Re: [PATCH] tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"

From: Steven Rostedt
Date: Mon Aug 06 2018 - 22:00:47 EST


On Mon, 6 Aug 2018 21:54:32 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> --- a/kernel/trace/trace_preemptirq.c
> +++ b/kernel/trace/trace_preemptirq.c
> @@ -20,40 +20,52 @@ static DEFINE_PER_CPU(int, tracing_irq_cpu);
> void trace_hardirqs_on(void)
> {
> if (!this_cpu_read(tracing_irq_cpu))
> - return;
> + goto out;
>
> trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
> this_cpu_write(tracing_irq_cpu, 0);
> +
> + out:
> + lockdep_hardirqs_on(CALLER_ADDR0);
> }
> EXPORT_SYMBOL(trace_hardirqs_on);
>
> void trace_hardirqs_off(void)
> {
> if (this_cpu_read(tracing_irq_cpu))
> - return;
> + goto out;
>
> this_cpu_write(tracing_irq_cpu, 1);
> trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
> +
> + out:
> + lockdep_hardirqs_off(CALLER_ADDR0);
> }
> EXPORT_SYMBOL(trace_hardirqs_off);
>
> __visible void trace_hardirqs_on_caller(unsigned long caller_addr)
> {
> if (!this_cpu_read(tracing_irq_cpu))
> - return;
> + goto out;
>
> trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
> this_cpu_write(tracing_irq_cpu, 0);
> +
> + out:
> + lockdep_hardirqs_on(CALLER_ADDR0);
> }
> EXPORT_SYMBOL(trace_hardirqs_on_caller);
>
> __visible void trace_hardirqs_off_caller(unsigned long caller_addr)
> {
> if (this_cpu_read(tracing_irq_cpu))
> - return;
> + goto out;
>
> this_cpu_write(tracing_irq_cpu, 1);
> trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
> +
> + out:
> + lockdep_hardirqs_off(CALLER_ADDR0);
> }
> EXPORT_SYMBOL(trace_hardirqs_off_caller);
> #endif /* CONFIG_TRACE_IRQFLAGS */

Hmm, the gotos above are rather ugly. This look better?

-- Steve


diff --git a/kernel/trace/trace_preemptirq.c b/kernel/trace/trace_preemptirq.c
index e76b78bf258e..fa656b25f427 100644
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -19,41 +19,45 @@ static DEFINE_PER_CPU(int, tracing_irq_cpu);

void trace_hardirqs_on(void)
{
- if (!this_cpu_read(tracing_irq_cpu))
- return;
+ if (this_cpu_read(tracing_irq_cpu)) {
+ trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
+ this_cpu_write(tracing_irq_cpu, 0);
+ }

- trace_irq_enable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
- this_cpu_write(tracing_irq_cpu, 0);
+ lockdep_hardirqs_on(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_on);

void trace_hardirqs_off(void)
{
- if (this_cpu_read(tracing_irq_cpu))
- return;
+ if (!this_cpu_read(tracing_irq_cpu)) {
+ this_cpu_write(tracing_irq_cpu, 1);
+ trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
+ }

- this_cpu_write(tracing_irq_cpu, 1);
- trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
+ lockdep_hardirqs_off(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_off);

__visible void trace_hardirqs_on_caller(unsigned long caller_addr)
{
- if (!this_cpu_read(tracing_irq_cpu))
- return;
+ if (this_cpu_read(tracing_irq_cpu)) {
+ trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
+ this_cpu_write(tracing_irq_cpu, 0);
+ }

- trace_irq_enable_rcuidle(CALLER_ADDR0, caller_addr);
- this_cpu_write(tracing_irq_cpu, 0);
+ lockdep_hardirqs_on(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_on_caller);

__visible void trace_hardirqs_off_caller(unsigned long caller_addr)
{
- if (this_cpu_read(tracing_irq_cpu))
- return;
+ if (!this_cpu_read(tracing_irq_cpu)) {
+ this_cpu_write(tracing_irq_cpu, 1);
+ trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
+ }

- this_cpu_write(tracing_irq_cpu, 1);
- trace_irq_disable_rcuidle(CALLER_ADDR0, caller_addr);
+ lockdep_hardirqs_off(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_off_caller);
#endif /* CONFIG_TRACE_IRQFLAGS */