Re: [PATCH 2/2] tracing/events: simplify system_enable_read()

[Ingo Molnar <mingo@elte.hu>]

* Andrew Morton <akpm@linux-foundation.org> wrote:

> On Fri, 08 May 2009 10:32:05 +0800
> Li Zefan <lizf@cn.fujitsu.com> wrote:
> 
> > A smarter way to figure out the output of an enable file.
> > 
> > [ Impact: clean up ]
> > 
> > Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> > ---
> >  kernel/trace/trace_events.c |   40 ++++++----------------------------------
> >  1 files changed, 6 insertions(+), 34 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> > index 45f1099..df394bc 100644
> > --- a/kernel/trace/trace_events.c
> > +++ b/kernel/trace/trace_events.c
> > @@ -414,10 +414,11 @@ static ssize_t
> >  system_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
> >  		   loff_t *ppos)
> >  {
> > +	const char set_to_char[4] = { '?', '0', '1', 'X' };
> 
> I always worry when I see this, but gcc does manage to add the missing
> `static' all by itself.  For which versions of gcc that is true I don't
> know.
> 
> > +	buf[0] = set_to_char[set];
> 
> Meh.  Real men do
> 
> 	buf[0] = "?01X"[set];

heh. That deserves a commit ...

	Ingo