Re: [PATCH] perf powerpc: Don't call perf_event_disable from atomic context

From: Jiri Olsa
Date: Wed Oct 05 2016 - 15:53:47 EST


On Wed, Oct 05, 2016 at 10:09:21AM +0200, Jiri Olsa wrote:
> On Tue, Oct 04, 2016 at 03:29:33PM +1100, Michael Ellerman wrote:
>
> SNIP
>
> > Which is where we cope with the possibility that we couldn't emulate the
> > instruction that hit the breakpoint. Seems that is not an issue on x86,
> > or it's handled elsewhere?
> >
> > We should fix emulate_step() if it failed to emulate something it
> > should have, but there will always be the possibility that it fails.
> >
> > Instead of calling perf_event_disable() we could just add a flag to
> > arch_hw_breakpoint that says we hit an error on the event, and block
> > reinstalling it in arch_install_hw_breakpoint().
>
> ok, might be easier.. I'll check on that

so staring on that I think disabling is the right way here..

we need the event to be unscheduled and not scheduled back
again, I don't see better way at the moment

jirka