On Tue, 4 Dec 2018 at 18:26, Steven Rostedt <rost...@goodmis.org> wrote:
>
> On Tue, 4 Dec 2018 11:12:43 +0000
> Will Deacon <will.dea...@arm.com> wrote:
>
> > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> > > index 8ef9fc226037..42e89397778b 100644
> > > --- a/kernel/trace/ftrace.c
> > > +++ b/kernel/trace/ftrace.c
> > > @@ -2393,11 +2393,14 @@ void __weak ftrace_replace_code(int enable)
> > > {
> > > struct dyn_ftrace *rec;
> > > struct ftrace_page *pg;
> > > + bool schedulable;
> > > int failed;
> > >
> > > if (unlikely(ftrace_disabled))
> > > return;
> > >
> > > + schedulable = !irqs_disabled() & !preempt_count();
> >
> > Looks suspiciously like a bitwise preemptible() to me!
>
> Ah, thanks. Yeah, that should have been &&. But what did you expect.
> I didn't even compile this ;-)
>
> >
> > > +
> > > do_for_each_ftrace_rec(pg, rec) {
> > >
> > > if (rec->flags & FTRACE_FL_DISABLED)
> > > @@ -2409,6 +2412,8 @@ void __weak ftrace_replace_code(int enable)
> > > /* Stop processing */
> > > return;
> > > }
> > > + if (schedulable)
> > > + cond_resched();
> > > } while_for_each_ftrace_rec();
> > > }
> >
> > If this solves the problem in core code, them I'm all for it. Otherwise, I
> > was thinking of rolling our own ftrace_replace_code() for arm64, but that's
> > going to involve a fair amount of duplication.
> >
>
> If it does, then I'll add it. Or take a patch for it ;-)
I tested your patch. it worked.
I'll send a patch shortly.
Cheers,
Anders
