Re: [PATCH 2/2] kunit: tool: add --kconfig_add to allow easily tweaking kunitconfigs

[Daniel Latypov <dlatypov@google.com>]

On Mon, Nov 8, 2021 at 9:23 AM Daniel Latypov <dlatypov@google.com> wrote:
>
> On Fri, Nov 5, 2021 at 9:07 PM David Gow <davidgow@google.com> wrote:
> >
> > On Sat, Nov 6, 2021 at 9:31 AM 'Daniel Latypov' via KUnit Development
> > <kunit-dev@googlegroups.com> wrote:
> > >
> > > E.g. run tests but with KASAN
> > > $ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y
> >
> > This is very neat, thank you. I'm definitely going to use this quite a bit.
> >
> > My only real note is that we'll need to add some documentation (but
> > since the KUnit documentation is being reworked at the moment, I'm
> > okay with doing that later to avoid merge conflicts).
>
> Yeah, there's that and I was also unsure where exactly to mention it.
> I'd also want there to be the caveat about how removing the option
> won't trigger a rebuild.
> The part where we have that right now is really early on and doesn't
> need more stuff added there:
> https://www.kernel.org/doc/html/latest/dev-tools/kunit/start.html#creating-a-kunitconfig
>
> >
> > > This also works with --kunitconfig
> > > $ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kunitconfig=fs/ext4 --kconfig_add=CONFIG_KASAN=y
> >
> > It's also worth noting that this can be appended multiple times to set
> > multiple options, which is useful
>
> Ah yeah, this could be called out in the commit desc if we want a v2.
> Checking the examples in the link down below, TuxMake doesn't actually
> include one with it being repeated.
> I had been banking on readers of this message assuming that it could
> be repeated either from previous familiarity with TuxMake or by
> clicking that link.
>
> But for tweaks that require multiple options, I'm personally going to
> stick with --kunitconfig and heredocs.
> E.g. coverage requires appending 3 kconfigs, so I'm sticking with
>
> ./tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6
> --kunitconfig /dev/stdin <<EOF
> CONFIG_KUNIT=y
> CONFIG_KUNIT_ALL_TESTS=y
> CONFIG_DEBUG_KERNEL=y
> CONFIG_DEBUG_INFO=y
> CONFIG_GCOV=y
> EOF
>
> >
> > > This flag is inspired by TuxMake's --kconfig-add, see
> > > https://gitlab.com/Linaro/tuxmake#examples.
> > >
> > > Our version just uses "_" as the delimiter for consistency with
> > > pre-existing flags like --build_dir, --make_options, --kernel_args, etc.
> > >
> > > Note: this does make it easier to run into a pre-existing edge case:
> > > $ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y
> > > $ ./tools/testing/kunit/kunit.py run --arch=x86_64
> > > This second invocation ^ still has KASAN enabled!
> >
> > This behaviour is quite useful, and actually means we can turn on
> > individual items with
> > $ ./tools/testing/kunit/kunit.py config --kconfig_add=<option>
>
> Yes, that also works.
> I didn't really want to call that out, however.
>
> I ultimately would like this option to make it easier to have kunit
> commands be more declarative and less dependent on state.

I've just proposed
https://lore.kernel.org/linux-kselftest/20211118190329.1925388-1-dlatypov@google.com

If that patch goes in, the use case described above *won't* work.
I've been annoyed by the issue that removing lines from .kunitconfig
doesn't do anything for a while.

I really don't like the "stickiness" of options, since I think it's
very much not what a user would initially expect. It can be useful in
some situations, but I don't think it's worth the cost.

And I think the stickiness can be annoying to power users as well.
Imagine you were trying to debug an issue that only showed up if some
other Kconfig's are set.
Now instead of iterating by adding diff --kconfig_add=<...>, you have
to remember to delete .kunit/.config each time, lest you forget and go
down a rabbit hole.

>
> E.g. instead of
> $ cp fs/ext4/.kunitconfig .kunit/.kunitconfig
> $ echo "CONFIG_KASAN=y" >> .kunit/.kunitconfig
> $ ./tools/testing/kunit/kunit.py run --arch=x86_64
>
> it's now just one line and I'm less likely to miss a step, etc.
> $ ./tools/testing/kunit/kunit.py run --arch=x86_64
> --kunitconfig=fs/ext4 --kconfig_add=CONFIG_KASAN=y
>
> A user could alternatively do this via
> $ ./tools/testing/kunit/kunit.py config --arch=x86_64
> --kunitconfig=fs/ext4 --kconfig_add=CONFIG_KASAN=y
> $ ./tools/testing/kunit/kunit.py config --arch=x86_64
> --kconfig_add=CONFIG_ANOTHER_OPTION=y
> $ ./tools/testing/kunit/kunit.py build
> $ ./tools/testing/kunit/kunit.py exec --arch=x86_64
>
>
> >
> > > kunit.py won't call olddefconfig if our current .config is already a
> > > superset of the provided kunitconfig.
> > >
> > > Signed-off-by: Daniel Latypov <dlatypov@google.com>
> >
> > Looks good.
> >
> > Reviewed-by: David Gow <davidgow@google.com>
> >
> >
> > > ---
> > >  tools/testing/kunit/kunit.py           |  8 ++++++++
> > >  tools/testing/kunit/kunit_kernel.py    |  5 +++++
> > >  tools/testing/kunit/kunit_tool_test.py | 18 ++++++++++++++++++
> > >  3 files changed, 31 insertions(+)
> > >
> > > diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
> > > index 68e6f461c758..be58f4c93806 100755
> > > --- a/tools/testing/kunit/kunit.py
> > > +++ b/tools/testing/kunit/kunit.py
> > > @@ -280,6 +280,10 @@ def add_common_opts(parser) -> None:
> > >                              ' If given a directory, (e.g. lib/kunit), "/.kunitconfig" '
> > >                              'will get  automatically appended.',
> > >                              metavar='kunitconfig')
> > > +       parser.add_argument('--kconfig_add',
> > > +                            help='Additional Kconfig options to append to the '
> > > +                            '.kunitconfig, e.g. CONFIG_KASAN=y. Can be repeated.',
> > > +                           action='append')
> > >
> > >         parser.add_argument('--arch',
> > >                             help=('Specifies the architecture to run tests under. '
> > > @@ -398,6 +402,7 @@ def main(argv, linux=None):
> > >                 if not linux:
> > >                         linux = kunit_kernel.LinuxSourceTree(cli_args.build_dir,
> > >                                         kunitconfig_path=cli_args.kunitconfig,
> > > +                                       kconfig_add=cli_args.kconfig_add,
> > >                                         arch=cli_args.arch,
> > >                                         cross_compile=cli_args.cross_compile,
> > >                                         qemu_config_path=cli_args.qemu_config)
> > > @@ -423,6 +428,7 @@ def main(argv, linux=None):
> > >                 if not linux:
> > >                         linux = kunit_kernel.LinuxSourceTree(cli_args.build_dir,
> > >                                         kunitconfig_path=cli_args.kunitconfig,
> > > +                                       kconfig_add=cli_args.kconfig_add,
> > >                                         arch=cli_args.arch,
> > >                                         cross_compile=cli_args.cross_compile,
> > >                                         qemu_config_path=cli_args.qemu_config)
> > > @@ -439,6 +445,7 @@ def main(argv, linux=None):
> > >                 if not linux:
> > >                         linux = kunit_kernel.LinuxSourceTree(cli_args.build_dir,
> > >                                         kunitconfig_path=cli_args.kunitconfig,
> > > +                                       kconfig_add=cli_args.kconfig_add,
> > >                                         arch=cli_args.arch,
> > >                                         cross_compile=cli_args.cross_compile,
> > >                                         qemu_config_path=cli_args.qemu_config)
> > > @@ -457,6 +464,7 @@ def main(argv, linux=None):
> > >                 if not linux:
> > >                         linux = kunit_kernel.LinuxSourceTree(cli_args.build_dir,
> > >                                         kunitconfig_path=cli_args.kunitconfig,
> > > +                                       kconfig_add=cli_args.kconfig_add,
> > >                                         arch=cli_args.arch,
> > >                                         cross_compile=cli_args.cross_compile,
> > >                                         qemu_config_path=cli_args.qemu_config)
> > > diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
> > > index 51ee6e5dae91..7d459d6d6ff2 100644
> > > --- a/tools/testing/kunit/kunit_kernel.py
> > > +++ b/tools/testing/kunit/kunit_kernel.py
> > > @@ -224,6 +224,7 @@ class LinuxSourceTree(object):
> > >               build_dir: str,
> > >               load_config=True,
> > >               kunitconfig_path='',
> > > +             kconfig_add: Optional[List[str]]=None,
> > >               arch=None,
> > >               cross_compile=None,
> > >               qemu_config_path=None) -> None:
> > > @@ -249,6 +250,10 @@ class LinuxSourceTree(object):
> > >                                 shutil.copyfile(DEFAULT_KUNITCONFIG_PATH, kunitconfig_path)
> > >
> > >                 self._kconfig = kunit_config.parse_file(kunitconfig_path)
> > > +               if kconfig_add:
> > > +                       kconfig = kunit_config.parse_from_string('\n'.join(kconfig_add))
> > > +                       self._kconfig.merge_in_entries(kconfig)
> > > +
> > >
> > >         def clean(self) -> bool:
> > >                 try:
> > > diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
> > > index 4ec70e41ec5a..7e42a7c27987 100755
> > > --- a/tools/testing/kunit/kunit_tool_test.py
> > > +++ b/tools/testing/kunit/kunit_tool_test.py
> > > @@ -334,6 +334,10 @@ class LinuxSourceTreeTest(unittest.TestCase):
> > >                                 pass
> > >                         kunit_kernel.LinuxSourceTree('', kunitconfig_path=dir)
> > >
> > > +       def test_kconfig_add(self):
> > > +               tree = kunit_kernel.LinuxSourceTree('', kconfig_add=['CONFIG_NOT_REAL=y'])
> > > +               self.assertIn(kunit_config.KconfigEntry('NOT_REAL', 'y'), tree._kconfig.entries())
> > > +
> > >         def test_invalid_arch(self):
> > >                 with self.assertRaisesRegex(kunit_kernel.ConfigError, 'not a valid arch, options are.*x86_64'):
> > >                         kunit_kernel.LinuxSourceTree('', arch='invalid')
> > > @@ -540,6 +544,7 @@ class KUnitMainTest(unittest.TestCase):
> > >                 # Just verify that we parsed and initialized it correctly here.
> > >                 mock_linux_init.assert_called_once_with('.kunit',
> > >                                                         kunitconfig_path='mykunitconfig',
> > > +                                                       kconfig_add=None,
> > >                                                         arch='um',
> > >                                                         cross_compile=None,
> > >                                                         qemu_config_path=None)
> > > @@ -551,6 +556,19 @@ class KUnitMainTest(unittest.TestCase):
> > >                 # Just verify that we parsed and initialized it correctly here.
> > >                 mock_linux_init.assert_called_once_with('.kunit',
> > >                                                         kunitconfig_path='mykunitconfig',
> > > +                                                       kconfig_add=None,
> > > +                                                       arch='um',
> > > +                                                       cross_compile=None,
> > > +                                                       qemu_config_path=None)
> > > +
> > > +       @mock.patch.object(kunit_kernel, 'LinuxSourceTree')
> > > +       def test_run_kconfig_add(self, mock_linux_init):
> > > +               mock_linux_init.return_value = self.linux_source_mock
> > > +               kunit.main(['run', '--kconfig_add=CONFIG_KASAN=y', '--kconfig_add=CONFIG_KCSAN=y'])
> > > +               # Just verify that we parsed and initialized it correctly here.
> > > +               mock_linux_init.assert_called_once_with('.kunit',
> > > +                                                       kunitconfig_path=None,
> > > +                                                       kconfig_add=['CONFIG_KASAN=y', 'CONFIG_KCSAN=y'],
> > >                                                         arch='um',
> > >                                                         cross_compile=None,
> > >                                                         qemu_config_path=None)
> > > --
> > > 2.34.0.rc0.344.g81b53c2807-goog
> > >
> > > --
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