Hi,
See comments below
On 08-Sep-2016 01:27:42 PM, Mohamad Gebai wrote:
> - 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
> result in nanoseconds. Note that the test automatically tries to reach
> a steady state before benchmarking.
>
> Signed-off-by: Mohamad Gebai <mohamad.ge...@gmail.com>
> ---
> instrumentation/events/lttng-module/lttng-test.h | 8 ++
> tests/probes/lttng-test.c | 118
> +++++++++++++++++++++--
> 2 files changed, 116 insertions(+), 10 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..dc59680 100644
> --- a/tests/probes/lttng-test.c
> +++ b/tests/probes/lttng-test.c
> @@ -23,6 +23,7 @@
> #include <linux/init.h>
> #include <linux/module.h>
> #include <linux/proc_fs.h>
> +#include <linux/timekeeping.h>
> #include <linux/byteorder/generic.h>
>
> #include <lttng-events.h>
> @@ -39,12 +40,18 @@
> #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"
Note that a patch to update all the tests that use this file in
lttng-tools will be needed if we change the path of
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 the results in nanoseconds. */
> +#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 +67,24 @@ void trace_test_event(unsigned int nr_iter)
> }
> }
>
> +static
> +void lttng_throughput_test(unsigned int nr_iter)
> +{
> + int i;
> + ktime_t start_time, end_time;
> +
> + /* Warm up and get to a steady state */
> + for(i = 0; i < nr_iter / 2; i++)
for (i =...
> + trace_lttng_test_throughput(i);
> +
> + start_time = ktime_get();
Do we really want to use ktime_get() directly and not the
trace_clock_read64 wrapper instead ? It might be easier to correlate the
aggregated result from latest_throughput_results with the generated
events list if they use the same clock.
> + for(i = 0; i < nr_iter; i++)
for (i =...
> + trace_lttng_test_throughput(i);
> + end_time = ktime_get();
> +
> + latest_throughput_results = ktime_to_ns(end_time) -
> ktime_to_ns(start_time);
> +}
> +
> /**
> * lttng_filter_event_write - trigger a lttng_test_filter_event
> * @file: file pointer
> @@ -90,10 +115,72 @@ 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;
add new line here
> +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)
if (latest_...
> + 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) {
> + 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;
goto error_event
> }
> + if(!proc_create_data(LTTNG_TEST_THROUGHPUT_FILE,
if (!proc...
> + 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;
goto error_event
> + }
> 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
Thanks,
Julien
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