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

From: Richard Weinberger
Date: Wed Jun 15 2016 - 03:05:50 EST


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.

Thanks,
//richard