On Tue, 19 Dec 2023 13:54:28 -0500
Steven Rostedt <rost...@goodmis.org> wrote:
> From: "Steven Rostedt (Google)" <rost...@goodmis.org>
>
> Add a self test that will write into the trace buffer with differ trace
> sub buffer order sizes.
>
> Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
> ---
> .../ftrace/test.d/00basic/ringbuffer_order.tc | 95 +++++++++++++++++++
> 1 file changed, 95 insertions(+)
> create mode 100644
> tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
>
> diff --git
> a/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
> b/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
> new file mode 100644
> index 000000000000..ecbcc810e6c1
> --- /dev/null
> +++ b/tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
> @@ -0,0 +1,95 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +# description: Change the ringbuffer sub-buffer order
> +# requires: buffer_subbuf_order
> +# 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`
> +
> +data_offset=`get_buffer_data_offset`
> +
> +marker_meta=$((event_header_size+print_header_size))
> +
> +make_str() {
> + cnt=$1
> + 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 $str > trace_marker
> +
> + echo $str
> +}
> +
> +test_buffer() {
> + orde=$1
> + page_size=$((4096<<order))
> +
> + size=`get_buffer_data_size`
> +
> + # the size must be greater than or equal to page_size - data_offset
> + page_size=$((page_size-data_offset))
> + if [ $size -lt $page_size ]; then
> + exit fail
> + fi
> +
> + # 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
> +}
> +
> +ORIG=`cat buffer_subbuf_order`
> +
> +# Could test bigger orders than 3, but then creating the string
> +# to write into the ring buffer takes too long
For testing purpose, I think it is better to check whether the maximum order
can pass or not. Or shrink down the max order to support. (I think order=3 is
enough big at this moment)
Thank you,
> +for a in 0 1 2 3 ; do
> + echo $a > buffer_subbuf_order
> + test_buffer $a
> +done
> +
> +echo $ORIG > buffer_subbuf_order
> +
> --
> 2.42.0
>
>
--
Masami Hiramatsu (Google) <mhira...@kernel.org>
