• Steven Rostedt's avatar
    ftrace: add kernel command line function filtering · 2af15d6a
    Steven Rostedt authored
    When using ftrace=function on the command line to trace functions
    on boot up, one can not filter out functions that are commonly called.
    
    This patch adds two new ftrace command line commands.
    
      ftrace_notrace=function-list
      ftrace_filter=function-list
    
    Where function-list is a comma separated list of functions to filter.
    The ftrace_notrace will make the functions listed not be included
    in the function tracing, and ftrace_filter will only trace the functions
    listed.
    
    These two act the same as the debugfs/tracing/set_ftrace_notrace and
    debugfs/tracing/set_ftrace_filter respectively.
    
    The simple glob expressions that are allowed by the filter files can also
    be used by the command line interface.
    
    	ftrace_notrace=rcu*,*lock,*spin*
    
    Will not trace any function that starts with rcu, ends with lock, or has
    the word spin in it.
    
    Note, if the self tests are enabled, they may interfere with the filtering
    set by the command lines.
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    2af15d6a
ftrace.c 69.7 KB