Re: [PATCH v8 1/2] tracing: Prepare to add preempt and irq trace events

[Steven Rostedt]

On Thu,  5 Oct 2017 17:54:31 -0700
Joel Fernandes <joelaf@xxxxxxxxxx> wrote:

> In preparation of adding irqsoff and preemptsoff enable and disable trace
> events, move required functions and code to make it easier to add these events
> in a later patch. This patch is just code movement and no functional change.

New warning:

 kernel/trace/trace_irqsoff.c:783:69: warning: 'tracing_irq_cpu' defined but not used [-Wunused-variable]

Looks pretty obvious what the fix is. Care to send a v9?

-- Steve

> 
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: kernel-team@xxxxxxxxxxx
> Signed-off-by: Joel Fernandes <joelaf@xxxxxxxxxx>
> ---
>  kernel/trace/trace_irqsoff.c | 100 ++++++++++++++++++++++++++++++++-----------
>  1 file changed, 74 insertions(+), 26 deletions(-)
> 
> diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
> index 7758bc0617cb..0e3033c00474 100644
> --- a/kernel/trace/trace_irqsoff.c
> +++ b/kernel/trace/trace_irqsoff.c
> @@ -16,6 +16,7 @@
>  
>  #include "trace.h"
>  
> +#if defined(CONFIG_IRQSOFF_TRACER) || defined(CONFIG_PREEMPT_TRACER)
>  static struct trace_array		*irqsoff_trace __read_mostly;
>  static int				tracer_enabled __read_mostly;
>  
> @@ -462,64 +463,44 @@ void time_hardirqs_off(unsigned long a0, unsigned long a1)
>  
>  #else /* !CONFIG_PROVE_LOCKING */
>  
> -/*
> - * Stubs:
> - */
> -
> -void trace_softirqs_on(unsigned long ip)
> -{
> -}
> -
> -void trace_softirqs_off(unsigned long ip)
> -{
> -}
> -
> -inline void print_irqtrace_events(struct task_struct *curr)
> -{
> -}
> -
>  /*
>   * We are only interested in hardirq on/off events:
>   */
> -void trace_hardirqs_on(void)
> +static inline void tracer_hardirqs_on(void)
>  {
>  	if (!preempt_trace() && irq_trace())
>  		stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
>  }
> -EXPORT_SYMBOL(trace_hardirqs_on);
>  
> -void trace_hardirqs_off(void)
> +static inline void tracer_hardirqs_off(void)
>  {
>  	if (!preempt_trace() && irq_trace())
>  		start_critical_timing(CALLER_ADDR0, CALLER_ADDR1);
>  }
> -EXPORT_SYMBOL(trace_hardirqs_off);
>  
> -__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
> +static inline void tracer_hardirqs_on_caller(unsigned long caller_addr)
>  {
>  	if (!preempt_trace() && irq_trace())
>  		stop_critical_timing(CALLER_ADDR0, caller_addr);
>  }
> -EXPORT_SYMBOL(trace_hardirqs_on_caller);
>  
> -__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
> +static inline void tracer_hardirqs_off_caller(unsigned long caller_addr)
>  {
>  	if (!preempt_trace() && irq_trace())
>  		start_critical_timing(CALLER_ADDR0, caller_addr);
>  }
> -EXPORT_SYMBOL(trace_hardirqs_off_caller);
>  
>  #endif /* CONFIG_PROVE_LOCKING */
>  #endif /*  CONFIG_IRQSOFF_TRACER */
>  
>  #ifdef CONFIG_PREEMPT_TRACER
> -void trace_preempt_on(unsigned long a0, unsigned long a1)
> +static inline void tracer_preempt_on(unsigned long a0, unsigned long a1)
>  {
>  	if (preempt_trace() && !irq_trace())
>  		stop_critical_timing(a0, a1);
>  }
>  
> -void trace_preempt_off(unsigned long a0, unsigned long a1)
> +static inline void tracer_preempt_off(unsigned long a0, unsigned long a1)
>  {
>  	if (preempt_trace() && !irq_trace())
>  		start_critical_timing(a0, a1);
> @@ -781,3 +762,70 @@ __init static int init_irqsoff_tracer(void)
>  	return 0;
>  }
>  core_initcall(init_irqsoff_tracer);
> +#endif /* IRQSOFF_TRACER || PREEMPTOFF_TRACER */
> +
> +#ifndef CONFIG_IRQSOFF_TRACER
> +static inline void tracer_hardirqs_on(void) { }
> +static inline void tracer_hardirqs_off(void) { }
> +static inline void tracer_hardirqs_on_caller(unsigned long caller_addr) { }
> +static inline void tracer_hardirqs_off_caller(unsigned long caller_addr) { }
> +#endif
> +
> +#ifndef CONFIG_PREEMPT_TRACER
> +static inline void tracer_preempt_on(unsigned long a0, unsigned long a1) { }
> +static inline void tracer_preempt_off(unsigned long a0, unsigned long a1) { }
> +#endif
> +
> +#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PROVE_LOCKING)
> +void trace_hardirqs_on(void)
> +{
> +	tracer_hardirqs_on();
> +}
> +EXPORT_SYMBOL(trace_hardirqs_on);
> +
> +void trace_hardirqs_off(void)
> +{
> +	tracer_hardirqs_off();
> +}
> +EXPORT_SYMBOL(trace_hardirqs_off);
> +
> +__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
> +{
> +	tracer_hardirqs_on_caller(caller_addr);
> +}
> +EXPORT_SYMBOL(trace_hardirqs_on_caller);
> +
> +__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
> +{
> +	tracer_hardirqs_off_caller(caller_addr);
> +}
> +EXPORT_SYMBOL(trace_hardirqs_off_caller);
> +
> +/*
> + * Stubs:
> + */
> +
> +void trace_softirqs_on(unsigned long ip)
> +{
> +}
> +
> +void trace_softirqs_off(unsigned long ip)
> +{
> +}
> +
> +inline void print_irqtrace_events(struct task_struct *curr)
> +{
> +}
> +#endif
> +
> +#ifdef CONFIG_PREEMPT_TRACER
> +void trace_preempt_on(unsigned long a0, unsigned long a1)
> +{
> +	tracer_preempt_on(a0, a1);
> +}
> +
> +void trace_preempt_off(unsigned long a0, unsigned long a1)
> +{
> +	tracer_preempt_off(a0, a1);
> +}
> +#endif