On Wed 2021-01-06 12:29:12, David Gow wrote: > On Wed, Jan 6, 2021 at 3:52 AM Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On 1/5/21 11:57 AM, Andy Shevchenko wrote: > > > On Tue, Jan 05, 2021 at 09:34:33AM -0700, Shuah Khan wrote: > > >> On 1/5/21 9:21 AM, Petr Mladek wrote: > > >>> On Mon 2021-01-04 09:23:57, Shuah Khan wrote: > > >>>> On 12/22/20 4:11 AM, Andy Shevchenko wrote: > > >>>>> On Mon, Dec 21, 2020 at 11:39:00PM -0800, David Gow wrote: > > >>>>>> kunit_tool relies on the UML console outputting printk() output to the > > >>>>>> tty in order to get results. Since the default console driver could > > >>>>>> change, pass 'console=tty' to the kernel. > > >>>>>> > > >>>>>> This is triggered by a change[1] to use ttynull as a fallback console > > >>>>>> driver which -- by chance or by design -- seems to have changed the > > >>>>>> default console output on UML, breaking kunit_tool. While this may be > > >>>>>> fixed, we should be less fragile to such changes in the default. > > >>>>>> > > >>>>>> [1]: > > >>>>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e > > >>>>> > > >>>>> Reported-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > >>>>> Tested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > >>>>> > > >>>> > > >>>> Thank you all. Now in linux-kselftest kunit-fixes branch. > > >>>> > > >>>> Will send this up for rc3. > > >>>> > > >>>> Sorry for the delay - have been away from the keyboard for a > > >>>> bit. > > >>> > > >>> JFYI, I am not sure that this is the right solution. I am > > >>> looking into it, see > > >>> https://lore.kernel.org/linux-kselftest/X%2FSRA1P8t+ONZFKb@alley/ > > >>> for more details. > > >>> > > >> > > >> Thanks Petr. I will hold off on sending the patch up to Linus and > > >> let you find a the right solution. > > > > > > Please. leave it in Linux Next at least. Otherwise kunit will be broken for a > > > long time which is not good. > > > > > > > > > > Yes. That is the plan. It will be in there until real fix comes in. The real fix would be too complicated for 5.11-rc3. Instead, I proposed to revert the problematic commit, see https://lore.kernel.org/lkml/20210107164400.17904-2-pmladek@xxxxxxxx/ I would like to push it for 5.11-rc3. > Personally, I think that this patch makes some sense to keep even if > the underlying issue with ttynull is resolved. Given that kunit.py > requires the console output, explicitly stating we want console=tty > set is probably worth doing rather than relying on it being the > default. I agree that the patch makes sense on its own. kunit depends on the particular console. Note that "tty" is actually the UML-specific stdio console implemented in arch/um/drivers/stdio_console.c. Best Regards, Petr
