Messages in this thread | | | Date | Tue, 6 Jan 2009 14:47:40 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 2/3] ring-buffer: rename debugfs file tracing_on to writing_enabled |
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On Tue, 06 Jan 2009 17:33:39 -0500 Steven Rostedt <rostedt@goodmis.org> wrote:
> From: Steven Rostedt <srostedt@redhat.com> > > Impact: clean up > > The debugfs file name tracing_on is confusing since there is also > a tracing_enabled. When a tracer is added to current_tracer and > tracing_enabled is set to 1, then the tracer will start tracing. > The current file tracing_on, if set to 1, will allow writing to > the ring buffers. If tracing_on is set to 0 then the ring buffers > are read only, and any attempt by the tracers to write to the > ring buffers will fail. > > But the name tracing_on confuses both developers and users. > This patch renames it to 'writing_enabled'. This is exactly what > the file does. When set to 1, the ring buffers have writing enabled > and when set to 0, the ring buffers can not be written to. > > The tracers do not get any call backs called or other notification > that the ring buffers have been set to read only, except when they > attempt to write to the ring buffers, that write will fail. > > Note: it is a requirement that any tracer that uses the ring buffers > must handle a failure to write to the ring buffers, since the ring buffers > may be disabled for any number of reasons. > > Signed-off-by: Steven Rostedt <srostedt@redhat.com> > --- > kernel/trace/ring_buffer.c | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index a9d9760..dba6876 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -2514,10 +2514,11 @@ static __init int rb_init_debugfs(void) > > d_tracer = tracing_init_dentry(); > > - entry = debugfs_create_file("tracing_on", 0644, d_tracer, > + entry = debugfs_create_file("writing_enabled", 0644, d_tracer, > &ring_buffer_flags, &rb_simple_fops); > if (!entry) > - pr_warning("Could not create debugfs 'tracing_on' entry\n"); > + pr_warning("Could not create debugfs" > + " 'writing_enabled' entry\n"); > > return 0; > }
There's no corresponding documentation update needed?
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