Re: [PATCH v3] tracing/selftests: Add test to test the trace_marker

The REs used in the sed commands below may be simplified as shown if desired.

On Wed, Dec 13, 2023 at 2:22 AM Steven Rostedt rostedt@goodmis.org wrote:

From: "Steven Rostedt (Google)" rostedt@goodmis.org

Add a test that writes longs strings, some over the size of the sub buffer and make sure that the entire content is there.

Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org

Changes since v2: https://lore.kernel.org/linux-trace-kernel/20231212151632.25c9b67d@gandalf.l...

• Realized with the upcoming change of the dynamic subbuffer sizes, that this test will fail if the subbuffer is bigger than what the trace_seq can hold. Now the trace_marker does not always utilize the full subbuffer but the size of the trace_seq instead. As that size isn't available to user space, we can only just make sure all content is there.

.../ftrace/test.d/00basic/trace_marker.tc | 82 +++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100755 tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc

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..b24aff5807df --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker.tc @@ -0,0 +1,82 @@ +#!/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
  

sed -n 's!.*data.*size:([^;]*).*!\1!p' events/header_page

+}

+get_buffer_data_offset() {

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

sed -n 's!.*data.*offset:([^;]*).*!\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`
  

type_len=`sed -n '/type_len.*bits/s![^0-9]*!!gp' events/header_event`

•   time_len=`sed -ne 's/^.*time_delta.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event`
  

time_len=`sed -n '/time_delta/s![^0-9]*!!gp' events/header_event`

•   array_len=`sed -ne 's/^.*array.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event`
  

array_len=`sed -n '/array/s![^0-9]*!!gp' 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
  

sed -n 's!.*buf.*offset:([^;]*).*!\1!p' events/ftrace/print/format

+}

+event_header_size=`get_event_header_size` +print_header_size=`get_print_event_buf_offset`

+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
  

•   # 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