Messages in this thread | | | Date | Tue, 29 Nov 2011 02:00:48 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 2/4] rcu: Irq nesting is always 0 on rcu_enter_idle_common |
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On Mon, Nov 28, 2011 at 04:29:14PM -0800, Paul E. McKenney wrote: > On Mon, Nov 28, 2011 at 10:24:45PM +0100, Frederic Weisbecker wrote: > > So pass 0 directly as a nesting value on the tracing calls. > > > > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > > Cc: Josh Triplett <josh@joshtriplett.org> > > --- > > kernel/rcutree.c | 5 ++--- > > 1 files changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > > index c2aaadf..b80cb41 100644 > > --- a/kernel/rcutree.c > > +++ b/kernel/rcutree.c > > @@ -350,11 +350,10 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) > > */ > > static void rcu_idle_enter_common(struct rcu_dynticks *rdtp) > > { > > - trace_rcu_dyntick("Start", rdtp->dynticks_nesting); > > + trace_rcu_dyntick("Start", 0); > > if (!idle_cpu(smp_processor_id())) { > > WARN_ON_ONCE(1); /* must be idle task! */ > > - trace_rcu_dyntick("Error on entry: not idle task", > > - rdtp->dynticks_nesting); > > + trace_rcu_dyntick("Error on entry: not idle task", 0); > > ftrace_dump(DUMP_ALL); > > } > > /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */ > > Queued, again updating to work around the mid-air collision. > > Thanx, Paul > > ------------------------------------------------------------------------ > > rcu: Irq nesting is always 0 on rcu_enter_idle_common > > Because tasks don't nest, the ->dyntick_nesting must always be zero upon > entry to rcu_idle_enter_common(). Therefore, pass "0" rather than the > counter itself.
And with a better changelog.
Thanks!
> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Josh Triplett <josh@joshtriplett.org> > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index 54d9b4f..e0f5072 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -350,12 +350,11 @@ static int rcu_implicit_offline_qs(struct rcu_data *rdp) > */ > static void rcu_idle_enter_common(struct rcu_dynticks *rdtp, long long oldval) > { > - trace_rcu_dyntick("Start", oldval, rdtp->dynticks_nesting); > + trace_rcu_dyntick("Start", oldval, 0); > if (!is_idle_task(current)) { > struct task_struct *idle = idle_task(smp_processor_id()); > > - trace_rcu_dyntick("Error on entry: not idle task", > - oldval, rdtp->dynticks_nesting); > + trace_rcu_dyntick("Error on entry: not idle task", oldval, 0); > ftrace_dump(DUMP_ALL); > WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s", > current->pid, current->comm, >
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