On Thu, May 19, 2022 at 6:15 AM David Gow <davidgow@xxxxxxxxxx> wrote: > > I tend to agree that having both would be nice: I think there are > enough useful "machine configs" that trying to maintain, e.g, a 1:1 > mapping with kernel architectures is going to leave a bunch of things > on the table, particularly as we add more tests for, e.g., drivers and > specific CPU models. I agree that we don't necessarily need to maintain a 1:1 mapping. But I feel like we should have a pretty convincing reason for doing so, e.g. support for a CPU that requires we add in a bunch of kconfigs. This particular one feels simple enough to me. Given we already have to put specific instructions in the kcsan/.kunitconfig, I don't know if there's much of a difference in cost between these two commands $ ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan --arch=x86_64-smp $ ./tools/testing/kunit/kunit.py run --kunitconfig=kernel/kcsan --arch=x86_64 --kconfig_add CONFIG_SMP=y --qemu_args "-smp 8" I've generally learned to prefer more explicit commands like the second, even if they're quite a bit longer. But I have the following biases * I use FZF heavily, so I don't re-type long commands much * I'm the person who proposed --kconfig_add and --qemu_args, so of course I'd think the longer form is easy to understand. so I'm not in a position to object to this change. Changing topics: Users can overwrite the '-smp 8' here via --qemu_args [1], so I'm much less worried about hard-coding any specific value in this file anymore. And given that, I think a more "natural" value for this file would be "-smp 2". I think anything that needs more than that should explicitly should --qemu_args. Thoughts? [1] tested with --qemu_args='-smp 4' --qemu_args='-smp 8' and I see the following in the test.log smpboot: Allowing 8 CPUs, 0 hotplug CPUs so QEMU respects the last value passed in, as expected. > > The problem, of course, is that the --kconfig_add flags don't allow us > to override anything explicitly stated in either the kunitconfig or > qemu_config (and I imagine there could be problems with --qemu_config, > too). This patch would fix that. https://lore.kernel.org/linux-kselftest/20220519164512.3180360-1-dlatypov@xxxxxxxxxx It introduces an overwriting priority of * --kconfig_add * kunitconfig / --kunitconfig * qemu_config
