On Tue, 12 Dec 2023 15:16:32 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> > > Now that the trace_marker can write up to the max size of the sub buffer. > Add a test to see if it actually can happen. > > The README is updated to state that the trace_marker writes can be broken > up, and the test checks the README for that statement so that it does not > fail on older kernels that does not support this. I think it is better that the feature patch include README update or a separate patch because it identifies the feature is implemented or not. > > If the README does not have the specified update, the test will still test > if all the string is written, as that should work with older kernels. > > Cc: Shuah Khan <shuah@xxxxxxxxxx> > Cc: linux-kselftest@xxxxxxxxxxxxxxx > Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> > --- > Changes since v1: https://lore.kernel.org/linux-trace-kernel/20231212135441.0337c3e9@xxxxxxxxxxxxxxxxxx/ > > - Fix description as it was a cut and paste from the subbuffer size tests > that are not added yet. > > kernel/trace/trace.c | 1 + > .../ftrace/test.d/00basic/trace_marker.tc | 112 ++++++++++++++++++ > 2 files changed, 113 insertions(+) > create mode 100755 tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 2f8d59834c00..cbfcdd882590 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5595,6 +5595,7 @@ static const char readme_msg[] = > " delta: Delta difference against a buffer-wide timestamp\n" > " absolute: Absolute (standalone) timestamp\n" > "\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n" > + "\n May be broken into multiple events based on sub-buffer size.\n" > "\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n" > " tracing_cpumask\t- Limit which CPUs to trace\n" > " instances\t\t- Make sub-buffers with: mkdir instances/foo\n" > diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc > new file mode 100755 > index 000000000000..bf7f6f50c88a > --- /dev/null > +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc > @@ -0,0 +1,112 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +# description: Basic tests on writing to trace_marker > +# requires: trace_marker > +# flags: instance > + > +get_buffer_data_size() { > + sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page > +} > + > +get_buffer_data_offset() { > + sed -ne 's/^.*data.*offset:\([0-9][0-9]*\).*/\1/p' events/header_page > +} > + > +get_event_header_size() { > + type_len=`sed -ne 's/^.*type_len.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event` > + time_len=`sed -ne 's/^.*time_delta.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event` > + array_len=`sed -ne 's/^.*array.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event` > + total_bits=$((type_len+time_len+array_len)) > + total_bits=$((total_bits+7)) > + echo $((total_bits/8)) > +} > + > +get_print_event_buf_offset() { > + sed -ne 's/^.*buf.*offset:\([0-9][0-9]*\).*/\1/p' events/ftrace/print/format > +} > + > +event_header_size=`get_event_header_size` > +print_header_size=`get_print_event_buf_offset` > + > +# Find the README > +README="" > +if [ -f README ]; then > + README="README" > +# instance? > +elif [ -f ../../README ]; then > + README="../../README" > +fi > + > +testone=0 > +if [ ! -z "$README" ]; then > + if grep -q "May be broken into multiple events based on sub-buffer size" $README; then > + testone=1 > + fi > +fi Hmm, this should be a common function if we see this pattern somewhere else. > + > +data_offset=`get_buffer_data_offset` > + > +marker_meta=$((event_header_size+print_header_size)) > + > +make_str() { > + cnt=$1 > + # subtract two for \n\0 as marker adds these > + cnt=$((cnt-2)) > + printf -- 'X%.0s' $(seq $cnt) > +} > + > +write_buffer() { > + size=$1 > + > + str=`make_str $size` > + > + # clear the buffer > + echo > trace > + > + # write the string into the marker > + echo -n $str > trace_marker > + > + echo $str > +} > + > +test_buffer() { > + > + size=`get_buffer_data_size` > + oneline_size=$((size-marker_meta)) > + echo size = $size > + echo meta size = $marker_meta > + > + if [ $testone -eq 1 ]; then > + echo oneline size = $oneline_size > + > + str=`write_buffer $oneline_size` > + > + # Should be in one single event > + new_str=`awk ' /tracing_mark_write:/ { sub(/^.*tracing_mark_write: */,"");printf "%s", $0; exit}' trace` > + > + if [ "$new_str" != "$str" ]; then > + exit fail; > + fi > + fi Or, maybe we can split this part into another testcase. Thank you, > + > + # Now add a little more the meta data overhead will overflow > + > + str=`write_buffer $size` > + > + # Make sure the line was broken > + new_str=`awk ' /tracing_mark_write:/ { sub(/^.*tracing_mark_write: /,"");printf "%s", $0; exit}' trace` > + > + if [ "$new_str" = "$str" ]; then > + exit fail; > + fi > + > + # Make sure the entire line can be found > + new_str=`awk ' /tracing_mark_write:/ { sub(/^.*tracing_mark_write: */,"");printf "%s", $0; }' trace` > + > + if [ "$new_str" != "$str" ]; then > + exit fail; > + fi > +} > + > +test_buffer > + > -- > 2.42.0 > -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
