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/[email protected]/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 <[email protected]>
| Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
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);
| ^~~~~~~~~~~~~~~~~~
vim +/tasks_rcu_exit_srcu +140 kernel/rcu/tasks.h
07e105158d97b4 Paul E. McKenney 2020-03-02 138
eacd6f04a13331 Paul E. McKenney 2020-03-02 139 /* Track exiting tasks in order to allow them to be waited for. */
eacd6f04a13331 Paul E. McKenney 2020-03-02 @140 DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu);
eacd6f04a13331 Paul E. McKenney 2020-03-02 141
:::::: The code at line 140 was first introduced by commit
:::::: eacd6f04a1333187dd3e96e5635c0edce0a2e354 rcu-tasks: Move Tasks RCU to its own file
:::::: TO: Paul E. McKenney <[email protected]>
:::::: CC: Paul E. McKenney <[email protected]>
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
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/[email protected]/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 <[email protected]>
> | Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
>
> 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);
> | ^~~~~~~~~~~~~~~~~~
It is true that if you build a kernel with CONFIG_TASKS_RCU_GENERIC=y and
CONFIG_TASKS_RCU=n, you will get this warning. I am at a loss as to why
this commit would have changed that, but in any case it does need a fix.
Thank you for catching it!
Thanx, Paul
> vim +/tasks_rcu_exit_srcu +140 kernel/rcu/tasks.h
>
> 07e105158d97b4 Paul E. McKenney 2020-03-02 138
> eacd6f04a13331 Paul E. McKenney 2020-03-02 139 /* Track exiting tasks in order to allow them to be waited for. */
> eacd6f04a13331 Paul E. McKenney 2020-03-02 @140 DEFINE_STATIC_SRCU(tasks_rcu_exit_srcu);
> eacd6f04a13331 Paul E. McKenney 2020-03-02 141
>
> :::::: The code at line 140 was first introduced by commit
> :::::: eacd6f04a1333187dd3e96e5635c0edce0a2e354 rcu-tasks: Move Tasks RCU to its own file
>
> :::::: TO: Paul E. McKenney <[email protected]>
> :::::: CC: Paul E. McKenney <[email protected]>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests
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/[email protected]/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 <[email protected]>
> | Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
>
> 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
------------------------------------------------------------------------
commit a9b8406e51603238941dbc6fa1437f8915254ebb
Author: Paul E. McKenney <[email protected]>
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/[email protected]/
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
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);
Hi Paul,
On Sun, 2023-03-19 at 17:33 -0700, Paul E. McKenney wrote:
> 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/[email protected]/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 <[email protected]>
> > > Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> >
> > 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?
We've tested the patch and the build warning is fixed by it. Thanks.
--
Best Regards,
Yujie
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit a9b8406e51603238941dbc6fa1437f8915254ebb
> Author: Paul E. McKenney <[email protected]>
> 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/[email protected]/
> Reported-by: kernel test robot <[email protected]>
> Signed-off-by: Paul E. McKenney <[email protected]>
>
> 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);
>
On Tue, Mar 21, 2023 at 02:49:08AM +0000, Liu, Yujie wrote:
> Hi Paul,
>
> On Sun, 2023-03-19 at 17:33 -0700, Paul E. McKenney wrote:
> > 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/[email protected]/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 <[email protected]>
> > > > Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > >
> > > 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?
>
> We've tested the patch and the build warning is fixed by it. Thanks.
Thank you! May I apply your Tested-by?
Thanx, Paul
> --
> Best Regards,
> Yujie
>
> > ????????????????????????????????????????????????????????Thanx, Paul
> >
> > ------------------------------------------------------------------------
> >
> > commit a9b8406e51603238941dbc6fa1437f8915254ebb
> > Author: Paul E. McKenney <[email protected]>
> > 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/[email protected]/
> > ??? Reported-by: kernel test robot <[email protected]>
> > ??? Signed-off-by: Paul E. McKenney <[email protected]>
> >
> > 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);
> >
>
On Mon, 2023-03-20 at 21:18 -0700, Paul E. McKenney wrote:
> On Tue, Mar 21, 2023 at 02:49:08AM +0000, Liu, Yujie wrote:
> > Hi Paul,
> >
> > On Sun, 2023-03-19 at 17:33 -0700, Paul E. McKenney wrote:
> > > 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
> > > > [email protected]/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 <[email protected]>
> > > > > Link:
> > > > > https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > > >
> > > > 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?
> >
> > We've tested the patch and the build warning is fixed by it.
> > Thanks.
>
> Thank you! May I apply your Tested-by?
Sure, with pleasure.
Tested-by: Yujie Liu <[email protected]>
Thanks.
> Thanx, Paul
>
> > --
> > Best Regards,
> > Yujie
> >
> > > Thanx,
> > > Paul
> > >
> > > -----------------------------------------------------------------
> > > -------
> > >
> > > commit a9b8406e51603238941dbc6fa1437f8915254ebb
> > > Author: Paul E. McKenney <[email protected]>
> > > 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/[email protected]/
> > > Reported-by: kernel test robot <[email protected]>
> > > Signed-off-by: Paul E. McKenney <[email protected]>
> > >
> > > 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);
> > >
> >
>
On Tue, Mar 21, 2023 at 06:16:04AM +0000, Liu, Yujie wrote:
> On Mon, 2023-03-20 at 21:18 -0700, Paul E. McKenney wrote:
> > On Tue, Mar 21, 2023 at 02:49:08AM +0000, Liu, Yujie wrote:
> > > Hi Paul,
> > >
> > > On Sun, 2023-03-19 at 17:33 -0700, Paul E. McKenney wrote:
> > > > 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
> > > > > [email protected]/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 <[email protected]>
> > > > > > Link:
> > > > > > https://lore.kernel.org/oe-kbuild-all/[email protected]/
> > > > >
> > > > > 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?
> > >
> > > We've tested the patch and the build warning is fixed by it.
> > > Thanks.
> >
> > Thank you!? May I apply your Tested-by?
>
> Sure, with pleasure.
>
> Tested-by: Yujie Liu <[email protected]>
Thank you, and I will apply on my next rebase.
Thanx, Paul
> Thanks.
>
> > ????????????????????????????????????????????????????????Thanx, Paul
> >
> > > --
> > > Best Regards,
> > > Yujie
> > >
> > > > ????????????????????????????????????????????????????????Thanx,
> > > > Paul
> > > >
> > > > -----------------------------------------------------------------
> > > > -------
> > > >
> > > > commit a9b8406e51603238941dbc6fa1437f8915254ebb
> > > > Author: Paul E. McKenney <[email protected]>
> > > > 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/[email protected]/
> > > > ??? Reported-by: kernel test robot <[email protected]>
> > > > ??? Signed-off-by: Paul E. McKenney <[email protected]>
> > > >
> > > > 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);
> > > >
> > >
> >
>