• Steven Rostedt's avatar
    tracing: Remove deprecated tracing_enabled file · 02404baf
    Steven Rostedt authored
    The tracing_enabled file was used as a quick way to stop
    tracers, and try to bring down overhead for things like
    the latency tracers (irqsoff, wakeup, etc). But it didn't
    work that well.
    
    The tracing_on file was created as a really fast way to
    stop recording into the ftrace ring buffer and can interact
    with the kernel. That is a tracing_off() call in the kernel
    can disable recording of events, and then from userspace one
    could echo 1 into the tracing_on file to continue it. The
    tracing_enabled function did too much to allow for this.
    
    The tracing_on has taken over as a way to start and stop tracing
    and the tracing_enabled file should not be used. But because of
    its existance, it still confuses people. Over a year ago the
    following commit was added:
    
     commit 6752ab4a
     Author: Steven Rostedt <srostedt@redhat.com>
     Date:   Tue Feb 8 13:54:06 2011 -0500
    
        tracing: Deprecate tracing_enabled for tracing_on
    
    This commit added a WARN_ON() if the tracing_enabled file's variable
    was changed. After this was added, only LatencyTop complained, and
    they soon fixed their tool as there was no reason that LatencyTop
    should touch this file as it was using the perf ring buffers which
    this file does not interact with. But since that time no one else
    has complained about this WARN_ON(). Thus it is safe to assume that
    this file is no longer needed. Time to get rid of it.
    
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    02404baf
trace.c 117 KB