Provided by: systemtap-doc_2.3-1ubuntu1.4_all 

NAME
probe::vm.kfree - Fires when kfree is requested
SYNOPSIS
vm.kfree
VALUES
name
name of the probe point
call_site
address of the function calling this kmemory function
ptr
pointer to the kmemory allocated which is returned by kmalloc
caller_function
name of the caller function.
SystemTap Tapset Reference March 2016 PROBE::VM.KFREE(3stap)