Re: [PATCH 2/3] PERF(kernel): Cleanup power events
From: Jean Pihet
Date: Fri Nov 12 2010 - 09:20:58 EST
Thomas,
Thanks for the patches re-spin!
Here are my comments inlined.
On Thu, Nov 11, 2010 at 7:03 PM, Thomas Renninger <trenn@xxxxxxx> wrote:
> Recent changes:
> - Enable EVENT_POWER_TRACING_DEPRECATED by default
>
> New power trace events:
> power:cpu_idle
> power:cpu_frequency
> power:machine_suspend
>
>
> C-state/idle accounting events:
> power:power_start
> power:power_end
> are replaced with:
> power:cpu_idle
>
> and
> power:power_frequency
> is replaced with:
> power:cpu_frequency
>
> power:machine_suspend
> is newly introduced.
> Jean Pihet has a patch integrated into the generic layer
> (kernel/power/suspend.c) which will make use of it.
>
> the type= field got removed from both, it was never
> used and the type is differed by the event type itself.
>
> perf timechart
> userspace tool gets adjusted in a separate patch.
>
> Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
> Acked-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> Acked-by: Jean Pihet <jean.pihet@xxxxxxxxxxxxxx>
> CC: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxx>
> CC: rjw@xxxxxxx
> CC: linux-kernel@xxxxxxxxxxxxxxx
> ---
> arch/x86/kernel/process.c | 7 +++-
> arch/x86/kernel/process_32.c | 2 +-
> arch/x86/kernel/process_64.c | 2 +
> drivers/cpufreq/cpufreq.c | 1 +
> drivers/cpuidle/cpuidle.c | 1 +
> drivers/idle/intel_idle.c | 1 +
> include/trace/events/power.h | 87 +++++++++++++++++++++++++++++++++++++++++-
> kernel/trace/Kconfig | 15 +++++++
> kernel/trace/power-traces.c | 3 +
> 9 files changed, 116 insertions(+), 3 deletions(-)
>
...
> diff --git a/include/trace/events/power.h b/include/trace/events/power.h
> index 286784d..ab26d8e 100644
> --- a/include/trace/events/power.h
> +++ b/include/trace/events/power.h
> @@ -7,6 +7,67 @@
> #include <linux/ktime.h>
> #include <linux/tracepoint.h>
>
> +DECLARE_EVENT_CLASS(cpu,
> +
> + TP_PROTO(unsigned int state, unsigned int cpu_id),
> +
> + TP_ARGS(state, cpu_id),
> +
> + TP_STRUCT__entry(
> + __field( u32, state )
> + __field( u32, cpu_id )
> + ),
> +
> + TP_fast_assign(
> + __entry->state = state;
> + __entry->cpu_id = cpu_id;
> + ),
> +
> + TP_printk("state=%lu cpu_id=%lu", (unsigned long)__entry->state,
> + (unsigned long)__entry->cpu_id)
Using %lu for the state field causes PWR_EVENT_EXIT to appear as
4294967295 instead of -1. Can the field be of a signed type?
> +);
> +
> +DEFINE_EVENT(cpu, cpu_idle,
> +
> + TP_PROTO(unsigned int state, unsigned int cpu_id),
> +
> + TP_ARGS(state, cpu_id)
> +);
> +
> +/* This file can get included multiple times, TRACE_HEADER_MULTI_READ at top */
> +#ifndef _PWR_EVENT_AVOID_DOUBLE_DEFINING
> +#define _PWR_EVENT_AVOID_DOUBLE_DEFINING
> +
> +#define PWR_EVENT_EXIT -1
> +
> +#endif
> +
> +DEFINE_EVENT(cpu, cpu_frequency,
> +
> + TP_PROTO(unsigned int frequency, unsigned int cpu_id),
> +
> + TP_ARGS(frequency, cpu_id)
> +);
> +
> +TRACE_EVENT(machine_suspend,
> +
> + TP_PROTO(unsigned int state),
> +
> + TP_ARGS(state),
> +
> + TP_STRUCT__entry(
> + __field( u32, state )
> + ),
> +
> + TP_fast_assign(
> + __entry->state = state;
> + ),
> +
> + TP_printk("state=%lu", (unsigned long)__entry->state)
Same remark about the unsigned type for the state field.
> +);
> +
> +#ifdef CONFIG_EVENT_POWER_TRACING_DEPRECATED
> +
> #ifndef _TRACE_POWER_ENUM_
> #define _TRACE_POWER_ENUM_
> enum {
> @@ -153,8 +214,32 @@ DEFINE_EVENT(power_domain, power_domain_target,
>
> TP_ARGS(name, state, cpu_id)
> );
> -
> +#endif /* CONFIG_EVENT_POWER_TRACING_DEPRECATED */
The clock and power_domain events have been recently introduced and so
must be part of the new API. Can this #endif be moved right after the
definition of power_end?
> #endif /* _TRACE_POWER_H */
Should this be at the very end of the file?
>
> +/* Deprecated dummy functions must be protected against multi-declartion */
> +#ifndef EVENT_POWER_TRACING_DEPRECATED_PART_H
> +#define EVENT_POWER_TRACING_DEPRECATED_PART_H
> +
> +#ifndef CONFIG_EVENT_POWER_TRACING_DEPRECATED
> +
> +#ifndef _TRACE_POWER_ENUM_
> +#define _TRACE_POWER_ENUM_
> +enum {
> + POWER_NONE = 0,
> + POWER_CSTATE = 1,
> + POWER_PSTATE = 2,
> +};
> +#endif
> +
> +static inline void trace_power_start(u64 type, u64 state, u64 cpuid) {};
> +static inline void trace_power_end(u64 cpuid) {};
> +static inline void trace_power_frequency(u64 type, u64 state, u64 cpuid) {};
> +#endif /* CONFIG_EVENT_POWER_TRACING_DEPRECATED */
> +
> +#endif /* EVENT_POWER_TRACING_DEPRECATED_PART_H */
> +
> +
> +
> /* This part must be outside protection */
> #include <trace/define_trace.h>
> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
> index e04b8bc..0be2e7f 100644
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -69,6 +69,21 @@ config EVENT_TRACING
> select CONTEXT_SWITCH_TRACER
> bool
>
> +config EVENT_POWER_TRACING_DEPRECATED
> + depends on EVENT_TRACING
> + bool
A string is needed here. Without it it is impossible to have the option unset.
This does the trick: +bool "Deprecated power event trace API, to be removed"
> + default y
> + help
> + Provides old power event types:
> + C-state/idle accounting events:
> + power:power_start
> + power:power_end
> + and old cpufreq accounting event:
> + power:power_frequency
> + This is for userspace compatibility
> + and will vanish after 5 kernel iterations,
> + namely 2.6.41.
> +
> config CONTEXT_SWITCH_TRACER
> bool
>
...
Thanks,
Jean
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