| Message ID | 20241002145738.38226-4-frederic@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | rcu: Fix yet another wake up from offline related issue | expand |
Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit : > Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier > blind spot. Report any potential misuse. > > Reported-by: Paul E. McKenney <paulmck@kernel.org> > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > --- > kernel/rcu/tree.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index a60616e69b66..36070b6bf4a1 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) > head->func = func; > head->next = NULL; > kasan_record_aux_stack_noalloc(head); > + > local_irq_save(flags); > rdp = this_cpu_ptr(&rcu_data); > + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline > CPU!"); This should be !rcu_rdp_cpu_online(rdp) Sigh... > + > lazy = lazy_in && !rcu_async_should_hurry(); > > /* Add the callback to our list. */ > -- > 2.46.0 > >
On Wed, Oct 02, 2024 at 05:00:03PM +0200, Frederic Weisbecker wrote: > Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit : > > Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier > > blind spot. Report any potential misuse. > > > > Reported-by: Paul E. McKenney <paulmck@kernel.org> > > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > > --- > > kernel/rcu/tree.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > index a60616e69b66..36070b6bf4a1 100644 > > --- a/kernel/rcu/tree.c > > +++ b/kernel/rcu/tree.c > > @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) > > head->func = func; > > head->next = NULL; > > kasan_record_aux_stack_noalloc(head); > > + > > local_irq_save(flags); > > rdp = this_cpu_ptr(&rcu_data); > > + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline > > CPU!"); > > This should be !rcu_rdp_cpu_online(rdp) > > Sigh... I am pulling this in for testing with this change, thank you! Thanx, Paul > > + > > lazy = lazy_in && !rcu_async_should_hurry(); > > > > /* Add the callback to our list. */ > > -- > > 2.46.0 > > > >
On 10/2/2024 8:30 PM, Frederic Weisbecker wrote: > Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit : >> Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier >> blind spot. Report any potential misuse. >> >> Reported-by: Paul E. McKenney <paulmck@kernel.org> >> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> >> --- >> kernel/rcu/tree.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c >> index a60616e69b66..36070b6bf4a1 100644 >> --- a/kernel/rcu/tree.c >> +++ b/kernel/rcu/tree.c >> @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) >> head->func = func; >> head->next = NULL; >> kasan_record_aux_stack_noalloc(head); >> + >> local_irq_save(flags); >> rdp = this_cpu_ptr(&rcu_data); >> + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline >> CPU!"); > > This should be !rcu_rdp_cpu_online(rdp) > With this patch series, 600 mins RCU torture overnight testing completed without failures at my end. - Neeraj > Sigh... > >> + >> lazy = lazy_in && !rcu_async_should_hurry(); >> >> /* Add the callback to our list. */ >> -- >> 2.46.0 >> >>
On Tue, Oct 08, 2024 at 07:03:50PM -0700, Paul E. McKenney wrote: > On Wed, Oct 02, 2024 at 05:00:03PM +0200, Frederic Weisbecker wrote: > > Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit : > > > Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier > > > blind spot. Report any potential misuse. > > > > > > Reported-by: Paul E. McKenney <paulmck@kernel.org> > > > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > > > --- > > > kernel/rcu/tree.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > index a60616e69b66..36070b6bf4a1 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) > > > head->func = func; > > > head->next = NULL; > > > kasan_record_aux_stack_noalloc(head); > > > + > > > local_irq_save(flags); > > > rdp = this_cpu_ptr(&rcu_data); > > > + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline > > > CPU!"); > > > > This should be !rcu_rdp_cpu_online(rdp) > > > > Sigh... > > I am pulling this in for testing with this change, thank you! And: Tested-by: Paul E. McKenney <paulmck@kernel.org> > Thanx, Paul > > > > + > > > lazy = lazy_in && !rcu_async_should_hurry(); > > > > > > /* Add the callback to our list. */ > > > -- > > > 2.46.0 > > > > > > >
On Wed, Oct 9, 2024 at 11:13 AM Paul E. McKenney <paulmck@kernel.org> wrote: > > On Tue, Oct 08, 2024 at 07:03:50PM -0700, Paul E. McKenney wrote: > > On Wed, Oct 02, 2024 at 05:00:03PM +0200, Frederic Weisbecker wrote: > > > Le Wed, Oct 02, 2024 at 04:57:38PM +0200, Frederic Weisbecker a écrit : > > > > Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier > > > > blind spot. Report any potential misuse. > > > > > > > > Reported-by: Paul E. McKenney <paulmck@kernel.org> > > > > Signed-off-by: Frederic Weisbecker <frederic@kernel.org> > > > > --- > > > > kernel/rcu/tree.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > > index a60616e69b66..36070b6bf4a1 100644 > > > > --- a/kernel/rcu/tree.c > > > > +++ b/kernel/rcu/tree.c > > > > @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) > > > > head->func = func; > > > > head->next = NULL; > > > > kasan_record_aux_stack_noalloc(head); > > > > + > > > > local_irq_save(flags); > > > > rdp = this_cpu_ptr(&rcu_data); > > > > + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline > > > > CPU!"); > > > > > > This should be !rcu_rdp_cpu_online(rdp) > > > > > > Sigh... > > > > I am pulling this in for testing with this change, thank you! > > And: > > Tested-by: Paul E. McKenney <paulmck@kernel.org> With the correction, Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> thanks, - Joel
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a60616e69b66..36070b6bf4a1 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3084,8 +3084,11 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) head->func = func; head->next = NULL; kasan_record_aux_stack_noalloc(head); + local_irq_save(flags); rdp = this_cpu_ptr(&rcu_data); + RCU_LOCKDEP_WARN(rcu_rdp_cpu_online(rdp), "Callback enqueued on offline CPU!"); + lazy = lazy_in && !rcu_async_should_hurry(); /* Add the callback to our list. */
Callbacks enqueued after rcutree_report_cpu_dead() fall into RCU barrier blind spot. Report any potential misuse. Reported-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> --- kernel/rcu/tree.c | 3 +++ 1 file changed, 3 insertions(+)