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. -- Cheers, Stephen Rothwell