Messages in this thread Patch in this message | | | Date | Sun, 19 Mar 2023 17:33:58 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [paulmck-rcu:dev.2023.03.17a 33/38] kernel/rcu/tasks.h:140:20: warning: 'tasks_rcu_exit_srcu' defined but not used |
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On Sun, Mar 19, 2023 at 03:05:43PM +0800, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2023.03.17a > head: 19d218a4b125a4dce12eb88097a9c55f7126ce8c > commit: 61eea4556e8cf92d4c9b483110a679d2652aa451 [33/38] srcu: Move work-scheduling fields from srcu_struct to srcu_usage > config: x86_64-kexec (https://download.01.org/0day-ci/archive/20230319/202303191536.XzMSyzTl-lkp@intel.com/config) > compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 > reproduce (this is a W=1 build): > # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=61eea4556e8cf92d4c9b483110a679d2652aa451 > git remote add paulmck-rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > git fetch --no-tags paulmck-rcu dev.2023.03.17a > git checkout 61eea4556e8cf92d4c9b483110a679d2652aa451 > # save the config file > mkdir build_dir && cp config build_dir/.config > make W=1 O=build_dir ARCH=x86_64 olddefconfig > make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/ > > If you fix the issue, kindly add following tag where applicable > | Reported-by: kernel test robot <lkp@intel.com> > | Link: https://lore.kernel.org/oe-kbuild-all/202303191536.XzMSyzTl-lkp@intel.com/ > > All warnings (new ones prefixed by >>): > > In file included from include/linux/srcu.h:49, > from include/linux/notifier.h:16, > from arch/x86/include/asm/uprobes.h:13, > from include/linux/uprobes.h:49, > from include/linux/mm_types.h:16, > from include/linux/sched/signal.h:13, > from kernel/rcu/update.c:26: > >> kernel/rcu/tasks.h:140:20: warning: 'tasks_rcu_exit_srcu' defined but not used [-Wunused-variable] > 140 | DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); > | ^~~~~~~~~~~~~~~~~~~ > include/linux/srcutree.h:184:38: note: in definition of macro '__DEFINE_SRCU' > 184 | is_static struct srcu_struct name = \ > | ^~~~ > kernel/rcu/tasks.h:140:1: note: in expansion of macro 'DEFINE_STATIC_SRCU' > 140 | DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); > | ^~~~~~~~~~~~~~~~~~
Good catch, thank you!
Does the patch shown below fix this?
Thanx, Paul
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commit a9b8406e51603238941dbc6fa1437f8915254ebb Author: Paul E. McKenney <paulmck@kernel.org> Date: Sun Mar 19 17:29:20 2023 -0700
rcu-tasks: Fix warning for unused tasks_rcu_exit_srcu The tasks_rcu_exit_srcu variable is used only by kernels built with CONFIG_TASKS_RCU=y, but is defined for all kernesl with CONFIG_TASKS_RCU_GENERIC=y. Therefore, in kernels built with CONFIG_TASKS_RCU_GENERIC=y but CONFIG_TASKS_RCU=n, this gives a "defined but not used" warning. This commit therefore moves this variable under CONFIG_TASKS_RCU Link: https://lore.kernel.org/oe-kbuild-all/202303191536.XzMSyzTl-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index baf7ec178155..85a874d4166b 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -136,10 +136,10 @@ static struct rcu_tasks rt_name = \ .kname = #rt_name, \ } +#ifdef CONFIG_TASKS_RCU /* Track exiting tasks in order to allow them to be waited for. */ DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu); -#ifdef CONFIG_TASKS_RCU /* Report delay in synchronize_srcu() completion in rcu_tasks_postscan(). */ static void tasks_rcu_exit_srcu_stall(struct timer_list *unused); static DEFINE_TIMER(tasks_rcu_exit_srcu_stall_timer, tasks_rcu_exit_srcu_stall);
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