From: Fushuai Wang wangfushuai@baidu.com

When /sys/kernel/tracing/buffer_size_kb is less than 12KB, the test_multiple_writes test will stall and wait for more input due to insufficient buffer space.

Check current buffer_size_kb value before the test. If it is less than 12KB, it temporarily increase the buffer to 12KB, and restore the original value after the tests are completed.

Fixes: 37f46601383a ("selftests/tracing: Add basic test for trace_marker_raw file") Suggested-by: Steven Rostedt rostedt@goodmis.org Signed-off-by: Fushuai Wang wangfushuai@baidu.com Acked-by: Steven Rostedt (Google) rostedt@goodmis.org --- V2 -> V3: Make the From and SoB match. V1 -> V2: Restore buffer_size_kb outside of awk script.

.../ftrace/test.d/00basic/trace_marker_raw.tc | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc index 7daf7292209e..a2c42e13f614 100644 --- a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc +++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc @@ -89,6 +89,7 @@ test_buffer() { # The id must be four bytes, test that 3 bytes fails a write if echo -n abc > ./trace_marker_raw ; then echo "Too small of write expected to fail but did not" + echo ${ORIG} > buffer_size_kb exit_fail fi

@@ -99,9 +100,24 @@ test_buffer() {

if write_buffer 0xdeadbeef $size ; then echo "Too big of write expected to fail but did not" + echo ${ORIG} > buffer_size_kb exit_fail fi }

+ORIG=`cat buffer_size_kb` + +# test_multiple_writes test needs at least 12KB buffer +NEW_SIZE=12 + +if [ ${ORIG} -lt ${NEW_SIZE} ]; then + echo ${NEW_SIZE} > buffer_size_kb +fi + test_buffer -test_multiple_writes +if ! test_multiple_writes; then + echo ${ORIG} > buffer_size_kb + exit_fail +fi + +echo ${ORIG} > buffer_size_kb