diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2023-01-12 20:43:27 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-01-13 11:48:15 +0100 |
| commit | a01353cf1896ea5b8a7bbc5e2b2d38feed8b7aaa (patch) | |
| tree | d481b825921d2e5f4431e3929454f0520ca017ce /kernel/sched/idle.c | |
| parent | 0c5ffc3d7b15978c6b184938cd6b8af06e436424 (diff) | |
cpuidle: Fix ct_idle_*() usage
The whole disable-RCU, enable-IRQS dance is very intricate since
changing IRQ state is traced, which depends on RCU.
Add two helpers for the cpuidle case that mirror the entry code:
ct_cpuidle_enter()
ct_cpuidle_exit()
And fix all the cases where the enter/exit dance was buggy.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org
Diffstat (limited to 'kernel/sched/idle.c')
| -rw-r--r-- | kernel/sched/idle.c | 45 |
1 files changed, 13 insertions, 32 deletions
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index f26ab2675f7d..e924602ec43b 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -51,18 +51,22 @@ __setup("hlt", cpu_idle_nopoll_setup); static noinline int __cpuidle cpu_idle_poll(void) { + instrumentation_begin(); trace_cpu_idle(0, smp_processor_id()); stop_critical_timings(); - ct_idle_enter(); - local_irq_enable(); + ct_cpuidle_enter(); + raw_local_irq_enable(); while (!tif_need_resched() && (cpu_idle_force_poll || tick_check_broadcast_expired())) cpu_relax(); + raw_local_irq_disable(); - ct_idle_exit(); + ct_cpuidle_exit(); start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); + local_irq_enable(); + instrumentation_end(); return 1; } @@ -85,44 +89,21 @@ void __weak arch_cpu_idle(void) */ void __cpuidle default_idle_call(void) { - if (current_clr_polling_and_test()) { - local_irq_enable(); - } else { - + instrumentation_begin(); + if (!current_clr_polling_and_test()) { trace_cpu_idle(1, smp_processor_id()); stop_critical_timings(); - /* - * arch_cpu_idle() is supposed to enable IRQs, however - * we can't do that because of RCU and tracing. - * - * Trace IRQs enable here, then switch off RCU, and have - * arch_cpu_idle() use raw_local_irq_enable(). Note that - * ct_idle_enter() relies on lockdep IRQ state, so switch that - * last -- this is very similar to the entry code. - */ - trace_hardirqs_on_prepare(); - lockdep_hardirqs_on_prepare(); - ct_idle_enter(); - lockdep_hardirqs_on(_THIS_IP_); - + ct_cpuidle_enter(); arch_cpu_idle(); - - /* - * OK, so IRQs are enabled here, but RCU needs them disabled to - * turn itself back on.. funny thing is that disabling IRQs - * will cause tracing, which needs RCU. Jump through hoops to - * make it 'work'. - */ raw_local_irq_disable(); - lockdep_hardirqs_off(_THIS_IP_); - ct_idle_exit(); - lockdep_hardirqs_on(_THIS_IP_); - raw_local_irq_enable(); + ct_cpuidle_exit(); start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); } + local_irq_enable(); + instrumentation_end(); } static int call_cpuidle_s2idle(struct cpuidle_driver *drv, |