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authorSteven Rostedt <srostedt@redhat.com>2012-11-01 11:51:40 -0400
committerSteven Rostedt <rostedt@goodmis.org>2012-11-02 10:21:51 -0400
commit02404baf1b47123f1c88c9f9f1f3b00e1e2b10db (patch)
tree34b8379c9e36a2d89934cf867bb605d74967274d /kernel/trace
parent0fb9656d957d79dbe7ae155bb6533b1d465e4a50 (diff)
downloadlinux-02404baf1b47123f1c88c9f9f1f3b00e1e2b10db.tar.bz2
tracing: Remove deprecated tracing_enabled file
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 6752ab4a9c30d5411b2dfdb251a3f1cb18aae487 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: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/trace.c3
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3c9b96aee51a..d5cbc0d3f209 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4788,9 +4788,6 @@ static __init int tracer_init_debugfs(void)
d_tracer = tracing_init_dentry();
- trace_create_file("tracing_enabled", 0644, d_tracer,
- &global_trace, &rb_simple_fops);
-
trace_create_file("trace_options", 0644, d_tracer,
NULL, &tracing_iter_fops);