Re: [PATCH 3/3] ftrace: add ability to only trace swapper tasks

From: Steven Rostedt
Date: Thu Dec 04 2008 - 09:46:40 EST



On Thu, 4 Dec 2008, Eric W. Biederman wrote:

> Ingo Molnar <mingo@xxxxxxx> writes:
>
> > * Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> >> > Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx>
> >>
> >> What does this patch actually do? Is swapper currently excluded from
> >> tracing for undisclosed reasons and this patch permits it to be traced?
> >> If so, why was swapper thus excluded? Or am I totally off track?
> >
> >> > +static struct pid * const ftrace_swapper_pid = (struct pid *)1;
> >>
> >> eh?
> >
> > all side-effects of getting rid of the integer based PID namespace and
> > replacing them with struct pid pointers.
>
> Thanks for asking Andrew it looks like an unnecessary side effect.

Well, it was necessary without hacking fork.c ;-)

-- Steve

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