int i;
bpage = ring_buffer_alloc_read_page(buffer);
+ if (!bpage)
+ return EVENT_DROPPED;
+
ret = ring_buffer_read_page(buffer, &bpage, PAGE_SIZE, cpu, 1);
if (ret >= 0) {
rpage = bpage;
event = (void *)&rpage->data[i];
switch (event->type_len) {
case RINGBUF_TYPE_PADDING:
- /* We don't expect any padding */
- KILL_TEST();
+ /* failed writes may be discarded events */
+ if (!event->time_delta)
+ KILL_TEST();
+ inc = event->array[0] + 4;
break;
case RINGBUF_TYPE_TIME_EXTEND:
inc = 8;
KILL_TEST();
break;
}
- inc = event->array[0];
+ inc = event->array[0] + 4;
break;
default:
entry = ring_buffer_event_data(event);
* Hammer the buffer for 10 secs (this may
* make the system stall)
*/
- pr_info("Starting ring buffer hammer\n");
+ trace_printk("Starting ring buffer hammer\n");
do_gettimeofday(&start_tv);
do {
struct ring_buffer_event *event;
}
do_gettimeofday(&end_tv);
- if (consumer && !(++cnt % wakeup_interval))
+ cnt++;
+ if (consumer && !(cnt % wakeup_interval))
wake_up_process(consumer);
+#ifndef CONFIG_PREEMPT
+ /*
+ * If we are a non preempt kernel, the 10 second run will
+ * stop everything while it runs. Instead, we will call
+ * cond_resched and also add any time that was lost by a
+ * rescedule.
+ *
+ * Do a cond resched at the same frequency we would wake up
+ * the reader.
+ */
+ if (cnt % wakeup_interval)
+ cond_resched();
+#endif
+
} while (end_tv.tv_sec < (start_tv.tv_sec + RUN_TIME) && !kill_test);
- pr_info("End ring buffer hammer\n");
+ trace_printk("End ring buffer hammer\n");
if (consumer) {
/* Init both completions here to avoid races */
}
time = end_tv.tv_sec - start_tv.tv_sec;
- time *= 1000000;
+ time *= USEC_PER_SEC;
time += (long long)((long)end_tv.tv_usec - (long)start_tv.tv_usec);
entries = ring_buffer_entries(buffer);
overruns = ring_buffer_overruns(buffer);
if (kill_test)
- pr_info("ERROR!\n");
- pr_info("Time: %lld (usecs)\n", time);
- pr_info("Overruns: %lld\n", overruns);
+ trace_printk("ERROR!\n");
+ trace_printk("Time: %lld (usecs)\n", time);
+ trace_printk("Overruns: %lld\n", overruns);
if (disable_reader)
- pr_info("Read: (reader disabled)\n");
+ trace_printk("Read: (reader disabled)\n");
else
- pr_info("Read: %ld (by %s)\n", read,
+ trace_printk("Read: %ld (by %s)\n", read,
read_events ? "events" : "pages");
- pr_info("Entries: %lld\n", entries);
- pr_info("Total: %lld\n", entries + overruns + read);
- pr_info("Missed: %ld\n", missed);
- pr_info("Hit: %ld\n", hit);
+ trace_printk("Entries: %lld\n", entries);
+ trace_printk("Total: %lld\n", entries + overruns + read);
+ trace_printk("Missed: %ld\n", missed);
+ trace_printk("Hit: %ld\n", hit);
- do_div(time, 1000);
+ /* Convert time from usecs to millisecs */
+ do_div(time, USEC_PER_MSEC);
if (time)
hit /= (long)time;
else
- pr_info("TIME IS ZERO??\n");
+ trace_printk("TIME IS ZERO??\n");
- pr_info("Entries per millisec: %ld\n", hit);
+ trace_printk("Entries per millisec: %ld\n", hit);
if (hit) {
- avg = 1000000 / hit;
- pr_info("%ld ns per entry\n", avg);
+ /* Calculate the average time in nanosecs */
+ avg = NSEC_PER_MSEC / hit;
+ trace_printk("%ld ns per entry\n", avg);
+ }
+
+ if (missed) {
+ if (time)
+ missed /= (long)time;
+
+ trace_printk("Total iterations per millisec: %ld\n",
+ hit + missed);
+
+ /* it is possible that hit + missed will overflow and be zero */
+ if (!(hit + missed)) {
+ trace_printk("hit + missed overflowed and totalled zero!\n");
+ hit--; /* make it non zero */
+ }
+
+ /* Caculate the average time in nanosecs */
+ avg = NSEC_PER_MSEC / (hit + missed);
+ trace_printk("%ld ns per entry\n", avg);
}
}
ring_buffer_producer();
- pr_info("Sleeping for 10 secs\n");
+ trace_printk("Sleeping for 10 secs\n");
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ * SLEEP_TIME);
__set_current_state(TASK_RUNNING);