Messages in this thread | | | Date | Mon, 14 Mar 2022 13:06:41 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 2/3] preempt/dynamic: Introduce preempt mode accessors |
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On Mon, Mar 14, 2022 at 03:44:39PM +0100, Marco Elver wrote: > On Mon, 14 Mar 2022 at 14:37, Frederic Weisbecker <frederic@kernel.org> wrote: > > > > From: Valentin Schneider <valentin.schneider@arm.com> > > > > CONFIG_PREEMPT{_NONE, _VOLUNTARY} designate either: > > o The build-time preemption model when !PREEMPT_DYNAMIC > > o The default boot-time preemption model when PREEMPT_DYNAMIC > > > > IOW, using those on PREEMPT_DYNAMIC kernels is meaningless - the actual > > model could have been set to something else by the "preempt=foo" cmdline > > parameter. > > > > Introduce a set of helpers to determine the actual preemption mode used by > > the live kernel. > > > > Suggested-by: Marco Elver <elver@google.com> > > Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> > > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > > Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> > > Cc: Joel Fernandes <joel@joelfernandes.org> > > Cc: Boqun Feng <boqun.feng@gmail.com> > > Cc: Peter Zijlstra <peterz@infradead.org> > > Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> > > --- > > include/linux/sched.h | 16 ++++++++++++++++ > > kernel/sched/core.c | 11 +++++++++++ > > 2 files changed, 27 insertions(+) > > > > diff --git a/include/linux/sched.h b/include/linux/sched.h > > index 508b91d57470..d348e886e4d0 100644 > > --- a/include/linux/sched.h > > +++ b/include/linux/sched.h > > @@ -2096,6 +2096,22 @@ static inline void cond_resched_rcu(void) > > #endif > > } > > > > +#ifdef CONFIG_PREEMPT_DYNAMIC > > + > > +extern bool preempt_mode_none(void); > > +extern bool preempt_mode_voluntary(void); > > +extern bool preempt_mode_full(void); > > + > > +#else > > + > > +#define preempt_mode_none() IS_ENABLED(CONFIG_PREEMPT_NONE) > > +#define preempt_mode_voluntary() IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY) > > +#define preempt_mode_full() IS_ENABLED(CONFIG_PREEMPT) > > + > > Shame this was somehow forgotten. > There was a v3 of this patch that fixed a bunch of things (e.g. making > these proper functions so all builds error if accidentally used in > #if). > > https://lore.kernel.org/lkml/20211112185203.280040-3-valentin.schneider@arm.com/ > > Is it also possible to take all the rest of that series (all 4 > patches) from Valentin?
Me, I am assuming that #2/3 is an experimental test so that I am able to easily whack this series over the head with rcutorture. ;-)
Thanx, Paul
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