Commit 0a1b0325 authored by Vincent Donnefort's avatar Vincent Donnefort Committed by Steven Rostedt (Google)
Browse files

tracing: selftests: Add trace remote tests 

Exercise the tracefs interface for trace remote with a set of tests to
check:

  * loading/unloading (unloading.tc)
  * reset (reset.tc)
  * size changes (buffer_size.tc)
  * consuming read (trace_pipe.tc)
  * non-consuming read (trace.tc)

Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Link: https://patch.msgid.link/20260309162516.2623589-16-vdonnefort@google.com


Reviewed-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarVincent Donnefort <vdonnefort@google.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent ea908a2b

tools/testing/selftests/ftrace/test.d/remotes/buffer_size.tc

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#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Test trace remote buffer size

# requires: remotes/test



. $TEST_DIR/remotes/functions



test_buffer_size()

{

    echo 0 > tracing_on

    assert_unloaded



    echo 4096 > buffer_size_kb

    echo 1 > tracing_on

    assert_loaded



    echo 0 > tracing_on

    echo 7 > buffer_size_kb

}



if [ -z "$SOURCE_REMOTE_TEST" ]; then

    set -e

    setup_remote_test

    test_buffer_size

fi

tools/testing/selftests/ftrace/test.d/remotes/functions

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# SPDX-License-Identifier: GPL-2.0



setup_remote()

{

	local name=$1



	[ -e $TRACING_DIR/remotes/$name/write_event ] || exit_unresolved



	cd remotes/$name/

	echo 0 > tracing_on

	clear_trace

	echo 7 > buffer_size_kb

	echo 0 > events/enable

	echo 1 > events/$name/selftest/enable

	echo 1 > tracing_on

}



setup_remote_test()

{

	[ -d $TRACING_DIR/remotes/test/ ] || modprobe remote_test || exit_unresolved



	setup_remote "test"

}



assert_loaded()

{

	grep -q "(loaded)" buffer_size_kb

}



assert_unloaded()

{

	grep -q "(unloaded)" buffer_size_kb

}



dump_trace_pipe()

{

    output=$(mktemp $TMPDIR/remote_test.XXXXXX)

    cat trace_pipe > $output &

    pid=$!

    sleep 1

    kill -1 $pid



    echo $output

}



check_trace()

{

	start_id="$1"

	end_id="$2"

	file="$3"



	# Ensure the file is not empty

	test -n "$(head $file)"



	prev_ts=0

	id=0



	# Only keep <timestamp> <id>

	tmp=$(mktemp $TMPDIR/remote_test.XXXXXX)

	sed -e 's/\[[0-9]*\]\s*\([0-9]*.[0-9]*\): [a-z]* id=\([0-9]*\)/\1 \2/' $file > $tmp



	while IFS= read -r line; do

		ts=$(echo $line | cut -d ' ' -f 1)

		id=$(echo $line | cut -d ' ' -f 2)



		test $(echo "$ts>$prev_ts" | bc) -eq 1

		test $id -eq $start_id



		prev_ts=$ts

		start_id=$((start_id + 1))

	done < $tmp



	test $id -eq $end_id

	rm $tmp

}



get_cpu_ids()

{

    sed -n 's/^processor\s*:\s*\([0-9]\+\).*/\1/p' /proc/cpuinfo

}



get_page_size() {

    sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page

}



get_selftest_event_size() {

    sed -ne 's/^.*field:.*;.*size:\([0-9][0-9]*\);.*/\1/p' events/*/selftest/format | awk '{s+=$1} END {print s}'

}

tools/testing/selftests/ftrace/test.d/remotes/reset.tc

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#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Test trace remote reset

# requires: remotes/test



. $TEST_DIR/remotes/functions



check_reset()

{

    write_event_path="write_event"

    taskset=""



    clear_trace



    # Is the buffer empty?

    output=$(dump_trace_pipe)

    test $(wc -l $output | cut -d ' ' -f1) -eq 0



    if $(echo $(pwd) | grep -q "per_cpu/cpu"); then

        write_event_path="../../write_event"

        cpu_id=$(echo $(pwd) | sed -e 's/.*per_cpu\/cpu//')

        taskset="taskset -c $cpu_id"

    fi

    rm $output



    # Can we properly write a new event?

    $taskset echo 7890 > $write_event_path

    output=$(dump_trace_pipe)

    test $(wc -l $output | cut -d ' ' -f1) -eq 1

    grep -q "id=7890" $output

    rm $output

}



test_global_interface()

{

    output=$(mktemp $TMPDIR/remote_test.XXXXXX)



    # Confidence check

    echo 123456 > write_event

    output=$(dump_trace_pipe)

    grep -q "id=123456" $output

    rm $output



    # Reset single event

    echo 1 > write_event

    check_reset



    # Reset lost events

    for i in $(seq 1 10000); do

        echo 1 > write_event

    done

    check_reset

}



test_percpu_interface()

{

    [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0



    for cpu in $(get_cpu_ids); do

        taskset -c $cpu echo 1 > write_event

    done



    check_non_empty=0

    for cpu in $(get_cpu_ids); do

        cd per_cpu/cpu$cpu/



        if [ $check_non_empty -eq 0 ]; then

            check_reset

            check_non_empty=1

        else

            # Check we have only reset 1 CPU

            output=$(dump_trace_pipe)

            test $(wc -l $output | cut -d ' ' -f1) -eq 1

            rm $output

        fi

        cd -

    done

}



test_reset()

{

    test_global_interface

    test_percpu_interface

}



if [ -z "$SOURCE_REMOTE_TEST" ]; then

    set -e

    setup_remote_test

    test_reset

fi

tools/testing/selftests/ftrace/test.d/remotes/trace.tc

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#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Test trace remote non-consuming read

# requires: remotes/test



. $TEST_DIR/remotes/functions



test_trace()

{

	echo 0 > tracing_on

    assert_unloaded



    echo 7 > buffer_size_kb

    echo 1 > tracing_on

    assert_loaded



    # Simple test: Emit few events and try to read them

    for i in $(seq 1 8); do

        echo $i > write_event

    done



    check_trace 1 8 trace



    #

    # Test interaction with consuming read

    #



    cat trace_pipe > /dev/null &

    pid=$!



    sleep 1

    kill $pid



    test $(wc -l < trace) -eq 0



    for i in $(seq 16 32); do

        echo $i > write_event

    done



    check_trace 16 32 trace



    #

    # Test interaction with reset

    #



    echo 0 > trace



    test $(wc -l < trace) -eq 0



    for i in $(seq 1 8); do

        echo $i > write_event

    done



    check_trace 1 8 trace



    #

    # Test interaction with lost events

    #



    # Ensure the writer is not on the reader page by reloading the buffer

    echo 0 > tracing_on

    echo 0 > trace

    assert_unloaded

    echo 1 > tracing_on

    assert_loaded



    # Ensure ring-buffer overflow by emitting events from the same CPU

    for cpu in $(get_cpu_ids); do

        break

    done



    events_per_page=$(($(get_page_size) / $(get_selftest_event_size))) # Approx: does not take TS into account

    nr_events=$(($events_per_page * 2))

    for i in $(seq 1 $nr_events); do

        taskset -c $cpu echo $i > write_event

    done



    id=$(sed -n -e '1s/\[[0-9]*\]\s*[0-9]*.[0-9]*: [a-z]* id=\([0-9]*\)/\1/p' trace)

    test $id -ne 1



    check_trace $id $nr_events trace



    #

    # Test per-CPU interface

    #

    echo 0 > trace



    for cpu in $(get_cpu_ids) ; do

        taskset -c $cpu echo $cpu > write_event

    done



    for cpu in $(get_cpu_ids); do

        cd per_cpu/cpu$cpu/



        check_trace $cpu $cpu trace



        cd - > /dev/null

    done



    #

    # Test with hotplug

    #



    [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0



    echo 0 > trace



    for cpu in $(get_cpu_ids); do

        echo 0 > /sys/devices/system/cpu/cpu$cpu/online || return 0

        break

    done



    for i in $(seq 1 8); do

        echo $i > write_event

    done



    check_trace 1 8 trace



    echo 1 > /sys/devices/system/cpu/cpu$cpu/online

}



if [ -z "$SOURCE_REMOTE_TEST" ]; then

    set -e



    setup_remote_test

    test_trace

fi

tools/testing/selftests/ftrace/test.d/remotes/trace_pipe.tc

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#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

# description: Test trace remote consuming read

# requires: remotes/test



. $TEST_DIR/remotes/functions



test_trace_pipe()

{

    echo 0 > tracing_on

    assert_unloaded



    # Emit events from the same CPU

    for cpu in $(get_cpu_ids); do

        break

    done



    #

    # Simple test: Emit enough events to fill few pages

    #



    echo 1024 > buffer_size_kb

    echo 1 > tracing_on

    assert_loaded



    events_per_page=$(($(get_page_size) / $(get_selftest_event_size)))

    nr_events=$(($events_per_page * 4))



    output=$(mktemp $TMPDIR/remote_test.XXXXXX)



    cat trace_pipe > $output &

    pid=$!



    for i in $(seq 1 $nr_events); do

        taskset -c $cpu echo $i > write_event

    done



    echo 0 > tracing_on

    sleep 1

    kill $pid



    check_trace 1 $nr_events $output



    rm $output



    #

    # Test interaction with lost events

    #



    assert_unloaded

    echo 7 > buffer_size_kb

    echo 1 > tracing_on

    assert_loaded



    nr_events=$((events_per_page * 2))

    for i in $(seq 1 $nr_events); do

        taskset -c $cpu echo $i > write_event

    done



    output=$(dump_trace_pipe)



    lost_events=$(sed -n -e '1s/CPU:.*\[LOST \([0-9]*\) EVENTS\]/\1/p' $output)

    test -n "$lost_events"



    id=$(sed -n -e '2s/\[[0-9]*\]\s*[0-9]*.[0-9]*: [a-z]* id=\([0-9]*\)/\1/p' $output)

    test "$id" -eq $(($lost_events + 1))



    # Drop [LOST EVENTS] line

    sed -i '1d' $output



    check_trace $id $nr_events $output



    rm $output



    #

    # Test per-CPU interface

    #



    echo 0 > trace

    echo 1 > tracing_on



    for cpu in $(get_cpu_ids); do

        taskset -c $cpu echo $cpu > write_event

    done



    for cpu in $(get_cpu_ids); do

        cd per_cpu/cpu$cpu/

        output=$(dump_trace_pipe)



        check_trace $cpu $cpu $output



        rm $output

        cd - > /dev/null

    done



    #

    # Test interaction with hotplug

    #



    [ "$(get_cpu_ids | wc -l)" -ge 2 ] || return 0



    echo 0 > trace



    for cpu in $(get_cpu_ids); do

        echo 0 > /sys/devices/system/cpu/cpu$cpu/online || return 0

        break

    done



    for i in $(seq 1 8); do

        echo $i > write_event

    done



    output=$(dump_trace_pipe)



    check_trace 1 8 $output



    rm $output



    echo 1 > /sys/devices/system/cpu/cpu$cpu/online

}



if [ -z "$SOURCE_REMOTE_TEST" ]; then

    set -e



    setup_remote_test

    test_trace_pipe

fi