diff mbox series

[v3,25/25] context_tracking, rcu: Rename rcu_dyntick trace event into rcu_watching

Message ID 20240724144325.3307148-26-vschneid@redhat.com (mailing list archive)
State New, archived
Headers show
Series context_tracking, rcu: Spring cleaning of dynticks references | expand

Commit Message

Valentin Schneider July 24, 2024, 2:43 p.m. UTC
The "rcu_dyntick" naming convention has been turned into "rcu_watching" for
all helpers now, align the trace event to that.

To add to the confusion, the strings passed to the trace event are now
reversed: when RCU "starts" the dyntick / EQS state, it "stops" watching.

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
---
 include/trace/events/rcu.h | 16 ++++++++--------
 kernel/context_tracking.c  | 10 +++++-----
 2 files changed, 13 insertions(+), 13 deletions(-)

Comments

Frederic Weisbecker July 25, 2024, 12:39 p.m. UTC | #1
Le Wed, Jul 24, 2024 at 04:43:25PM +0200, Valentin Schneider a écrit :
> The "rcu_dyntick" naming convention has been turned into "rcu_watching" for
> all helpers now, align the trace event to that.
> 
> To add to the confusion, the strings passed to the trace event are now
> reversed: when RCU "starts" the dyntick / EQS state, it "stops" watching.
> 
> Signed-off-by: Valentin Schneider <vschneid@redhat.com>
> ---
>  include/trace/events/rcu.h | 16 ++++++++--------
>  kernel/context_tracking.c  | 10 +++++-----
>  2 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
> index 4066b6d51e46a..e51ef658437f0 100644
> --- a/include/trace/events/rcu.h
> +++ b/include/trace/events/rcu.h
> @@ -466,40 +466,40 @@ TRACE_EVENT(rcu_stall_warning,
>  /*
>   * Tracepoint for dyntick-idle entry/exit events.  These take 2 strings
>   * as argument:
> - * polarity: "Start", "End", "StillNonIdle" for entering, exiting or still not
> + * polarity: "Start", "End", "StillWatching" for entering, exiting or still not
>   *            being in dyntick-idle mode.
>   * context: "USER" or "IDLE" or "IRQ".

So that should be:

 * polarity: "Start", "End", "StillWatching" for exiting, entering or still not
             being in EQS mode.

Right?

Other than that:

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Valentin Schneider July 25, 2024, 2:47 p.m. UTC | #2
On 25/07/24 14:39, Frederic Weisbecker wrote:
> Le Wed, Jul 24, 2024 at 04:43:25PM +0200, Valentin Schneider a écrit :
>> The "rcu_dyntick" naming convention has been turned into "rcu_watching" for
>> all helpers now, align the trace event to that.
>>
>> To add to the confusion, the strings passed to the trace event are now
>> reversed: when RCU "starts" the dyntick / EQS state, it "stops" watching.
>>
>> Signed-off-by: Valentin Schneider <vschneid@redhat.com>
>> ---
>>  include/trace/events/rcu.h | 16 ++++++++--------
>>  kernel/context_tracking.c  | 10 +++++-----
>>  2 files changed, 13 insertions(+), 13 deletions(-)
>>
>> diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
>> index 4066b6d51e46a..e51ef658437f0 100644
>> --- a/include/trace/events/rcu.h
>> +++ b/include/trace/events/rcu.h
>> @@ -466,40 +466,40 @@ TRACE_EVENT(rcu_stall_warning,
>>  /*
>>   * Tracepoint for dyntick-idle entry/exit events.  These take 2 strings
>>   * as argument:
>> - * polarity: "Start", "End", "StillNonIdle" for entering, exiting or still not
>> + * polarity: "Start", "End", "StillWatching" for entering, exiting or still not
>>   *            being in dyntick-idle mode.
>>   * context: "USER" or "IDLE" or "IRQ".
>
> So that should be:
>
>  * polarity: "Start", "End", "StillWatching" for exiting, entering or still not
>              being in EQS mode.
>
> Right?
>

Yep that's better, thanks!

> Other than that:
>
> Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
diff mbox series

Patch

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 4066b6d51e46a..e51ef658437f0 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -466,40 +466,40 @@  TRACE_EVENT(rcu_stall_warning,
 /*
  * Tracepoint for dyntick-idle entry/exit events.  These take 2 strings
  * as argument:
- * polarity: "Start", "End", "StillNonIdle" for entering, exiting or still not
+ * polarity: "Start", "End", "StillWatching" for entering, exiting or still not
  *            being in dyntick-idle mode.
  * context: "USER" or "IDLE" or "IRQ".
  * NMIs nested in IRQs are inferred with nesting > 1 in IRQ context.
  *
  * These events also take a pair of numbers, which indicate the nesting
  * depth before and after the event of interest, and a third number that is
- * the ->dynticks counter.  Note that task-related and interrupt-related
+ * the RCU_WATCHING counter.  Note that task-related and interrupt-related
  * events use two separate counters, and that the "++=" and "--=" events
  * for irq/NMI will change the counter by two, otherwise by one.
  */
-TRACE_EVENT_RCU(rcu_dyntick,
+TRACE_EVENT_RCU(rcu_watching,
 
-	TP_PROTO(const char *polarity, long oldnesting, long newnesting, int dynticks),
+	TP_PROTO(const char *polarity, long oldnesting, long newnesting, int counter),
 
-	TP_ARGS(polarity, oldnesting, newnesting, dynticks),
+	TP_ARGS(polarity, oldnesting, newnesting, counter),
 
 	TP_STRUCT__entry(
 		__field(const char *, polarity)
 		__field(long, oldnesting)
 		__field(long, newnesting)
-		__field(int, dynticks)
+		__field(int, counter)
 	),
 
 	TP_fast_assign(
 		__entry->polarity = polarity;
 		__entry->oldnesting = oldnesting;
 		__entry->newnesting = newnesting;
-		__entry->dynticks = dynticks;
+		__entry->counter = counter;
 	),
 
 	TP_printk("%s %lx %lx %#3x", __entry->polarity,
 		  __entry->oldnesting, __entry->newnesting,
-		  __entry->dynticks & 0xfff)
+		  __entry->counter & 0xfff)
 );
 
 /*
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index e64bb746cd9b3..152b485a62db5 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -137,7 +137,7 @@  static void noinstr ct_kernel_exit(bool user, int offset)
 
 	instrumentation_begin();
 	lockdep_assert_irqs_disabled();
-	trace_rcu_dyntick(TPS("Start"), ct_nesting(), 0, ct_rcu_watching());
+	trace_rcu_watching(TPS("End"), ct_nesting(), 0, ct_rcu_watching());
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	rcu_preempt_deferred_qs(current);
 
@@ -182,7 +182,7 @@  static void noinstr ct_kernel_enter(bool user, int offset)
 	// instrumentation for the noinstr ct_kernel_enter_state()
 	instrument_atomic_write(&ct->state, sizeof(ct->state));
 
-	trace_rcu_dyntick(TPS("End"), ct_nesting(), 1, ct_rcu_watching());
+	trace_rcu_watching(TPS("Start"), ct_nesting(), 1, ct_rcu_watching());
 	WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
 	WRITE_ONCE(ct->nesting, 1);
 	WARN_ON_ONCE(ct_nmi_nesting());
@@ -219,7 +219,7 @@  void noinstr ct_nmi_exit(void)
 	 * leave it in non-RCU-idle state.
 	 */
 	if (ct_nmi_nesting() != 1) {
-		trace_rcu_dyntick(TPS("--="), ct_nmi_nesting(), ct_nmi_nesting() - 2,
+		trace_rcu_watching(TPS("--="), ct_nmi_nesting(), ct_nmi_nesting() - 2,
 				  ct_rcu_watching());
 		WRITE_ONCE(ct->nmi_nesting, /* No store tearing. */
 			   ct_nmi_nesting() - 2);
@@ -228,7 +228,7 @@  void noinstr ct_nmi_exit(void)
 	}
 
 	/* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */
-	trace_rcu_dyntick(TPS("Startirq"), ct_nmi_nesting(), 0, ct_rcu_watching());
+	trace_rcu_watching(TPS("Endirq"), ct_nmi_nesting(), 0, ct_rcu_watching());
 	WRITE_ONCE(ct->nmi_nesting, 0); /* Avoid store tearing. */
 
 	// instrumentation for the noinstr ct_kernel_exit_state()
@@ -294,7 +294,7 @@  void noinstr ct_nmi_enter(void)
 		instrumentation_begin();
 	}
 
-	trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="),
+	trace_rcu_watching(incby == 1 ? TPS("Startirq") : TPS("++="),
 			  ct_nmi_nesting(),
 			  ct_nmi_nesting() + incby, ct_rcu_watching());
 	instrumentation_end();