See [INTspect][https://gitlab.cs.fau.de/i4/intspect].
## Sysfs Interface
Here's a minimal example that demonstrates how you can benchmark softirqs from
within a shell when INTsight has been injected into a kernel. INTspect
essentially does exactly this, except that it gathers some additional
information from `proc`.
``` shell
cd /sys/kernel/debug/intsight
echo> init
# Set the parameters
echo softirq > bottom_handler
echo 1000 > reps
# Execute the benchmark
echo> prepare_trigger
echo> do_trigger
echo> postprocess_trigger
# Optional: Inspect the results
head csv_results/pmccntr
cat reps # -> 1000
# Save the results and paramerters
cp-vrf. ~/my-insight
```
After this, `~/my-insight/csv_results` will contain the checkpoint names and
timestamps recorded.
## Sysfs Files
When injected into a kernel, INTsight provides a `debugfs` interface accessible
from user space, usually mounted in `/sys/kernel/debug/intsight`. INTspect uses
...
...
@@ -30,3 +59,13 @@ produced by INTspect.
| csv_results/name | Read-only CSV | One line per measurement run, each line contains the checkpoint names in the encountered order for this run |
| csv_results/* | Read-only CSVs | The recorded timestamps matching the checkpoint names in `csv_results/name` |
| vmalloc_checkpoint_matrix | Read-only Boolean | Determine whether the checkpoint buffer was small enough to be allocated using `kmalloc()`, or whether `vmalloc()` was required |
For each enabled timestamp, writing into `postprocess_trigger` creates a file in
the `csv_results` folder. Like `csv_results/name`, this files contains one line
per measurement run (the number of runs performed, was set before the benchmark
by writing into `reps`).
Each line in `csv_results/name` contains the checkpoint names in the encountered
order for this run (at most `checkpoint_capacity` fields), the respective
timestamps recorded during this checkpoint, can be found by opening the other
files in `csv_results`, and looking in the same row/column.
