kselftests: Add tests for the preemptoff and irqsoff tracers

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.

Link: http://lkml.kernel.org/r/20180711063540.91101-3-joel@joelfernandes.org

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Joel Fernandes (Google) 2018-07-10 23:35:40 -07:00 committed by Steven Rostedt (VMware)
parent f96e8577da
commit 8bd1369b4c
2 changed files with 76 additions and 0 deletions

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@ -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

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@ -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