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

From: Steven Rostedt
Date: Tue Aug 19 2008 - 00:00:41 EST



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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/