Hi,
I have tried to boot a 4.14-Kernel with the RT-patches and
PREEMPT_RT_FULL on an i.MX6UL board. Unfortunately the boot stalls at
some point and never finishes.
I did some bisecting and found out, that reverting this change: [1],
makes the board boot correctly.
Can anyone help to come up with a proper fix for this?
Thanks,
Frieder
[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/commit/?h=v4.14-rt&id=56684d21f7f8341f7a5ed1433714112f49294590
+ linux-rt-users
On 17.12.18 11:42, Frieder Schrempf wrote:
> Hi,
>
> I have tried to boot a 4.14-Kernel with the RT-patches and
> PREEMPT_RT_FULL on an i.MX6UL board. Unfortunately the boot stalls at
> some point and never finishes.
>
> I did some bisecting and found out, that reverting this change: [1],
> makes the board boot correctly.
>
> Can anyone help to come up with a proper fix for this?
>
> Thanks,
> Frieder
>
> [1]:
> https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/commit/?h=v4.14-rt&id=56684d21f7f8341f7a5ed1433714112f49294590
>
On 2018-12-19 07:50:17 [+0000], Schrempf Frieder wrote:
> + linux-rt-users
>
> On 17.12.18 11:42, Frieder Schrempf wrote:
> > Hi,
> >
> > I have tried to boot a 4.14-Kernel with the RT-patches and
> > PREEMPT_RT_FULL on an i.MX6UL board. Unfortunately the boot stalls at
> > some point and never finishes.
> >
> > I did some bisecting and found out, that reverting this change: [1],
> > makes the board boot correctly.
> >
> > Can anyone help to come up with a proper fix for this?
can you check if the hashtable is initialized twice?
> > Thanks,
> > Frieder
> >
> > [1]:
> > https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/commit/?h=v4.14-rt&id=56684d21f7f8341f7a5ed1433714112f49294590
Sebastian
Hi Sebastian,
On 19.12.18 12:36, Sebastian Andrzej Siewior wrote:
> On 2018-12-19 07:50:17 [+0000], Schrempf Frieder wrote:
>> + linux-rt-users
>>
>> On 17.12.18 11:42, Frieder Schrempf wrote:
>>> Hi,
>>>
>>> I have tried to boot a 4.14-Kernel with the RT-patches and
>>> PREEMPT_RT_FULL on an i.MX6UL board. Unfortunately the boot stalls at
>>> some point and never finishes.
>>>
>>> I did some bisecting and found out, that reverting this change: [1],
>>> makes the board boot correctly.
>>>
>>> Can anyone help to come up with a proper fix for this?
>
> can you check if the hashtable is initialized twice?
I'm not sure how to check, but I guess you are on the right track. I can
leave the init loop for dentry_hashtable in place and remove the one for
in_lookup_hashtable in vfs_caches_init_early() and this also makes the
board boot.
Could it be, that the initializing for dentry_hashtable and
in_lookup_hashtable somehow interfere?
Thanks for your help,
Frieder
>
>>> Thanks,
>>> Frieder
>>>
>>> [1]:
>>> https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/commit/?h=v4.14-rt&id=56684d21f7f8341f7a5ed1433714112f49294590
>
> Sebastian
>
On 19.12.18 14:46, Frieder Schrempf wrote:
> Hi Sebastian,
>
> On 19.12.18 12:36, Sebastian Andrzej Siewior wrote:
>> On 2018-12-19 07:50:17 [+0000], Schrempf Frieder wrote:
>>> + linux-rt-users
>>>
>>> On 17.12.18 11:42, Frieder Schrempf wrote:
>>>> Hi,
>>>>
>>>> I have tried to boot a 4.14-Kernel with the RT-patches and
>>>> PREEMPT_RT_FULL on an i.MX6UL board. Unfortunately the boot stalls at
>>>> some point and never finishes.
>>>>
>>>> I did some bisecting and found out, that reverting this change: [1],
>>>> makes the board boot correctly.
>>>>
>>>> Can anyone help to come up with a proper fix for this?
>>
>> can you check if the hashtable is initialized twice?
>
> I'm not sure how to check, but I guess you are on the right track. I can
> leave the init loop for dentry_hashtable in place and remove the one for
> in_lookup_hashtable in vfs_caches_init_early() and this also makes the
> board boot.
>
> Could it be, that the initializing for dentry_hashtable and
> in_lookup_hashtable somehow interfere?
So the source of the issue turned out to be completely unrelated to
this. Although it seems like enabling PREEMPT_RT_FULL triggered the
problem in my case.
The lockup of the kernel was caused by the SNVS RTC driver. Pulling in
this patch: [1], solved the problem.
As this patch fixes a real bug I sent a request for it to be backported
to the stable releases.
[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cd7f3a249dbed2858e6c2f30e5be7f1f7a709ee2
>>>>
>>>> [1]:
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git/commit/?h=v4.14-rt&id=56684d21f7f8341f7a5ed1433714112f49294590
>>>>
>>
>> Sebastian
>>