On Tue, Sep 03, 2019 at 01:04:46PM -0700, Paul E. McKenney wrote: > On Fri, Aug 30, 2019 at 12:23:48PM -0400, Joel Fernandes (Google) wrote: > > The dyntick-idle traces are a bit confusing. This patch makes it simpler > > and adds some missing cases such as EQS-enter due to user vs idle mode. > > > > Following are the changes: > > (1) Add a new context field to trace_rcu_dyntick tracepoint. This > > context field can be "USER", "IDLE" or "IRQ". > > > > (2) Remove the "++=" and "--=" strings and replace them with > > "StillNonIdle". This is much easier on the eyes, and the -- and ++ > > are easily apparent in the dynticks_nesting counters we are printing > > anyway. > > > > This patch is based on the previous patches to simplify rcu_dyntick > > counters [1] and with these traces, I have verified the counters are > > working properly. > > > > [1] > > Link: https://lore.kernel.org/patchwork/patch/1120021/ > > Link: https://lore.kernel.org/patchwork/patch/1120022/ > > > > Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx> > > This looks fine, but depends on the earlier patch. The earlier patch looks Ok? Did not see any review comments. That is just a revert of an old commit. thanks, - Joel > Thanx, Paul > > > --- > > include/trace/events/rcu.h | 13 ++++++++----- > > kernel/rcu/tree.c | 19 +++++++++++++------ > > 2 files changed, 21 insertions(+), 11 deletions(-) > > > > diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h > > index 66122602bd08..474c1f7e7104 100644 > > --- a/include/trace/events/rcu.h > > +++ b/include/trace/events/rcu.h > > @@ -449,12 +449,14 @@ TRACE_EVENT_RCU(rcu_fqs, > > */ > > TRACE_EVENT_RCU(rcu_dyntick, > > > > - TP_PROTO(const char *polarity, long oldnesting, long newnesting, atomic_t dynticks), > > + TP_PROTO(const char *polarity, const char *context, long oldnesting, > > + long newnesting, atomic_t dynticks), > > > > - TP_ARGS(polarity, oldnesting, newnesting, dynticks), > > + TP_ARGS(polarity, context, oldnesting, newnesting, dynticks), > > > > TP_STRUCT__entry( > > __field(const char *, polarity) > > + __field(const char *, context) > > __field(long, oldnesting) > > __field(long, newnesting) > > __field(int, dynticks) > > @@ -462,14 +464,15 @@ TRACE_EVENT_RCU(rcu_dyntick, > > > > TP_fast_assign( > > __entry->polarity = polarity; > > + __entry->context = context; > > __entry->oldnesting = oldnesting; > > __entry->newnesting = newnesting; > > __entry->dynticks = atomic_read(&dynticks); > > ), > > > > - TP_printk("%s %lx %lx %#3x", __entry->polarity, > > - __entry->oldnesting, __entry->newnesting, > > - __entry->dynticks & 0xfff) > > + TP_printk("%s %s %lx %lx %#3x", __entry->polarity, > > + __entry->context, __entry->oldnesting, __entry->newnesting, > > + __entry->dynticks & 0xfff) > > ); > > > > /* > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > index 417dd00b9e87..463407762b5a 100644 > > --- a/kernel/rcu/tree.c > > +++ b/kernel/rcu/tree.c > > @@ -533,7 +533,8 @@ static void rcu_eqs_enter(bool user) > > } > > > > lockdep_assert_irqs_disabled(); > > - trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, rdp->dynticks); > > + trace_rcu_dyntick(TPS("Start"), (user ? TPS("USER") : TPS("IDLE")), > > + rdp->dynticks_nesting, 0, rdp->dynticks); > > WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current)); > > rdp = this_cpu_ptr(&rcu_data); > > do_nocb_deferred_wakeup(rdp); > > @@ -606,14 +607,17 @@ static __always_inline void rcu_nmi_exit_common(bool irq) > > * leave it in non-RCU-idle state. > > */ > > if (rdp->dynticks_nmi_nesting != 1) { > > - trace_rcu_dyntick(TPS("--="), rdp->dynticks_nmi_nesting, rdp->dynticks_nmi_nesting - 2, rdp->dynticks); > > + trace_rcu_dyntick(TPS("StillNonIdle"), TPS("IRQ"), > > + rdp->dynticks_nmi_nesting, > > + rdp->dynticks_nmi_nesting - 2, rdp->dynticks); > > WRITE_ONCE(rdp->dynticks_nmi_nesting, /* No store tearing. */ > > rdp->dynticks_nmi_nesting - 2); > > return; > > } > > > > /* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */ > > - trace_rcu_dyntick(TPS("Startirq"), rdp->dynticks_nmi_nesting, 0, rdp->dynticks); > > + trace_rcu_dyntick(TPS("Start"), TPS("IRQ"), rdp->dynticks_nmi_nesting, > > + 0, rdp->dynticks); > > WRITE_ONCE(rdp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */ > > > > if (irq) > > @@ -700,7 +704,8 @@ static void rcu_eqs_exit(bool user) > > rcu_dynticks_task_exit(); > > rcu_dynticks_eqs_exit(); > > rcu_cleanup_after_idle(); > > - trace_rcu_dyntick(TPS("End"), rdp->dynticks_nesting, 1, rdp->dynticks); > > + trace_rcu_dyntick(TPS("End"), (user ? TPS("USER") : TPS("IDLE")), > > + rdp->dynticks_nesting, 1, rdp->dynticks); > > WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current)); > > WRITE_ONCE(rdp->dynticks_nesting, 1); > > WARN_ON_ONCE(rdp->dynticks_nmi_nesting); > > @@ -787,9 +792,11 @@ static __always_inline void rcu_nmi_enter_common(bool irq) > > rdp->rcu_forced_tick = true; > > tick_dep_set_cpu(rdp->cpu, TICK_DEP_BIT_RCU); > > } > > - trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="), > > - rdp->dynticks_nmi_nesting, > > + > > + trace_rcu_dyntick(incby == 1 ? TPS("End") : TPS("StillNonIdle"), > > + TPS("IRQ"), rdp->dynticks_nmi_nesting, > > rdp->dynticks_nmi_nesting + incby, rdp->dynticks); > > + > > WRITE_ONCE(rdp->dynticks_nmi_nesting, /* Prevent store tearing. */ > > rdp->dynticks_nmi_nesting + incby); > > barrier(); > > -- > > 2.23.0.187.g17f5b7556c-goog > >
