[PATCH v2 05/11] cpuidle: Move trace_cpu_idle() into generic code

From: Peter Zijlstra
Date: Fri Aug 21 2020 - 04:57:23 EST


Remove trace_cpu_idle() from the arch_cpu_idle() implementations and
put it in the generic code, right before disabling RCU. Gets rid of
more trace_*_rcuidle() users.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Tested-by: Marco Elver <elver@xxxxxxxxxx>
---
arch/arm/mach-omap2/pm34xx.c | 4 ----
arch/arm64/kernel/process.c | 2 --
arch/s390/kernel/idle.c | 3 +--
arch/x86/kernel/process.c | 4 ----
kernel/sched/idle.c | 3 +++
5 files changed, 4 insertions(+), 12 deletions(-)

--- a/arch/arm/mach-omap2/pm34xx.c
+++ b/arch/arm/mach-omap2/pm34xx.c
@@ -298,11 +298,7 @@ static void omap3_pm_idle(void)
if (omap_irq_pending())
return;

- trace_cpu_idle_rcuidle(1, smp_processor_id());
-
omap_sram_idle();
-
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}

#ifdef CONFIG_SUSPEND
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -123,10 +123,8 @@ void arch_cpu_idle(void)
* This should do all the clock switching and wait for interrupt
* tricks
*/
- trace_cpu_idle_rcuidle(1, smp_processor_id());
cpu_do_idle();
local_irq_enable();
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}

#ifdef CONFIG_HOTPLUG_CPU
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -33,14 +33,13 @@ void enabled_wait(void)
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
clear_cpu_flag(CIF_NOHZ_DELAY);

- trace_cpu_idle_rcuidle(1, smp_processor_id());
local_irq_save(flags);
/* Call the assembler magic in entry.S */
psw_idle(idle, psw_mask);
local_irq_restore(flags);
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());

/* Account time spent with enabled wait psw loaded as idle time. */
+ /* XXX seqcount has tracepoints that require RCU */
write_seqcount_begin(&idle->seqcount);
idle_time = idle->clock_idle_exit - idle->clock_idle_enter;
idle->clock_idle_enter = idle->clock_idle_exit = 0ULL;
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -684,9 +684,7 @@ void arch_cpu_idle(void)
*/
void __cpuidle default_idle(void)
{
- trace_cpu_idle_rcuidle(1, smp_processor_id());
safe_halt();
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
#if defined(CONFIG_APM_MODULE) || defined(CONFIG_HALTPOLL_CPUIDLE_MODULE)
EXPORT_SYMBOL(default_idle);
@@ -792,7 +790,6 @@ static int prefer_mwait_c1_over_halt(con
static __cpuidle void mwait_idle(void)
{
if (!current_set_polling_and_test()) {
- trace_cpu_idle_rcuidle(1, smp_processor_id());
if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) {
mb(); /* quirk */
clflush((void *)&current_thread_info()->flags);
@@ -804,7 +801,6 @@ static __cpuidle void mwait_idle(void)
__sti_mwait(0, 0);
else
local_irq_enable();
- trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
} else {
local_irq_enable();
}
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -91,11 +91,14 @@ void __cpuidle default_idle_call(void)
if (current_clr_polling_and_test()) {
local_irq_enable();
} else {
+
+ trace_cpu_idle(1, smp_processor_id());
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
rcu_idle_exit();
start_critical_timings();
+ trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
}
}