Debug level the mlx5_core driver

Infrastructure & Networking Adapters and Cables InfiniBand/VPI Adapter Cards
1

Dear all,

the documentation mentions to increase the verbosity of the driver by e.g.

echo 3 > /sys/modules/mlx5_core/parameters/debug_mask

But where does the output end up?

Cheers, Peter

2

Hi p.niessen,

Thank you for posting your inquiry to the NVIDIA Developer Forums!

To enable full debug output from the driver, you will need to use dynamic-debug:
https://www.kernel.org/doc/Documentation/dynamic-debug-howto.txt

1. Mount debugfs on the filesystem:

mount -t debugfs none /sys/kernel/debug

Review:

/sys/kernel/debug/dynamic_debug/control

Example:

// enable all the messages available in the mlx5_ib module
echo -n 'module mlx5_ib +p' > /sys/kernel/debug/dynamic_debug/control

// enable all messages
echo -n '+p' > /sys/kernel/debug/dynamic_debug/control​

These outputs will be captured in /dev/kmsg (dmesg).

To capture data related to function calls which are not provided by dynamic debug, you would need to use another method - ie, bpftrace.

Best,
NVIDIA Enterprise Experience