Messages in this thread | | | Date | Mon, 1 Jul 2013 13:55:50 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 4/4] sched: Consolidate open coded preemptible() checks |
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On Mon, Jul 01, 2013 at 01:20:20PM +0200, Frederic Weisbecker wrote: > On Wed, Jun 26, 2013 at 03:05:11PM +0200, Peter Zijlstra wrote: > > On Thu, Jun 20, 2013 at 10:45:41PM +0200, Frederic Weisbecker wrote: > > > preempt_schedule() and preempt_schedule_context() open > > > code their preemptability checks. > > > > > > Use the standard API instead for consolidation. > > > > > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > > > Cc: Ingo Molnar <mingo@kernel.org> > > > Cc: Li Zhong <zhong@linux.vnet.ibm.com> > > > Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > > > Cc: Peter Zijlstra <peterz@infradead.org> > > > Cc: Steven Rostedt <rostedt@goodmis.org> > > > Cc: Thomas Gleixner <tglx@linutronix.de> > > > Cc: Borislav Petkov <bp@alien8.de> > > > Cc: Alex Shi <alex.shi@intel.com> > > > Cc: Paul Turner <pjt@google.com> > > > Cc: Mike Galbraith <efault@gmx.de> > > > Cc: Vincent Guittot <vincent.guittot@linaro.org> > > > --- > > > kernel/context_tracking.c | 3 +-- > > > kernel/sched/core.c | 4 +--- > > > 2 files changed, 2 insertions(+), 5 deletions(-) > > > > > > diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c > > > index 6667700..08db730 100644 > > > --- a/kernel/context_tracking.c > > > +++ b/kernel/context_tracking.c > > > @@ -88,10 +88,9 @@ void user_enter(void) > > > */ > > > void __sched notrace preempt_schedule_context(void) > > > { > > > - struct thread_info *ti = current_thread_info(); > > > enum ctx_state prev_ctx; > > > > > > - if (likely(ti->preempt_count || irqs_disabled())) > > > + if (likely(!preemptible())) > > > return; > > > > > > > #ifdef CONFIG_PREEMPT_COUNT > > # define preemptible() (preempt_count() == 0 && !irqs_disabled()) > > #else > > # define preemptible() 0 > > #endif > > > > > > Wouldn't that give a problem for !PREEMPT_COUNT? > > preempt_schedule_context() depends on CONFIG_PREEMPT which depends on > CONFIG_PREEMPT_COUNT, so that should work. Or I missed something?
Ah indeed. I just tripped over the fact that its weird to not test irqs_disabled() even though we don't have the preempt count.
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