ftrace introduces instability into kernel 2.6.27(-rc2,-rc3)

[Steven Rostedt]

On Mon, 18 Aug 2008, Mathieu Desnoyers wrote:
> > > > 
> > > 
> > > Argh. See text_poke(). It's there exactly for this purpose on x86.
> > 
> > Ouch, I just did. text_poke is quite heavy. It would be interesting to see 
> > that performed on 20,000 locations at one time. I could play with it, but 
> > I'm a bit nervous.
> > 
> 
> It's alread used to modify the LOCK prefixes in alternative.c and did
> not seem to be too slow for that.. it should therefore be ok.

There's a lot more functions than locks ;-)

Anyway, this is only needed after system boot up. But then we do it ever 
time we start or stop tracing. I'll try it out and see if it is noticable.

-- Steve