Re: linux-next: build failure after merge of the rcu tree

Paul E. McKenney
2020-06-25T03:45:55Z

On Thu, Jun 25, 2020 at 12:57:53PM +1000, Stephen Rothwell wrote:
> Hi all,
>
> After merging the rcu tree, today's linux-next build (powerpc
> ppc64_defconfig) failed like this:
>
> kernel/rcu/tree.c: In function 'rcu_dynticks_eqs_enter':
> kernel/rcu/tree.c:251:8: error: implicit declaration of function 'arch_atomic_add_return'; did you mean 'atomic_add_return'? [-Werror=implicit-function-declaration]
> 251 | seq = arch_atomic_add_return(RCU_DYNTICK_CTRL_CTR, &rdp->dynticks);
> | ^~~~~~~~~~~~~~~~~~~~~~
> | atomic_add_return
> kernel/rcu/tree.c: In function 'rcu_dynticks_eqs_exit':
> kernel/rcu/tree.c:281:3: error: implicit declaration of function 'arch_atomic_andnot'; did you mean 'atomic_andnot'? [-Werror=implicit-function-declaration]
> 281 | arch_atomic_andnot(RCU_DYNTICK_CTRL_MASK, &rdp->dynticks);
> | ^~~~~~~~~~~~~~~~~~
> | atomic_andnot
> kernel/rcu/tree.c: In function 'rcu_dynticks_curr_cpu_in_eqs':
> kernel/rcu/tree.c:314:11: error: implicit declaration of function 'arch_atomic_read'; did you mean 'atomic_read'? [-Werror=implicit-function-declaration]
> 314 | return !(arch_atomic_read(&rdp->dynticks) & RCU_DYNTICK_CTRL_CTR);
> | ^~~~~~~~~~~~~~~~
> | atomic_read
>
> Caused by commit
>
> d2f8491368e5 ("rcu: Fixup noinstr warnings")
>
> I reverted that commit for today.

MIPS doesn't much like it, either. I hope to get an update tomorrow.

Apologies for the hassle!

Thanx, Paul