Re: [rcu:rcu/next 25/36] include/linux/irqflags.h:79:3: error: implicit declaration of function 'arch_irqs_disabled_flags'

[Richard Weinberger <richard@nod.at>]

Paul,

On 08.08.2016 22:35, Paul E. McKenney wrote:
> On Mon, Aug 08, 2016 at 10:12:11PM +0200, Richard Weinberger wrote:
>> Paul,
>>
>> Am 15.06.2016 um 14:45 schrieb Paul E. McKenney:
>>> On Wed, Jun 15, 2016 at 09:05:37AM +0200, Richard Weinberger wrote:
>>>> Paul,
>>>>
>>>> Am 15.06.2016 um 00:54 schrieb Paul E. McKenney:
>>>>> On Mon, Jun 06, 2016 at 02:04:03AM +0800, kbuild test robot wrote:
>>>>>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next
>>>>>> head:   13ee0de9cd2444b57ce30c4f1607b49b90aa0c38
>>>>>> commit: f251ac814fc5787765009e60d54a2bd4277350c8 [25/36] rcu: Make call_rcu_tasks() tolerate first call with irqs disabled
>>>>>> config: um-allmodconfig (attached as .config)
>>>>>> compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
>>>>>> reproduce:
>>>>>>         git checkout f251ac814fc5787765009e60d54a2bd4277350c8
>>>>>>         # save the attached .config to linux build tree
>>>>>>         make ARCH=um 
>>>>>
>>>>> My kneejerk reaction would be to make CONFIG_TASKS_RCU depend on
>>>>> !UML or something similar.
>>>>>
>>>>> Another approach would be create a arch_irqs_disabled_flags() for UML.
>>>>>
>>>>> Any preferences?
>>>>
>>>> Patches for arch_irqs_disabled_flags() support are already on LKML:
>>>> https://lkml.org/lkml/2016/6/12/162
>>>>
>>>> My plan was to merge them in the v4.8 merge window.
>>>> So having CONFIG_TASKS_RCU depend on !UML for now should be fine.
>>>> We can remove the dependency in v4.8 again.
>>>
>>> Sounds very good, thank you!
>>
>> The patch is now in Linus' tree. So, you can enable CONFIG_TASKS_RCU
>> for UML again. :-)
> 
> Very good, thank you!  I have a patch slated for the next merge window.
> If you need it sooner, please let me know.

Just noticed that CONFIG_TASKS_RCU is still disabled for UML in today's
next. Is there something missing in UML?

Thanks,
//richard