linux-kernel - [PATCH 22/36] arm,smp: Remove trace_.*

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Message-ID: <20220608144517.313931267@infradead.org>
Date:   Wed, 08 Jun 2022 16:27:45 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     peterz@...radead.org
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Subject: [PATCH 22/36] arm,smp: Remove trace_.*_rcuidle() usage

None of these functions should ever be ran with RCU disabled anymore.

Specifically, do_handle_IPI() is only called from handle_IPI() which
explicitly does irq_enter()/irq_exit() which ensures RCU is watching.

The problem with smp_cross_call() was, per commit 7c64cc0531fa ("arm: Use
_rcuidle for smp_cross_call() tracepoints"), that
cpuidle_enter_state_coupled() already had RCU disabled, but that's
long been fixed by commit 1098582a0f6c ("sched,idle,rcu: Push rcu_idle
deeper into the idle path").

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 arch/arm/kernel/smp.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -639,7 +639,7 @@ static void do_handle_IPI(int ipinr)
 	unsigned int cpu = smp_processor_id();
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_entry_rcuidle(ipi_types[ipinr]);
+		trace_ipi_entry(ipi_types[ipinr]);
 
 	switch (ipinr) {
 	case IPI_WAKEUP:
@@ -686,7 +686,7 @@ static void do_handle_IPI(int ipinr)
 	}
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+		trace_ipi_exit(ipi_types[ipinr]);
 }
 
 /* Legacy version, should go away once all irqchips have been converted */
@@ -709,7 +709,7 @@ static irqreturn_t ipi_handler(int irq,
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
 {
-	trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
+	trace_ipi_raise(target, ipi_types[ipinr]);
 	__ipi_send_mask(ipi_desc[ipinr], target);
 }