• Tom Zanussi's avatar
    tracing: Add 'enable_event' and 'disable_event' event trigger commands · 7862ad18
    Tom Zanussi authored
    Add 'enable_event' and 'disable_event' event_command commands.
    
    enable_event and disable_event event triggers are added by the user
    via these commands in a similar way and using practically the same
    syntax as the analagous 'enable_event' and 'disable_event' ftrace
    function commands, but instead of writing to the set_ftrace_filter
    file, the enable_event and disable_event triggers are written to the
    per-event 'trigger' files:
    
        echo 'enable_event:system:event' > .../othersys/otherevent/trigger
        echo 'disable_event:system:event' > .../othersys/otherevent/trigger
    
    The above commands will enable or disable the 'system:event' trace
    events whenever the othersys:otherevent events are hit.
    
    This also adds a 'count' version that limits the number of times the
    command will be invoked:
    
        echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger
        echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger
    
    Where N is the number of times the command will be invoked.
    
    The above commands will will enable or disable the 'system:event'
    trace events whenever the othersys:otherevent events are hit, but only
    N times.
    
    This also makes the find_event_file() helper function extern, since
    it's useful to use from other places, such as the event triggers code,
    so make it accessible.
    
    Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.com
    
    Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    7862ad18
trace.h 38.1 KB