tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ringbuffer/selftest: Add basic selftest to test changing subbuf order
Add a self test that will write into the trace buffer with differ trace
sub buffer order sizes.
Link: https://lore.kernel.org/linux-trace-kernel/20231219185631.520496304@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
+95
+95
tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
+95
tools/testing/selftests/ftrace/test.d/00basic/ringbuffer_order.tc
···
1
+
#!/bin/sh
2
+
# SPDX-License-Identifier: GPL-2.0
3
+
# description: Change the ringbuffer sub-buffer order
4
+
# requires: buffer_subbuf_order
5
+
# flags: instance
6
+
7
+
get_buffer_data_size() {
8
+
sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page
9
+
}
10
+
11
+
get_buffer_data_offset() {
12
+
sed -ne 's/^.*data.*offset:\([0-9][0-9]*\).*/\1/p' events/header_page
13
+
}
14
+
15
+
get_event_header_size() {
16
+
type_len=`sed -ne 's/^.*type_len.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event`
17
+
time_len=`sed -ne 's/^.*time_delta.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event`
18
+
array_len=`sed -ne 's/^.*array.*:[^0-9]*\([0-9][0-9]*\).*/\1/p' events/header_event`
19
+
total_bits=$((type_len+time_len+array_len))
20
+
total_bits=$((total_bits+7))
21
+
echo $((total_bits/8))
22
+
}
23
+
24
+
get_print_event_buf_offset() {
25
+
sed -ne 's/^.*buf.*offset:\([0-9][0-9]*\).*/\1/p' events/ftrace/print/format
26
+
}
27
+
28
+
event_header_size=`get_event_header_size`
29
+
print_header_size=`get_print_event_buf_offset`
30
+
31
+
data_offset=`get_buffer_data_offset`
32
+
33
+
marker_meta=$((event_header_size+print_header_size))
34
+
35
+
make_str() {
36
+
cnt=$1
37
+
printf -- 'X%.0s' $(seq $cnt)
38
+
}
39
+
40
+
write_buffer() {
41
+
size=$1
42
+
43
+
str=`make_str $size`
44
+
45
+
# clear the buffer
46
+
echo > trace
47
+
48
+
# write the string into the marker
49
+
echo $str > trace_marker
50
+
51
+
echo $str
52
+
}
53
+
54
+
test_buffer() {
55
+
orde=$1
56
+
page_size=$((4096<<order))
57
+
58
+
size=`get_buffer_data_size`
59
+
60
+
# the size must be greater than or equal to page_size - data_offset
61
+
page_size=$((page_size-data_offset))
62
+
if [ $size -lt $page_size ]; then
63
+
exit fail
64
+
fi
65
+
66
+
# Now add a little more the meta data overhead will overflow
67
+
68
+
str=`write_buffer $size`
69
+
70
+
# Make sure the line was broken
71
+
new_str=`awk ' /tracing_mark_write:/ { sub(/^.*tracing_mark_write: /,"");printf "%s", $0; exit}' trace`
72
+
73
+
if [ "$new_str" = "$str" ]; then
74
+
exit fail;
75
+
fi
76
+
77
+
# Make sure the entire line can be found
78
+
new_str=`awk ' /tracing_mark_write:/ { sub(/^.*tracing_mark_write: /,"");printf "%s", $0; }' trace`
79
+
80
+
if [ "$new_str" != "$str" ]; then
81
+
exit fail;
82
+
fi
83
+
}
84
+
85
+
ORIG=`cat buffer_subbuf_order`
86
+
87
+
# Could test bigger orders than 3, but then creating the string
88
+
# to write into the ring buffer takes too long
89
+
for a in 0 1 2 3 ; do
90
+
echo $a > buffer_subbuf_order
91
+
test_buffer $a
92
+
done
93
+
94
+
echo $ORIG > buffer_subbuf_order
95
+