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

[Richard Weinberger]

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. :-)

Thanks,
//richard