[ammarfaizi2-block:paulmck/linux-rcu/dev 83/131] kernel/rcu/tree.c:3778:13: error: implicit declaration of function 'preempt_mode_full'; did you mean 'preempt_model_full'?

From: kernel test robot
Date: Mon Apr 11 2022 - 14:44:58 EST


tree: https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
head: 96d35f716a63bc46750d66a5daec804997ff7cc6
commit: 78b49c815a11d5541a7492b483eb20ec6377cafe [83/131] rcu: Fix preemption mode check on synchronize_rcu[_expedited]()
config: xtensa-buildonly-randconfig-r003-20220411 (https://download.01.org/0day-ci/archive/20220412/202204120207.7OoY1hZZ-lkp@xxxxxxxxx/config)
compiler: xtensa-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/ammarfaizi2/linux-block/commit/78b49c815a11d5541a7492b483eb20ec6377cafe
git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
git checkout 78b49c815a11d5541a7492b483eb20ec6377cafe
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=xtensa SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

Note: the ammarfaizi2-block/paulmck/linux-rcu/dev HEAD 96d35f716a63bc46750d66a5daec804997ff7cc6 builds fine.
It only hurts bisectability.

All errors (new ones prefixed by >>):

kernel/rcu/tree.c: In function 'rcu_blocking_is_gp':
>> kernel/rcu/tree.c:3778:13: error: implicit declaration of function 'preempt_mode_full'; did you mean 'preempt_model_full'? [-Werror=implicit-function-declaration]
3778 | if (preempt_mode_full() || preempt_mode_rt())
| ^~~~~~~~~~~~~~~~~
| preempt_model_full
>> kernel/rcu/tree.c:3778:36: error: implicit declaration of function 'preempt_mode_rt'; did you mean 'preempt_model_rt'? [-Werror=implicit-function-declaration]
3778 | if (preempt_mode_full() || preempt_mode_rt())
| ^~~~~~~~~~~~~~~
| preempt_model_rt
cc1: some warnings being treated as errors


vim +3778 kernel/rcu/tree.c

3761
3762 /*
3763 * During early boot, any blocking grace-period wait automatically
3764 * implies a grace period. Later on, this is never the case for PREEMPTION.
3765 *
3766 * However, because a context switch is a grace period for !PREEMPTION, any
3767 * blocking grace-period wait automatically implies a grace period if
3768 * there is only one CPU online at any point time during execution of
3769 * either synchronize_rcu() or synchronize_rcu_expedited(). It is OK to
3770 * occasionally incorrectly indicate that there are multiple CPUs online
3771 * when there was in fact only one the whole time, as this just adds some
3772 * overhead: RCU still operates correctly.
3773 */
3774 static int rcu_blocking_is_gp(void)
3775 {
3776 int ret;
3777
> 3778 if (preempt_mode_full() || preempt_mode_rt())
3779 return rcu_scheduler_active == RCU_SCHEDULER_INACTIVE;
3780 might_sleep(); /* Check for RCU read-side critical section. */
3781 preempt_disable();
3782 /*
3783 * If the rcu_state.n_online_cpus counter is equal to one,
3784 * there is only one CPU, and that CPU sees all prior accesses
3785 * made by any CPU that was online at the time of its access.
3786 * Furthermore, if this counter is equal to one, its value cannot
3787 * change until after the preempt_enable() below.
3788 *
3789 * Furthermore, if rcu_state.n_online_cpus is equal to one here,
3790 * all later CPUs (both this one and any that come online later
3791 * on) are guaranteed to see all accesses prior to this point
3792 * in the code, without the need for additional memory barriers.
3793 * Those memory barriers are provided by CPU-hotplug code.
3794 */
3795 ret = READ_ONCE(rcu_state.n_online_cpus) <= 1;
3796 preempt_enable();
3797 return ret;
3798 }
3799

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