| Message ID | 20201222073900.3490607-1-davidgow@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Brendan Higgins |
| Headers | show |
| Series | kunit: tool: Force the use of the 'tty' console for UML | expand |
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@linux.intel.com> Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Thanks! > Signed-off-by: David Gow <davidgow@google.com> > Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console") > --- > tools/testing/kunit/kunit_kernel.py | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py > index 57c1724b7e5d..698358c9c0d6 100644 > --- a/tools/testing/kunit/kunit_kernel.py > +++ b/tools/testing/kunit/kunit_kernel.py > @@ -198,7 +198,7 @@ class LinuxSourceTree(object): > return self.validate_config(build_dir) > > def run_kernel(self, args=[], build_dir='', timeout=None): > - args.extend(['mem=1G']) > + args.extend(['mem=1G', 'console=tty']) > self._ops.linux_bin(args, timeout, build_dir) > outfile = get_outfile_path(build_dir) > subprocess.call(['stty', 'sane']) > -- > 2.29.2.729.g45daf8777d-goog >
On Mon, Dec 21, 2020 at 11:39 PM David Gow <davidgow@google.com> 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 > > Signed-off-by: David Gow <davidgow@google.com> > Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console") Acked-by: Brendan Higgins <brendanhiggins@google.com> Thanks for taking care of this!
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@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. thanks, -- Shuah
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@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. Best Regards, Petr
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@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. thanks, -- Shuah
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@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.
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@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. thanks, -- Shuah
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/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e > >>>>> > >>>>> 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. > Thanks, Shuah. 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. That being said, I definitely agree that this patch doesn't fix the underlying issue with UML/ttynull: it just makes the kunit.py script less sensitive to such changes (which, while unlikely, could potentially occur legitimately down the track). Cheers, -- David
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/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e > > >>>>> > > >>>>> 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. Best Regards, Petr
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/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e >>>>>>>> >>>>>>>> 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
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py index 57c1724b7e5d..698358c9c0d6 100644 --- a/tools/testing/kunit/kunit_kernel.py +++ b/tools/testing/kunit/kunit_kernel.py @@ -198,7 +198,7 @@ class LinuxSourceTree(object): return self.validate_config(build_dir) def run_kernel(self, args=[], build_dir='', timeout=None): - args.extend(['mem=1G']) + args.extend(['mem=1G', 'console=tty']) self._ops.linux_bin(args, timeout, build_dir) outfile = get_outfile_path(build_dir) subprocess.call(['stty', 'sane'])
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 Signed-off-by: David Gow <davidgow@google.com> Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console") --- tools/testing/kunit/kunit_kernel.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)