Re: [PATCH 1/1] Fix: trace sched switch start/stop racy updates

From: Paul E. McKenney
Date: Tue Aug 20 2019 - 16:53:38 EST


On Tue, Aug 20, 2019 at 10:39:39PM +0200, Peter Zijlstra wrote:
> On Tue, Aug 20, 2019 at 01:31:35PM -0700, Paul E. McKenney wrote:
> > On Tue, Aug 20, 2019 at 04:01:16PM +0200, Peter Zijlstra wrote:
>
> > > We really should get the compiler folks to give us a
> > > -fno-pointer-provenance. Waiting on the standards committee to get their
> > > act together seems unlikely, esp. given that some people actually seem
> > > to _want_ this nonsense :/
> >
> > The reason that they want it is to enable some significant optimizations
> > in numerical code on the one hand and in heavily templated C++ code on
> > the other. Neither of which has much bearing on kernel code.
> >
> > Interested in coming to the next C standards committee meeting in October
> > to help me push for this? ;-)
>
> How about we try and get some compiler folks together at plumbers and
> bribe them with beer? Once we have our compiler knob, we happy :-)

C'mon, Peter! Where is your sense of self-destruction??? ;-)

But yes, if nothing else there is a Toolchains MC [1]. Which happens to
have a topic entitled "Potential impact/benefit/detriment of recently
developed GCC optimizations on the kernel", now that you mention it.
Looking forward to seeing you in Lisbon!

Thanx, Paul

[1] https://linuxplumbersconf.org/event/4/sessions/45/#20190909