Re: [PATCH][GIT PULL][v2.6.35] tracing/events: Convert format output to seq_file

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 2010-06-04 at 10:11 +0800, Li Zefan wrote:
> > +static void *f_start(struct seq_file *m, loff_t *pos)
> > +{
> > +	loff_t l = 1;
> > +	void *p;
> > +
> > +	/* Start by showing the header */
> > +	if (!*pos) {
> > +		(*pos)++;
> 
> We shoudn't increment *pos in start() handler. It's a common mistake when
> using seqfile. 

And a common mistake I do :-p

I'll rebase it with the fix.

> 
> What we need to do in start() is move the pointer to postion *pos.

So the rest is OK then? All that is needed is the removal of *pos++ ?

Thanks,

-- Steve

> 
> > +		return (void *)FORMAT_HEADER;
> >  	}
> >  
> > -	if (r)
> > -		r = trace_seq_printf(s, "\nprint fmt: %s\n",
> > -				call->print_fmt);
> > +	p = (void *)FORMAT_HEADER;
> > +	do {
> > +		p = f_next(m, p, &l);
> > +	} while (p && l < *pos);
> >  
> > -	if (!r) {
> > -		/*
> > -		 * ug!  The format output is bigger than a PAGE!!
> > -		 */
> > -		buf = "FORMAT TOO BIG\n";
> > -		r = simple_read_from_buffer(ubuf, cnt, ppos,
> > -					      buf, strlen(buf));
> > -		goto out;
> > +	return p;
> > +}