Deal with kernel affinity bug for tests

[urcu.git] / test_qsbr.c

diff --git a/test_qsbr.c b/test_qsbr.c
index 82521efcf83a9babbf743f7741ad05a473efabb6..af5ccfd58317d06d5c1e2d6c37ac0f268b0c5e16 100644 (file)
--- a/test_qsbr.c
+++ b/test_qsbr.c
@@ -20,6 +20,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <pthread.h>
 #include <stdlib.h>
@@ -30,9 +31,16 @@
 #include <stdio.h>
 #include <assert.h>
 #include <sys/syscall.h>
+#include <sched.h>
 
 #include "arch.h"
 
+/* 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)
@@ -57,12 +65,49 @@ struct test_array {
 
 static volatile int test_go, test_stop;
 
-static int wdelay;
+static unsigned long wdelay;
 
 static struct test_array *test_rcu_pointer;
 
 static unsigned long duration;
 
+/* read-side C.S. duration, in loops */
+static unsigned long rduration;
+
+static inline void loop_sleep(unsigned long l)
+{
+       while(l-- != 0)
+               cpu_relax();
+}
+
+static int verbose_mode;
+
+#define printf_verbose(fmt, args...)           \
+       do {                                    \
+               if (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.
  */
@@ -146,9 +191,11 @@ void *thr_reader(void *_count)
        unsigned long long *count = _count;
        struct test_array *local_ptr;
 
-       printf("thread_begin %s, thread id : %lx, tid %lu\n",
+       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)
@@ -162,6 +209,8 @@ void *thr_reader(void *_count)
                debug_yield_read();
                if (local_ptr)
                        assert(local_ptr->a == 8);
+               if (unlikely(rduration))
+                       loop_sleep(rduration);
                _rcu_read_unlock();
                nr_reads++;
                /* QS each 1024 reads */
@@ -174,7 +223,7 @@ void *thr_reader(void *_count)
        rcu_unregister_thread();
 
        *count = nr_reads;
-       printf("thread_end %s, thread id : %lx, tid %lu\n",
+       printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
                        "reader", pthread_self(), (unsigned long)gettid());
        return ((void*)1);
 
@@ -185,9 +234,11 @@ void *thr_writer(void *_count)
        unsigned long long *count = _count;
        struct test_array *new, *old;
 
-       printf("thread_begin %s, thread id : %lx, tid %lu\n",
+       printf_verbose("thread_begin %s, thread id : %lx, tid %lu\n",
                        "writer", pthread_self(), (unsigned long)gettid());
 
+       set_affinity();
+
        while (!test_go)
        {
        }
@@ -210,10 +261,10 @@ void *thr_writer(void *_count)
                if (unlikely(!test_duration_write()))
                        break;
                if (unlikely(wdelay))
-                       usleep(wdelay);
+                       loop_sleep(wdelay);
        }
 
-       printf("thread_end %s, thread id : %lx, tid %lu\n",
+       printf_verbose("thread_end %s, thread id : %lx, tid %lu\n",
                        "writer", pthread_self(), (unsigned long)gettid());
        *count = nr_writes;
        return ((void*)2);
@@ -226,6 +277,9 @@ void show_usage(int argc, char **argv)
        printf(" [-r] [-w] (yield reader and/or writer)");
 #endif
        printf(" [-d delay] (writer period (us))");
+       printf(" [-c duration] (reader C.S. duration (in loops))");
+       printf(" [-v] (verbose output)");
+       printf(" [-a cpu#] [-a cpu#]... (affinity)");
        printf("\n");
 }
 
@@ -236,7 +290,7 @@ int main(int argc, char **argv)
        void *tret;
        unsigned long long *count_reader, *count_writer;
        unsigned long long tot_reads = 0, tot_writes = 0;
-       int i;
+       int i, a;
 
        if (argc < 4) {
                show_usage(argc, argv);
@@ -273,20 +327,41 @@ int main(int argc, char **argv)
                        yield_active |= YIELD_WRITE;
                        break;
 #endif
+               case 'a':
+                       if (argc < i + 2) {
+                               show_usage(argc, argv);
+                               return -1;
+                       }
+                       a = atoi(argv[++i]);
+                       cpu_affinities[next_aff++] = a;
+                       use_affinity = 1;
+                       printf_verbose("Adding CPU %d affinity\n", a);
+                       break;
+               case 'c':
+                       if (argc < i + 2) {
+                               show_usage(argc, argv);
+                               return -1;
+                       }
+                       rduration = atol(argv[++i]);
+                       break;
                case 'd':
                        if (argc < i + 2) {
                                show_usage(argc, argv);
                                return -1;
                        }
-                       wdelay = atoi(argv[++i]);
+                       wdelay = atol(argv[++i]);
+                       break;
+               case 'v':
+                       verbose_mode = 1;
                        break;
                }
        }
 
-       printf("running test for %lu seconds, %u readers, %u writers.\n",
+       printf_verbose("running test for %lu seconds, %u readers, %u writers.\n",
                duration, nr_readers, nr_writers);
-       printf("Writer delay : %u us.\n", wdelay);
-       printf("thread %-6s, thread id : %lx, tid %lu\n",
+       printf_verbose("Writer delay : %lu loops.\n", wdelay);
+       printf_verbose("Reader duration : %lu loops.\n", rduration);
+       printf_verbose("thread %-6s, thread id : %lx, tid %lu\n",
                        "main", pthread_self(), (unsigned long)gettid());
 
        test_array = malloc(sizeof(*test_array) * ARRAY_SIZE);
@@ -295,6 +370,8 @@ int main(int argc, char **argv)
        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]);
@@ -329,8 +406,14 @@ int main(int argc, char **argv)
                tot_writes += count_writer[i];
        }
        
-       printf("total number of reads : %llu, writes %llu\n", tot_reads,
+       printf_verbose("total number of reads : %llu, writes %llu\n", tot_reads,
               tot_writes);
+       printf("SUMMARY %-25s testdur %4lu nr_readers %3u rdur %6lu "
+               "nr_writers %3u "
+               "wdelay %6lu nr_reads %12llu nr_writes %12llu nr_ops %12llu\n",
+               argv[0], duration, nr_readers, rduration,
+               nr_writers, wdelay, tot_reads, tot_writes,
+               tot_reads + tot_writes);
        test_array_free(test_rcu_pointer);
        free(test_array);
        free(tid_reader);