These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / kernel / trace / ring_buffer_benchmark.c

diff --git a/kernel/kernel/trace/ring_buffer_benchmark.c b/kernel/kernel/trace/ring_buffer_benchmark.c
index 1b28df2..6df9a83 100644 (file)
--- a/kernel/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/kernel/trace/ring_buffer_benchmark.c
@@ -24,19 +24,19 @@ struct rb_page {
 static int wakeup_interval = 100;
 
 static int reader_finish;
-static struct completion read_start;
-static struct completion read_done;
+static DECLARE_COMPLETION(read_start);
+static DECLARE_COMPLETION(read_done);
 
 static struct ring_buffer *buffer;
 static struct task_struct *producer;
 static struct task_struct *consumer;
 static unsigned long read;
 
-static int disable_reader;
+static unsigned int disable_reader;
 module_param(disable_reader, uint, 0644);
 MODULE_PARM_DESC(disable_reader, "only run producer");
 
-static int write_iteration = 50;
+static unsigned int write_iteration = 50;
 module_param(write_iteration, uint, 0644);
 MODULE_PARM_DESC(write_iteration, "# of writes between timestamp readings");
 
@@ -46,26 +46,26 @@ static int consumer_nice = MAX_NICE;
 static int producer_fifo = -1;
 static int consumer_fifo = -1;
 
-module_param(producer_nice, uint, 0644);
+module_param(producer_nice, int, 0644);
 MODULE_PARM_DESC(producer_nice, "nice prio for producer");
 
-module_param(consumer_nice, uint, 0644);
+module_param(consumer_nice, int, 0644);
 MODULE_PARM_DESC(consumer_nice, "nice prio for consumer");
 
-module_param(producer_fifo, uint, 0644);
+module_param(producer_fifo, int, 0644);
 MODULE_PARM_DESC(producer_fifo, "fifo prio for producer");
 
-module_param(consumer_fifo, uint, 0644);
+module_param(consumer_fifo, int, 0644);
 MODULE_PARM_DESC(consumer_fifo, "fifo prio for consumer");
 
 static int read_events;
 
-static int kill_test;
+static int test_error;
 
-#define KILL_TEST()                            \
+#define TEST_ERROR()                           \
        do {                                    \
-               if (!kill_test) {               \
-                       kill_test = 1;          \
+               if (!test_error) {              \
+                       test_error = 1;         \
                        WARN_ON(1);             \
                }                               \
        } while (0)
@@ -75,6 +75,11 @@ enum event_status {
        EVENT_DROPPED,
 };
 
+static bool break_test(void)
+{
+       return test_error || kthread_should_stop();
+}
+
 static enum event_status read_event(int cpu)
 {
        struct ring_buffer_event *event;
@@ -87,7 +92,7 @@ static enum event_status read_event(int cpu)
 
        entry = ring_buffer_event_data(event);
        if (*entry != cpu) {
-               KILL_TEST();
+               TEST_ERROR();
                return EVENT_DROPPED;
        }
 
@@ -115,10 +120,10 @@ static enum event_status read_page(int cpu)
                rpage = bpage;
                /* The commit may have missed event flags set, clear them */
                commit = local_read(&rpage->commit) & 0xfffff;
-               for (i = 0; i < commit && !kill_test; i += inc) {
+               for (i = 0; i < commit && !test_error ; i += inc) {
 
                        if (i >= (PAGE_SIZE - offsetof(struct rb_page, data))) {
-                               KILL_TEST();
+                               TEST_ERROR();
                                break;
                        }
 
@@ -128,7 +133,7 @@ static enum event_status read_page(int cpu)
                        case RINGBUF_TYPE_PADDING:
                                /* failed writes may be discarded events */
                                if (!event->time_delta)
-                                       KILL_TEST();
+                                       TEST_ERROR();
                                inc = event->array[0] + 4;
                                break;
                        case RINGBUF_TYPE_TIME_EXTEND:
@@ -137,12 +142,12 @@ static enum event_status read_page(int cpu)
                        case 0:
                                entry = ring_buffer_event_data(event);
                                if (*entry != cpu) {
-                                       KILL_TEST();
+                                       TEST_ERROR();
                                        break;
                                }
                                read++;
                                if (!event->array[0]) {
-                                       KILL_TEST();
+                                       TEST_ERROR();
                                        break;
                                }
                                inc = event->array[0] + 4;
@@ -150,17 +155,17 @@ static enum event_status read_page(int cpu)
                        default:
                                entry = ring_buffer_event_data(event);
                                if (*entry != cpu) {
-                                       KILL_TEST();
+                                       TEST_ERROR();
                                        break;
                                }
                                read++;
                                inc = ((event->type_len + 1) * 4);
                        }
-                       if (kill_test)
+                       if (test_error)
                                break;
 
                        if (inc <= 0) {
-                               KILL_TEST();
+                               TEST_ERROR();
                                break;
                        }
                }
@@ -178,10 +183,14 @@ static void ring_buffer_consumer(void)
        read_events ^= 1;
 
        read = 0;
-       while (!reader_finish && !kill_test) {
-               int found;
+       /*
+        * Continue running until the producer specifically asks to stop
+        * and is ready for the completion.
+        */
+       while (!READ_ONCE(reader_finish)) {
+               int found = 1;
 
-               do {
+               while (found && !test_error) {
                        int cpu;
 
                        found = 0;
@@ -193,19 +202,25 @@ static void ring_buffer_consumer(void)
                                else
                                        stat = read_page(cpu);
 
-                               if (kill_test)
+                               if (test_error)
                                        break;
+
                                if (stat == EVENT_FOUND)
                                        found = 1;
+
                        }
-               } while (found && !kill_test);
+               }
 
+               /* Wait till the producer wakes us up when there is more data
+                * available or when the producer wants us to finish reading.
+                */
                set_current_state(TASK_INTERRUPTIBLE);
                if (reader_finish)
                        break;
 
                schedule();
        }
+       __set_current_state(TASK_RUNNING);
        reader_finish = 0;
        complete(&read_done);
 }
@@ -263,8 +278,7 @@ static void ring_buffer_producer(void)
                if (cnt % wakeup_interval)
                        cond_resched();
 #endif
-
-       } while (ktime_before(end_time, timeout) && !kill_test);
+       } while (ktime_before(end_time, timeout) && !break_test());
        trace_printk("End ring buffer hammer\n");
 
        if (consumer) {
@@ -274,8 +288,6 @@ static void ring_buffer_producer(void)
                /* the completions must be visible before the finish var */
                smp_wmb();
                reader_finish = 1;
-               /* finish var visible before waking up the consumer */
-               smp_wmb();
                wake_up_process(consumer);
                wait_for_completion(&read_done);
        }
@@ -285,7 +297,7 @@ static void ring_buffer_producer(void)
        entries = ring_buffer_entries(buffer);
        overruns = ring_buffer_overruns(buffer);
 
-       if (kill_test)
+       if (test_error)
                trace_printk("ERROR!\n");
 
        if (!disable_reader) {
@@ -366,20 +378,19 @@ static void wait_to_die(void)
 
 static int ring_buffer_consumer_thread(void *arg)
 {
-       while (!kthread_should_stop() && !kill_test) {
+       while (!break_test()) {
                complete(&read_start);
 
                ring_buffer_consumer();
 
                set_current_state(TASK_INTERRUPTIBLE);
-               if (kthread_should_stop() || kill_test)
+               if (break_test())
                        break;
-
                schedule();
        }
        __set_current_state(TASK_RUNNING);
 
-       if (kill_test)
+       if (!kthread_should_stop())
                wait_to_die();
 
        return 0;
@@ -387,25 +398,28 @@ static int ring_buffer_consumer_thread(void *arg)
 
 static int ring_buffer_producer_thread(void *arg)
 {
-       init_completion(&read_start);
-
-       while (!kthread_should_stop() && !kill_test) {
+       while (!break_test()) {
                ring_buffer_reset(buffer);
 
                if (consumer) {
-                       smp_wmb();
                        wake_up_process(consumer);
                        wait_for_completion(&read_start);
                }
 
                ring_buffer_producer();
+               if (break_test())
+                       goto out_kill;
 
                trace_printk("Sleeping for 10 secs\n");
                set_current_state(TASK_INTERRUPTIBLE);
+               if (break_test())
+                       goto out_kill;
                schedule_timeout(HZ * SLEEP_TIME);
        }
 
-       if (kill_test)
+out_kill:
+       __set_current_state(TASK_RUNNING);
+       if (!kthread_should_stop())
                wait_to_die();
 
        return 0;