On Mon, Mar 28, 2022 at 2:58 PM 'Daniel Latypov' via KUnit Development kunit-dev@googlegroups.com wrote:
On Mon, Mar 28, 2022 at 11:54 AM 'Brendan Higgins' via KUnit Development kunit-dev@googlegroups.com wrote:
On Mon, Mar 28, 2022 at 12:35 PM Daniel Latypov dlatypov@google.com wrote:
On Fri, Mar 25, 2022 at 9:56 PM David Gow davidgow@google.com wrote:
<snip>
# Append coverage options to the current config
$ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig
$ echo -e "CONFIG_DEBUG_KERNEL=y\nCONFIG_DEBUG_INFO=y\nCONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y\nCONFIG_GCOV=y" >> .kunit/.kunitconfig $ ./tools/testing/kunit/kunit.py runWould we want to instead use a chain of --kconfig_add arguments? (I think there are advantages either way...)
I've been considering this ever since the --kconfig_add patch was accepted. It's more compatible w/ commands using --kunitconfig, but it also looks very verbose. E.g. it looks like
$ tools/testing/kunit/kunit.py run --make_options=CC=/usr/bin/gcc-6 --kconfig_add=CONFIG_DEBUG_INFO=y --kconfig_add=CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y --kconfig_add=CONFIG_GCOV=y
I don't think it's *that* much more verbose, but I see your point. I personally prefer this, but not enough to argue about it.
I personally prefer it too, but I'm biased as the person who added --kconfig_add. They're both ugly enough I'd figured I'd save the bikeshedding for another patch.
Neither looks very appealing to me, so I've just kept it as-is for now.
Maybe there's something we can do to make this easier (e.g. allowing --kunitconfig to be repeated and mergable)?
I would like --kunitconfig to be repeadable and mergable.
Ack. There's some things to consider first.
I wasn't saying I want you to do it now. I just like the idea.
- This will conflict w/
https://patchwork.kernel.org/project/linux-kselftest/patch/20220226212325.29..., so I'm going to wait until that gets merged first.
Agreed.
- some kconfigs can be incompatible (e.g. these options only work on
UML, can't combine w/ a non-UML compatible file) How do we make this less of a footgun? We'd talked about how it'd be nice if kconfig/"make olddefconfig" could print out *why* options get dropped (either they're not visible, have unmet deps, etc.). If we had that, I'd feel more comfortable w/ repeatable kunitconfig.
Good point. Something to think about.
- People have the ability to do this already if they're really sure it's safe
$ cat <files...> | ./tools/testing/kunit/kunit.py run --kunitconfig=/dev/stdin
Sure, but I still think multiple --kunitconfig s would be a good feature to add. I think it makes it a bit easier to think about mixing and matching kunitconfigs.
- are we committed to supporting a "uml_coverage.kunitconfig" file?
As shown by the existence of this patch, we've let it get broken for a bit, at least against linux-next (afaik, it was working on torvalds/master up until the 5.18 window opened and we had some patches reworking CONFIG_DEBUG_INFO).
Good point. I don't think we want to get in that business. UML Coverage needs a lot of work, and I don't think we have the time or resources to own that work by ourselves.
If someone else wants to add - and then own - such a kunitconfig, I would fully support them and maybe even help them a bit, but I don't want to own such a file until UML coverage gets a bit more stable.
These instructions exist so others don't have to try and re-figure out the steps/workarounds. But they're not more formally "part of KUnit" since no one has had the expertise to maintain it (and fix issues like the reliance on gcc-6), etc.
Creating a kunitconfig file for this will further imply ownership.
Agreed.