Re: [PATCH v9 7/7] kselftests: Add tests for the preemptoff and irqsoff tracers

[Steven Rostedt]

On Thu, 28 Jun 2018 11:21:49 -0700
Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:

> From: "Joel Fernandes (Google)" <joel@xxxxxxxxxxxxxxxxx>
> 
> Here we add unit tests for the preemptoff and irqsoff tracer by using a
> kernel module introduced previously to trigger atomic sections in the
> kernel.
> 
> Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>

This looks fine. The only patch that needs to be changed and resent is
patch 6 and 7. Just send 6, and this one again because it depends on
patch 6.

I'll go ahead and apply 1-5 and kick off my other tests.

Thanks!

-- Steve


> ---
>  tools/testing/selftests/ftrace/config         |  3 +
>  .../test.d/preemptirq/irqsoff_tracer.tc       | 73 +++++++++++++++++++
>  2 files changed, 76 insertions(+)
>  create mode 100644 tools/testing/selftests/ftrace/test.d/preemptirq/irqsoff_tracer.tc
> 
> diff --git a/tools/testing/selftests/ftrace/config b/tools/testing/selftests/ftrace/config
> index b01924c71c09..29588b328345 100644
> --- a/tools/testing/selftests/ftrace/config
> +++ b/tools/testing/selftests/ftrace/config
> @@ -4,3 +4,6 @@ CONFIG_FUNCTION_PROFILER=y
>  CONFIG_TRACER_SNAPSHOT=y
>  CONFIG_STACK_TRACER=y
>  CONFIG_HIST_TRIGGERS=y
> +CONFIG_PREEMPT_TRACER=y
> +CONFIG_IRQSOFF_TRACER=y
> +CONFIG_TEST_ATOMIC_SECTIONS=m
> diff --git a/tools/testing/selftests/ftrace/test.d/preemptirq/irqsoff_tracer.tc b/tools/testing/selftests/ftrace/test.d/preemptirq/irqsoff_tracer.tc
> new file mode 100644
> index 000000000000..1806d340035d
> --- /dev/null
> +++ b/tools/testing/selftests/ftrace/test.d/preemptirq/irqsoff_tracer.tc
> @@ -0,0 +1,73 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# description: test for the preemptirqsoff tracer
> +
> +MOD=test_atomic_sections
> +
> +fail() {
> +    reset_tracer
> +    rmmod $MOD || true
> +    exit_fail
> +}
> +
> +unsup() { #msg
> +    reset_tracer
> +    rmmod $MOD || true
> +    echo $1
> +    exit_unsupported
> +}
> +
> +modprobe $MOD || unsup "$MOD module not available"
> +rmmod $MOD
> +
> +grep -q "preemptoff" available_tracers || unsup "preemptoff tracer not enabled"
> +grep -q "irqsoff" available_tracers || unsup "irqsoff tracer not enabled"
> +
> +reset_tracer
> +
> +# Simulate preemptoff section for half a second couple of times
> +echo preemptoff > current_tracer
> +sleep 1
> +modprobe $MOD atomic_mode=preempt atomic_time=500000 || fail
> +rmmod $MOD || fail
> +modprobe $MOD atomic_mode=preempt atomic_time=500000 || fail
> +rmmod $MOD || fail
> +modprobe $MOD atomic_mode=preempt atomic_time=500000 || fail
> +rmmod $MOD || fail
> +
> +cat trace
> +
> +# Confirm which tracer
> +grep -q "tracer: preemptoff" trace || fail
> +
> +# Check the end of the section
> +egrep -q "5.....us : <stack trace>" trace || fail
> +
> +# Check for 500ms of latency
> +egrep -q "latency: 5..... us" trace || fail
> +
> +reset_tracer
> +
> +# Simulate irqsoff section for half a second couple of times
> +echo irqsoff > current_tracer
> +sleep 1
> +modprobe $MOD atomic_mode=irq atomic_time=500000 || fail
> +rmmod $MOD || fail
> +modprobe $MOD atomic_mode=irq atomic_time=500000 || fail
> +rmmod $MOD || fail
> +modprobe $MOD atomic_mode=irq atomic_time=500000 || fail
> +rmmod $MOD || fail
> +
> +cat trace
> +
> +# Confirm which tracer
> +grep -q "tracer: irqsoff" trace || fail
> +
> +# Check the end of the section
> +egrep -q "5.....us : <stack trace>" trace || fail
> +
> +# Check for 500ms of latency
> +egrep -q "latency: 5..... us" trace || fail
> +
> +reset_tracer
> +exit 0