linux.git/tools/perf/tests/shell/diff.sh, branch v6.18.21

perf test: Change all remaining #!/bin/sh to #!/bin/bash

2025-06-26T17:31:05+00:00

There are 43 instances of posix shell tests and 35 instances of bash. To
give us a single consistent language for testing in, replace
all #!/bin/sh to #!/bin/bash. Common sources that are included in both
different shells will now work as expected. And we no longer have to fix
up bashisms that appear to work when someone's system has sh symlinked
to bash, but don't work on other systems that have both shells
installed.

Although we could have chosen sh, it's not backwards compatible so it
wouldn't be possible to bulk convert without re-writing the existing
bash tests.

Choosing bash also gives us some nicer features including 'local'
variable definitions and regexes in if statements that are already
widely used in the tests.

It's not expected that there are any users with only sh available due to
the large number of bash tests that exist.

Discussed in relation to running shellcheck here:
https://lore.kernel.org/linux-perf-users/e3751a74be34bbf3781c4644f518702a7270220b.1749785642.git.collin.funk1@gmail.com/

Signed-off-by: James Clark 
Reviewed-by: Collin Funk 
Acked-by: Arnaldo Carvalho de Melo 
Link: https://lore.kernel.org/r/20250623-james-perf-bash-tests-v1-1-f572f54d4559@linaro.org
Signed-off-by: Namhyung Kim

perf test: Fixes to variable expansion and stdout for diff test

2025-03-15T01:15:13+00:00

When make_data fails its error message needs to go to stderr rather
than stdout and the stdout value is captured in a variable.  Quote the
$err value so that it is always a valid input for test.  This error is
commonly encountered if no sample data is gathered by the test.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250312001841.1515779-1-irogers@google.com
Signed-off-by: Namhyung Kim

perf test shell diff: Skip test if test_loop symbol is missing in the perf binary

2023-12-06T16:01:36+00:00

The diff test depends on finding the symbol test_loop in perf and will
fail if perf has been stripped and no debug object is available. In that
case, skip the test instead.

Suggested-by: Adrian Hunter 
Signed-off-by: Ian Rogers 
Tested-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231205164924.835682-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add basic 'perf diff' test

2023-12-05T18:48:52+00:00

There are some old bug reports on perf diff crashing:

https://rhaas.blogspot.com/2012/06/perf-good-bad-ugly.html

Happening across them I was prompted to add two very basic tests that
will give some 'perf diff' coverage.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Jajeev 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231120190408.281826-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo