[lttng-dev] [PATCH LTTng-modules v2] Add throughput test to LTTng
Mohamad Gebai
mohamad.gebai at gmail.com
Tue Sep 13 11:26:50 UTC 2016
- Create the lttng-test subdirectory under /proc for testing purposes.
- Create the procfs throughput file. Start a throughput test by writing
the number of iterations for the test. Read from this file to get the
total duration. Note that the test automatically tries to reach a steady
state before benchmarking.
Signed-off-by: Mohamad Gebai <mohamad.gebai at gmail.com>
---
instrumentation/events/lttng-module/lttng-test.h | 8 ++
tests/probes/lttng-test.c | 120 ++++++++++++++++++++---
2 files changed, 117 insertions(+), 11 deletions(-)
diff --git a/instrumentation/events/lttng-module/lttng-test.h b/instrumentation/events/lttng-module/lttng-test.h
index 05d028c..54b4404 100644
--- a/instrumentation/events/lttng-module/lttng-test.h
+++ b/instrumentation/events/lttng-module/lttng-test.h
@@ -48,6 +48,14 @@ LTTNG_TRACEPOINT_EVENT(lttng_test_filter_event,
)
)
+LTTNG_TRACEPOINT_EVENT(lttng_test_throughput,
+ TP_PROTO(int anint),
+ TP_ARGS(anint),
+ TP_FIELDS(
+ ctf_integer(int, intfield, anint)
+ )
+)
+
#endif /* LTTNG_TRACE_LTTNG_TEST_H */
/* This part must be outside protection */
diff --git a/tests/probes/lttng-test.c b/tests/probes/lttng-test.c
index 54be4c7..b42ea1c 100644
--- a/tests/probes/lttng-test.c
+++ b/tests/probes/lttng-test.c
@@ -39,12 +39,18 @@
#include <instrumentation/events/lttng-module/lttng-test.h>
DEFINE_TRACE(lttng_test_filter_event);
+DEFINE_TRACE(lttng_test_throughput);
-#define LTTNG_TEST_FILTER_EVENT_FILE "lttng-test-filter-event"
+#define LTTNG_TEST_PROCFS_DIR "lttng-test"
+#define LTTNG_TEST_FILTER_EVENT_FILE "filter-event"
+/* Do a throughput benchmark by writing to this file the number of events.
+ * Read to get the duration of the benchmark. */
+#define LTTNG_TEST_THROUGHPUT_FILE "throughput"
#define LTTNG_WRITE_COUNT_MAX 64
-static struct proc_dir_entry *lttng_test_filter_event_dentry;
+static struct proc_dir_entry *lttng_test_dentry;
+static u64 latest_throughput_results = 0;
static
void trace_test_event(unsigned int nr_iter)
@@ -60,6 +66,24 @@ void trace_test_event(unsigned int nr_iter)
}
}
+static
+void lttng_throughput_test(unsigned int nr_iter)
+{
+ int i;
+ u64 start_time, end_time;
+
+ /* Warm up and get to a steady state */
+ for (i = 0; i < nr_iter / 2; i++)
+ trace_lttng_test_throughput(i);
+
+ start_time = trace_clock_read64();
+ for (i = 0; i < nr_iter; i++)
+ trace_lttng_test_throughput(i);
+ end_time = trace_clock_read64();
+
+ latest_throughput_results = end_time - start_time;
+}
+
/**
* lttng_filter_event_write - trigger a lttng_test_filter_event
* @file: file pointer
@@ -90,10 +114,73 @@ end:
return written;
}
+/**
+ * lttng_throughput_test_write - trigger a lttng_throughput_test
+ * @file: file pointer
+ * @user_buf: user string
+ * @count: length to copy
+ *
+ * Return -1 on error, with EFAULT errno. Returns count on success.
+ */
+static
+ssize_t lttng_throughput_test_write(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned int nr_iter;
+ ssize_t written;
+ int ret;
+
+ /* Get the number of iterations */
+ ret = lttng_kstrtouint_from_user(user_buf, count, 10, &nr_iter);
+ if (ret) {
+ written = ret;
+ goto end;
+ }
+ /* Do throughput test */
+ lttng_throughput_test(nr_iter);
+ written = count;
+ *ppos += written;
+
+end:
+ return written;
+}
+
+/**
+ * lttng_throughput_test_read - read latest results of throughput test
+ * @file: file pointer
+ * @user_buf: user string
+ * @count: length to copy
+ *
+ * Return -1 on error, with EFAULT errno. Returns count on success.
+ */
+static
+ssize_t lttng_throughput_test_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[count];
+ ssize_t read_count = 0;
+
+ if (latest_throughput_results == 0)
+ goto end;
+
+ read_count += snprintf(buf, count, "%llu\n", latest_throughput_results);
+ copy_to_user(user_buf, buf, count);
+ latest_throughput_results = 0;
+
+end:
+ return read_count;
+}
+
static const struct file_operations lttng_test_filter_event_operations = {
.write = lttng_test_filter_event_write,
};
+static const struct file_operations lttng_throughput_test_operations = {
+ .write = lttng_throughput_test_write,
+ .read = lttng_throughput_test_read,
+};
+
static
int __init lttng_test_init(void)
{
@@ -101,22 +188,33 @@ int __init lttng_test_init(void)
(void) wrapper_lttng_fixup_sig(THIS_MODULE);
wrapper_vmalloc_sync_all();
- lttng_test_filter_event_dentry =
- proc_create_data(LTTNG_TEST_FILTER_EVENT_FILE,
- S_IRUGO | S_IWUGO, NULL,
- <tng_test_filter_event_operations, NULL);
- if (!lttng_test_filter_event_dentry) {
- printk(KERN_ERR "Error creating LTTng test filter file\n");
+ lttng_test_dentry = proc_mkdir(LTTNG_TEST_PROCFS_DIR, NULL);
+ if (!lttng_test_dentry) {
+ printk(KERN_ERR "Error creating LTTng test directory\n");
ret = -ENOMEM;
goto error;
}
+ if (!proc_create_data(LTTNG_TEST_FILTER_EVENT_FILE,
+ S_IRUGO | S_IWUGO, lttng_test_dentry,
+ <tng_test_filter_event_operations, NULL)) {
+ printk(KERN_ERR "Error creating LTTng test filter file\n");
+ ret = -ENOMEM;
+ goto error_events;
+ }
+ if (!proc_create_data(LTTNG_TEST_THROUGHPUT_FILE,
+ S_IRUGO | S_IWUGO, lttng_test_dentry,
+ <tng_throughput_test_operations, NULL)) {
+ printk(KERN_ERR "Error creating LTTng test throughput file\n");
+ ret = -ENOMEM;
+ goto error_events;
+ }
ret = __lttng_events_init__lttng_test();
if (ret)
goto error_events;
return ret;
error_events:
- remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
+ remove_proc_subtree(LTTNG_TEST_PROCFS_DIR, NULL);
error:
return ret;
}
@@ -127,8 +225,8 @@ static
void __exit lttng_test_exit(void)
{
__lttng_events_exit__lttng_test();
- if (lttng_test_filter_event_dentry)
- remove_proc_entry(LTTNG_TEST_FILTER_EVENT_FILE, NULL);
+ if (lttng_test_dentry)
+ remove_proc_subtree(LTTNG_TEST_PROCFS_DIR, NULL);
}
module_exit(lttng_test_exit);
--
2.5.0
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