From: "Joel Fernandes (Google)" joel@joelfernandes.org
Here we add unit tests for the preemptoff and irqsoff tracer by using a kernel module introduced previously to trigger long preempt or irq disabled sections in the kernel.
Reviewed-by: Masami Hiramatsu mhiramat@kernel.org Acked-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Joel Fernandes (Google) joel@joelfernandes.org --- 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..07db5ab09cc7 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_PREEMPTIRQ_DELAY_TEST=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..cbd174334a48 --- /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=preemptirq_delay_test + +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 test_mode=preempt delay=500000 || fail +rmmod $MOD || fail +modprobe $MOD test_mode=preempt delay=500000 || fail +rmmod $MOD || fail +modprobe $MOD test_mode=preempt delay=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 test_mode=irq delay=500000 || fail +rmmod $MOD || fail +modprobe $MOD test_mode=irq delay=500000 || fail +rmmod $MOD || fail +modprobe $MOD test_mode=irq delay=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