file)
--- a/test_qsbr.c
+++ b/test_qsbr.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)
@@ -85,6 +88,26 @@ 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;
+
+static void set_affinity(void)
+{
+       cpu_set_t mask;
+       int cpu;
+
+       if (!use_affinity)
+               return;
+
+       cpu = cpu_affinities[next_aff++];
+       CPU_ZERO(&mask);
+       CPU_SET(cpu, &mask);
+       sched_setaffinity(0, sizeof(mask), &mask);
+}
+
+
+
 /*
  * returns 0 if test should end.
  */
@@ -171,6 +194,8 @@ 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)
@@ -212,6 +237,8 @@ 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)
        {
        }
@@ -256,8 +283,6 @@ void show_usage(int argc, char **argv)
        printf("\n");
 }
 
-cpu_set_t affinity;
-
 int main(int argc, char **argv)
 {
        int err;
@@ -266,7 +291,6 @@ 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);
@@ -291,8 +315,6 @@ int main(int argc, char **argv)
                return -1;
        }
 
-       CPU_ZERO(&affinity);
-
        for (i = 4; i < argc; i++) {
                if (argv[i][0] != '-')
                        continue;
@@ -311,7 +333,7 @@ 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;
@@ -342,34 +364,14 @@ 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) {
-               for (i = 0; i < CPU_SETSIZE; i++)
-                       if (CPU_ISSET(i, &affinity))
-                               printf_verbose("About to set affinity "
-                                              "to CPU : %d\n", i);
-
-               if (sched_setaffinity(0, sizeof(affinity), &affinity) < 0) {
-                       perror("sched_setaffinity");
-                       exit(-1);
-               }
-
-               if (sched_getaffinity(0, sizeof(affinity), &affinity) < 0) {
-                       perror("sched_getaffinity");
-                       exit(-1);
-               }
-
-               for (i = 0; i < CPU_SETSIZE; i++)
-                       if (CPU_ISSET(i, &affinity))
-                               printf_verbose("Effectively set affinity "
-                                              "to CPU : %d\n", i);
-       }
-
        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]);