On 1/7/21 9:53 AM, Petr Mladek wrote:
On Wed 2021-01-06 12:29:12, David Gow wrote:
On Wed, Jan 6, 2021 at 3:52 AM Shuah Khan skhan@linuxfoundation.org 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/?i... >> >> Reported-by: Andy Shevchenko andriy.shevchenko@linux.intel.com >> Tested-by: Andy Shevchenko andriy.shevchenko@linux.intel.com >> > > 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@suse.com/ 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.
The proposal sounds like revert the problem commit https://lore.kernel.org/lkml/20210107164400.17904-2-pmladek@suse.com/
and also send kunit fix up. Sounds reasonable to me. I will send it for 5.11-rc3
thanks, -- Shuah