linux-kernel - Re: [PATCH v5 RESEND] cpuidle: psci: Add trace for PSCI domain idle

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Message-ID: <CAJZ5v0hWNYB69ydM4--GNtLBgG3WS4MT+S10w46883kHnFMMEQ@mail.gmail.com>
Date: Mon, 17 Feb 2025 12:57:07 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Keita Morisaki <keyz@...gle.com>, Ulf Hansson <ulf.hansson@...aro.org>, lpieralisi@...nel.org, 
	sudeep.holla@....com
Cc: linux-kernel@...r.kernel.org, rafael@...nel.org, daniel.lezcano@...aro.org, 
	linux-pm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	rostedt@...dmis.org, mhiramat@...nel.org, mathieu.desnoyers@...icios.com, 
	linux-trace-kernel@...r.kernel.org, aarontian@...gle.com, 
	yimingtseng@...gle.com, Dhruva Gole <d-gole@...com>, Kevin Hilman <khilman@...libre.com>
Subject: Re: [PATCH v5 RESEND] cpuidle: psci: Add trace for PSCI domain idle

+Ulf

On Mon, Feb 10, 2025 at 6:58 AM Keita Morisaki <keyz@...gle.com> wrote:
>
> The trace event cpu_idle provides insufficient information for debugging
> PSCI requests due to lacking access to determined PSCI domain idle
> states. The cpu_idle usually only shows -1, 0, or 1 regardless how many
> idle states the power domain has.
>
> Add new trace events namely psci_domain_idle_enter and
> psci_domain_idle_exit to trace enter and exit events with a determined
> idle state.
>
> These new trace events will help developers debug CPUidle issues on ARM
> systems using PSCI by providing more detailed information about the
> requested idle states.
>
> Signed-off-by: Keita Morisaki <keyz@...gle.com>
> Reviewed-by: Steven Rostedt (Google) <rostedt@...dmis.org>
> Reviewed-by: Dhruva Gole <d-gole@...com>
> Tested-by: Kevin Hilman <khilman@...libre.com>
> ---
> v1->v2: Split the ftrace event into two (psci_domain_idle_(enter|exit))
>         and rephrase the commit message accordingly. Rebased onto the latest.
> v2->v3: Add "Reviewed-by: Steven Rostedt"
> v3->v4: Add the Tested-by label
> v4->v5: Add "Reviewed-by: Dhruva Gole"
>
> Hopefully this patch gets attention from maintainers of
> drivers/cpuidle/cpuidle-psci.c too.

Lorenzo, Sudeep, Ulf, any comments?

>  drivers/cpuidle/cpuidle-psci.c |  3 +++
>  include/trace/events/power.h   | 37 ++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
>
> diff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c
> index 2562dc001fc1..dd8d776d6e39 100644
> --- a/drivers/cpuidle/cpuidle-psci.c
> +++ b/drivers/cpuidle/cpuidle-psci.c
> @@ -25,6 +25,7 @@
>  #include <linux/syscore_ops.h>
>
>  #include <asm/cpuidle.h>
> +#include <trace/events/power.h>
>
>  #include "cpuidle-psci.h"
>  #include "dt_idle_states.h"
> @@ -74,7 +75,9 @@ static __cpuidle int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
>         if (!state)
>                 state = states[idx];
>
> +       trace_psci_domain_idle_enter(dev->cpu, state, s2idle);
>         ret = psci_cpu_suspend_enter(state) ? -1 : idx;
> +       trace_psci_domain_idle_exit(dev->cpu, state, s2idle);
>
>         if (s2idle)
>                 dev_pm_genpd_resume(pd_dev);
> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> index d2349b6b531a..9253e83b9bb4 100644
> --- a/include/trace/events/power.h
> +++ b/include/trace/events/power.h
> @@ -62,6 +62,43 @@ TRACE_EVENT(cpu_idle_miss,
>                 (unsigned long)__entry->state, (__entry->below)?"below":"above")
>  );
>
> +DECLARE_EVENT_CLASS(psci_domain_idle,
> +
> +       TP_PROTO(unsigned int cpu_id, unsigned int state, bool s2idle),
> +
> +       TP_ARGS(cpu_id, state, s2idle),
> +
> +       TP_STRUCT__entry(
> +               __field(u32,            cpu_id)
> +               __field(u32,            state)
> +               __field(bool,           s2idle)
> +       ),
> +
> +       TP_fast_assign(
> +               __entry->cpu_id = cpu_id;
> +               __entry->state = state;
> +               __entry->s2idle = s2idle;
> +       ),
> +
> +       TP_printk("cpu_id=%lu state=0x%lx is_s2idle=%s",
> +                 (unsigned long)__entry->cpu_id, (unsigned long)__entry->state,
> +                 (__entry->s2idle)?"yes":"no")
> +);
> +
> +DEFINE_EVENT(psci_domain_idle, psci_domain_idle_enter,
> +
> +       TP_PROTO(unsigned int cpu_id, unsigned int state, bool s2idle),
> +
> +       TP_ARGS(cpu_id, state, s2idle)
> +);
> +
> +DEFINE_EVENT(psci_domain_idle, psci_domain_idle_exit,
> +
> +       TP_PROTO(unsigned int cpu_id, unsigned int state, bool s2idle),
> +
> +       TP_ARGS(cpu_id, state, s2idle)
> +);
> +
>  TRACE_EVENT(powernv_throttle,
>
>         TP_PROTO(int chip_id, const char *reason, int pmax),
>
> base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04
> --
> 2.48.1.362.g079036d154-goog