From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 20/22] tracing: Remove deprecated tracing_enabled file
Date: Fri, 02 Nov 2012 09:33:12 -0400 [thread overview]
Message-ID: <20121102133501.643958787@goodmis.org> (raw)
In-Reply-To: 20121102133251.998500247@goodmis.org
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From: Steven Rostedt <srostedt@redhat.com>
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>
---
kernel/trace/trace.c | 3 ---
1 file changed, 3 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 4b83a03..8eaa837 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4809,9 +4809,6 @@ 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);
--
1.7.10.4
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next prev parent reply other threads:[~2012-11-02 13:36 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-02 13:32 [PATCH 00/22] [GIT PULL][3.8] tracing: updates Steven Rostedt
2012-11-02 13:32 ` [PATCH 01/22] tracing: Replace strict_strto* with kstrto* Steven Rostedt
2012-11-02 13:32 ` [PATCH 02/22] tracing: Allow tracers to start at core initcall Steven Rostedt
2012-11-02 13:32 ` [PATCH 03/22] tracing: Change tracers integer flags to bool Steven Rostedt
2012-11-02 13:32 ` [PATCH 04/22] ring-buffer: Add a dropped events counter Steven Rostedt
2012-11-02 13:32 ` [PATCH 05/22] tracing: Expand ring buffer when trace_printk() is used Steven Rostedt
2012-11-02 13:32 ` [PATCH 06/22] tracing: Enable comm recording if " Steven Rostedt
2012-11-02 13:32 ` [PATCH 07/22] tracing: Have tracing_sched_wakeup_trace() use standard unlock_commit Steven Rostedt
2012-11-02 13:33 ` [PATCH 08/22] tracing: Cache comms only after an event occurred Steven Rostedt
2012-11-02 13:33 ` [PATCH 09/22] tracing: Trivial cleanup Steven Rostedt
2012-11-02 13:33 ` [PATCH 10/22] tracing: Cleanup unnecessary function declarations Steven Rostedt
2012-11-02 13:33 ` [PATCH 11/22] linux/kernel.h: Remove duplicate trace_printk declaration Steven Rostedt
2012-11-02 13:33 ` [PATCH 12/22] tracing,x86: Add a TSC trace_clock Steven Rostedt
2012-11-02 13:33 ` [PATCH 13/22] tracing: Reset ring buffer when changing trace_clocks Steven Rostedt
2012-11-02 13:33 ` [PATCH 14/22] tracing: Format non-nanosec times from tsc clock without a decimal point Steven Rostedt
2012-11-02 13:33 ` [PATCH 15/22] ring-buffer: Change unsigned long type of ring_buffer_oldest_event_ts() to u64 Steven Rostedt
2012-11-02 13:33 ` [PATCH 16/22] tracing: Show raw time stamp on stats per cpu using counter or tsc mode for trace_clock Steven Rostedt
2012-11-02 13:33 ` [PATCH 17/22] tracing: Separate open function from set_event and available_events Steven Rostedt
2012-11-02 13:33 ` [PATCH 18/22] tracing: Remove unused function unregister_tracer() Steven Rostedt
2012-11-02 13:33 ` [PATCH 19/22] tracing: Make tracing_enabled be equal to tracing_on Steven Rostedt
2012-11-02 13:33 ` Steven Rostedt [this message]
2012-11-02 13:33 ` [PATCH 21/22] tracing: Use irq_work for wake ups and remove *_nowake_*() functions Steven Rostedt
2012-11-02 13:33 ` [PATCH 22/22] tracing: Add trace_options kernel command line parameter Steven Rostedt
2012-11-02 14:08 ` [PATCH 00/22] [GIT PULL][3.8] tracing: updates Steven Rostedt
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