Re: [PATCH 3/3] arm64: ftrace: add cond_resched() to func ftrace_make_(call|nop)
From: Steven Rostedt
Date: Tue Dec 04 2018 - 13:23:50 EST
On Tue, 4 Dec 2018 19:07:16 +0100
Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
> > > > + 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 ;-)
> >
> > 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.
>
Thanks. Please add a comment above the schedulable test stating that
some archs call this with interrupts or preemption disabled, but
other archs don't and this can cause a tremendous unneeded latency.
-- Steve