How to enable debugfs on linux system.

Debugfs is Debug Filesystem , its RAM based filesystem which can be used for kernel debugging information. This makes kernel space information available in user space.

How to enable debugfs :

To enable it for onetime, i.e information will be available until next boot of system.

mount -t debugfs none /sys/kernel/debug

To make the change permanent, add following line to /etc/fstab file.

debugfs    /sys/kernel/debug      debugfs  defaults  0 0

Once you enable debugfs, you can see multiple directories inside /sys/kernel/debug :

[root@sandbox ~]# ls /sys/kernel/debug
bdi    boot_params  dynamic_debug  gpio  kprobes  sched_features  usb  xen
block  dma_buf      extfrag        hid   mce      tracing         x86

These files holds information about kernel subsystems which helps in debugging.