Commit e67198cc authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Paul E. McKenney
Browse files

context_tracking: Take idle eqs entrypoints over RCU 



The RCU dynticks counter is going to be merged into the context tracking
subsystem. Start with moving the idle extended quiescent states
entrypoints to context tracking. For now those are dumb redirections to
existing RCU calls.

[ paulmck: Apply kernel test robot feedback. ]

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Nicolas Saenz Julienne <nsaenz@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: Phil Auld <pauld@redhat.com>
Cc: Paul Gortmaker<paul.gortmaker@windriver.com>
Cc: Alex Belits <abelits@marvell.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Reviewed-by: default avatarNicolas Saenz Julienne <nsaenzju@redhat.com>
Tested-by: default avatarNicolas Saenz Julienne <nsaenzju@redhat.com>
parent 24a9c541

Documentation/RCU/stallwarn.rst

+2 −2
Original line number Diff line number Diff line
@@ -97,8 +97,8 @@ warnings: 
	which will include additional debugging information.



-	A low-level kernel issue that either fails to invoke one of the

	variants of rcu_user_enter(), rcu_user_exit(), rcu_idle_enter(),

	rcu_idle_exit(), rcu_irq_enter(), or rcu_irq_exit() on the one

	variants of rcu_user_enter(), rcu_user_exit(), ct_idle_enter(),

	ct_idle_exit(), rcu_irq_enter(), or rcu_irq_exit() on the one

	hand, or that invokes one of them too many times on the other.

	Historically, the most frequent issue has been an omission

	of either irq_enter() or irq_exit(), which in turn invoke

arch/arm/mach-imx/cpuidle-imx6q.c

+3 −2
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 * Copyright (C) 2012 Freescale Semiconductor, Inc.

 */



#include <linux/context_tracking.h>

#include <linux/cpuidle.h>

#include <linux/module.h>

#include <asm/cpuidle.h>
@@ -24,9 +25,9 @@ static int imx6q_enter_wait(struct cpuidle_device *dev, 
		imx6_set_lpm(WAIT_UNCLOCKED);

	raw_spin_unlock(&cpuidle_lock);



	rcu_idle_enter();

	ct_idle_enter();

	cpu_do_idle();

	rcu_idle_exit();

	ct_idle_exit();



	raw_spin_lock(&cpuidle_lock);

	if (num_idle_cpus-- == num_online_cpus())

drivers/acpi/processor_idle.c

+3 −2
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/minmax.h>

#include <linux/perf_event.h>

#include <acpi/processor.h>

#include <linux/context_tracking.h>



/*

 * Include the apic definitions for x86 to have the APIC timer related defines
@@ -647,11 +648,11 @@ static int acpi_idle_enter_bm(struct cpuidle_driver *drv, 
		raw_spin_unlock(&c3_lock);

	}



	rcu_idle_enter();

	ct_idle_enter();



	acpi_idle_do_entry(cx);



	rcu_idle_exit();

	ct_idle_exit();



	/* Re-enable bus master arbitration */

	if (dis_bm) {

drivers/cpuidle/cpuidle.c

+5 −4
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/suspend.h>

#include <linux/tick.h>

#include <linux/mmu_context.h>

#include <linux/context_tracking.h>

#include <trace/events/power.h>



#include "cpuidle.h"
@@ -150,12 +151,12 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv, 
	 */

	stop_critical_timings();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

		rcu_idle_enter();

		ct_idle_enter();

	target_state->enter_s2idle(dev, drv, index);

	if (WARN_ON_ONCE(!irqs_disabled()))

		local_irq_disable();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

		rcu_idle_exit();

		ct_idle_exit();

	tick_unfreeze();

	start_critical_timings();
@@ -233,10 +234,10 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, 


	stop_critical_timings();

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

		rcu_idle_enter();

		ct_idle_enter();

	entered_state = target_state->enter(dev, drv, index);

	if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE))

		rcu_idle_exit();

		ct_idle_exit();

	start_critical_timings();



	sched_clock_idle_wakeup_event();

include/linux/context_tracking.h

+8 −0
Original line number Diff line number Diff line
@@ -119,4 +119,12 @@ extern void context_tracking_init(void); 
static inline void context_tracking_init(void) { }

#endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */



#ifdef CONFIG_CONTEXT_TRACKING_IDLE

extern void ct_idle_enter(void);

extern void ct_idle_exit(void);

#else

static inline void ct_idle_enter(void) { }

static inline void ct_idle_exit(void) { }

#endif /* !CONFIG_CONTEXT_TRACKING_IDLE */



#endif