[PATCH] sched: core: fix compilation error when cgroup not selected

[PATCH] sched: core: fix compilation error when cgroup not selected

[Qais Yousef]

When cgroup is disabled the following compilation error was hit

	kernel/sched/core.c: In function ‘uclamp_update_active_tasks’:
	kernel/sched/core.c:1081:23: error: storage size of ‘it’ isn’t known
	  struct css_task_iter it;
			       ^~
	kernel/sched/core.c:1084:2: error: implicit declaration of function ‘css_task_iter_start’; did you mean ‘__sg_page_iter_start’? [-Werror=implicit-function-declaration]
	  css_task_iter_start(css, 0, &it);
	  ^~~~~~~~~~~~~~~~~~~
	  __sg_page_iter_start
	kernel/sched/core.c:1085:14: error: implicit declaration of function ‘css_task_iter_next’; did you mean ‘__sg_page_iter_next’? [-Werror=implicit-function-declaration]
	  while ((p = css_task_iter_next(&it))) {
		      ^~~~~~~~~~~~~~~~~~
		      __sg_page_iter_next
	kernel/sched/core.c:1091:2: error: implicit declaration of function ‘css_task_iter_end’; did you mean ‘get_task_cred’? [-Werror=implicit-function-declaration]
	  css_task_iter_end(&it);
	  ^~~~~~~~~~~~~~~~~
	  get_task_cred
	kernel/sched/core.c:1081:23: warning: unused variable ‘it’ [-Wunused-variable]
	  struct css_task_iter it;
			       ^~
	cc1: some warnings being treated as errors
	make[2]: *** [kernel/sched/core.o] Error 1

Fix by protetion uclamp_update_active_tasks() with
CONFIG_UCLAMP_TASK_GROUP

Fixes: babbe170e053 ("sched/uclamp: Update CPU's refcount on TG's clamp changes")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dd05a378631a..afd4d8028771 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1073,6 +1073,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
 	task_rq_unlock(rq, p, &rf);
 }
 
+#ifdef CONFIG_UCLAMP_TASK_GROUP
 static inline void
 uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 			   unsigned int clamps)
@@ -1091,7 +1092,6 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 	css_task_iter_end(&it);
 }
 
-#ifdef CONFIG_UCLAMP_TASK_GROUP
 static void cpu_util_update_eff(struct cgroup_subsys_state *css);
 static void uclamp_update_root_tg(void)
 {
-- 
2.17.1

Re: [PATCH] sched: core: fix compilation error when cgroup not selected

[Patrick Bellasi]

[ +Randy ]

Hi Qais,

On 05-Nov 11:22, Qais Yousef wrote:
> When cgroup is disabled the following compilation error was hit
> 
> 	kernel/sched/core.c: In function ‘uclamp_update_active_tasks’:
> 	kernel/sched/core.c:1081:23: error: storage size of ‘it’ isn’t known
> 	  struct css_task_iter it;
> 			       ^~
> 	kernel/sched/core.c:1084:2: error: implicit declaration of function ‘css_task_iter_start’; did you mean ‘__sg_page_iter_start’? [-Werror=implicit-function-declaration]
> 	  css_task_iter_start(css, 0, &it);
> 	  ^~~~~~~~~~~~~~~~~~~
> 	  __sg_page_iter_start
> 	kernel/sched/core.c:1085:14: error: implicit declaration of function ‘css_task_iter_next’; did you mean ‘__sg_page_iter_next’? [-Werror=implicit-function-declaration]
> 	  while ((p = css_task_iter_next(&it))) {
> 		      ^~~~~~~~~~~~~~~~~~
> 		      __sg_page_iter_next
> 	kernel/sched/core.c:1091:2: error: implicit declaration of function ‘css_task_iter_end’; did you mean ‘get_task_cred’? [-Werror=implicit-function-declaration]
> 	  css_task_iter_end(&it);
> 	  ^~~~~~~~~~~~~~~~~
> 	  get_task_cred
> 	kernel/sched/core.c:1081:23: warning: unused variable ‘it’ [-Wunused-variable]
> 	  struct css_task_iter it;
> 			       ^~
> 	cc1: some warnings being treated as errors
> 	make[2]: *** [kernel/sched/core.o] Error 1
> 
> Fix by protetion uclamp_update_active_tasks() with
> CONFIG_UCLAMP_TASK_GROUP
> 
> Fixes: babbe170e053 ("sched/uclamp: Update CPU's refcount on TG's clamp changes")
> Signed-off-by: Qais Yousef <qais.yousef@arm.com>

Thanks for posting this again.

We now have three "versions" of this same fix, including:
 - the original bug report by Randy and a fix from me here:
   Message-ID: <8736gv2gbv.fsf@arm.com>
   https://lore.kernel.org/linux-next/8736gv2gbv.fsf@arm.com/
 - and a follow up patch from Arnd:
   Message-ID: <20190918195957.2220297-1-arnd@arndb.de>
   https://lore.kernel.org/lkml/20190918195957.2220297-1-arnd@arndb.de/

So, I guess now we just have to pick the one with the changelog we
prefer. :)

In all cases we should probably add:

  Reported-by: Randy Dunlap <rdunlap@infradead.org>
  Tested-by: Randy Dunlap <rdunlap@infradead.org>

Best,
Patrick

> ---
>  kernel/sched/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index dd05a378631a..afd4d8028771 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1073,6 +1073,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
>  	task_rq_unlock(rq, p, &rf);
>  }
>  
> +#ifdef CONFIG_UCLAMP_TASK_GROUP
>  static inline void
>  uclamp_update_active_tasks(struct cgroup_subsys_state *css,
>  			   unsigned int clamps)
> @@ -1091,7 +1092,6 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
>  	css_task_iter_end(&it);
>  }
>  
> -#ifdef CONFIG_UCLAMP_TASK_GROUP
>  static void cpu_util_update_eff(struct cgroup_subsys_state *css);
>  static void uclamp_update_root_tg(void)
>  {
> -- 
> 2.17.1
> 

-- 
#include <best/regards.h>

Patrick Bellasi

Re: [PATCH] sched: core: fix compilation error when cgroup not selected

[Qais Yousef]

Hi Patrick

On 11/07/19 07:25, Patrick Bellasi wrote:

[...]

> Thanks for posting this again.
> 
> We now have three "versions" of this same fix, including:
>  - the original bug report by Randy and a fix from me here:
>    Message-ID: <8736gv2gbv.fsf@arm.com>
>    https://lore.kernel.org/linux-next/8736gv2gbv.fsf@arm.com/
>  - and a follow up patch from Arnd:
>    Message-ID: <20190918195957.2220297-1-arnd@arndb.de>
>    https://lore.kernel.org/lkml/20190918195957.2220297-1-arnd@arndb.de/

Oh I should have done my homework better. FWIW I caught this on 5.4-rc6 so
that's why I didn't think there was a fix posted.

I don't mind which version gets picked. But if it can go in before 5.4 is
released that'd be great.

Thanks

--
Qais Yousef

Re: [PATCH] sched: core: fix compilation error when cgroup not selected

[Peter Zijlstra]

On Thu, Nov 07, 2019 at 07:25:25AM +0000, Patrick Bellasi wrote:
> [ +Randy ]
> 
> Hi Qais,
> 
> On 05-Nov 11:22, Qais Yousef wrote:
> > When cgroup is disabled the following compilation error was hit
> > 
> > 	kernel/sched/core.c: In function ‘uclamp_update_active_tasks’:
> > 	kernel/sched/core.c:1081:23: error: storage size of ‘it’ isn’t known
> > 	  struct css_task_iter it;
> > 			       ^~
> > 	kernel/sched/core.c:1084:2: error: implicit declaration of function ‘css_task_iter_start’; did you mean ‘__sg_page_iter_start’? [-Werror=implicit-function-declaration]
> > 	  css_task_iter_start(css, 0, &it);
> > 	  ^~~~~~~~~~~~~~~~~~~
> > 	  __sg_page_iter_start
> > 	kernel/sched/core.c:1085:14: error: implicit declaration of function ‘css_task_iter_next’; did you mean ‘__sg_page_iter_next’? [-Werror=implicit-function-declaration]
> > 	  while ((p = css_task_iter_next(&it))) {
> > 		      ^~~~~~~~~~~~~~~~~~
> > 		      __sg_page_iter_next
> > 	kernel/sched/core.c:1091:2: error: implicit declaration of function ‘css_task_iter_end’; did you mean ‘get_task_cred’? [-Werror=implicit-function-declaration]
> > 	  css_task_iter_end(&it);
> > 	  ^~~~~~~~~~~~~~~~~
> > 	  get_task_cred
> > 	kernel/sched/core.c:1081:23: warning: unused variable ‘it’ [-Wunused-variable]
> > 	  struct css_task_iter it;
> > 			       ^~
> > 	cc1: some warnings being treated as errors
> > 	make[2]: *** [kernel/sched/core.o] Error 1
> > 
> > Fix by protetion uclamp_update_active_tasks() with
> > CONFIG_UCLAMP_TASK_GROUP
> > 
> > Fixes: babbe170e053 ("sched/uclamp: Update CPU's refcount on TG's clamp changes")
> > Signed-off-by: Qais Yousef <qais.yousef@arm.com>
> 
> Thanks for posting this again.
> 
> We now have three "versions" of this same fix, including:
>  - the original bug report by Randy and a fix from me here:
>    Message-ID: <8736gv2gbv.fsf@arm.com>
>    https://lore.kernel.org/linux-next/8736gv2gbv.fsf@arm.com/
>  - and a follow up patch from Arnd:
>    Message-ID: <20190918195957.2220297-1-arnd@arndb.de>
>    https://lore.kernel.org/lkml/20190918195957.2220297-1-arnd@arndb.de/
> 
> So, I guess now we just have to pick the one with the changelog we
> prefer. :)
> 
> In all cases we should probably add:
> 
>   Reported-by: Randy Dunlap <rdunlap@infradead.org>
>   Tested-by: Randy Dunlap <rdunlap@infradead.org>

Argh, ok, I missed them all too. Picked up this one for sched/urgent and
added the above.

Thanks!

[tip: sched/urgent] sched/core: Fix compilation error when cgroup not selected

[tip-bot2 for Qais Yousef]

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID:     e3b8b6a0d12cccf772113d6b5c1875192186fbd4
Gitweb:        https://git.kernel.org/tip/e3b8b6a0d12cccf772113d6b5c1875192186fbd4
Author:        Qais Yousef <qais.yousef@arm.com>
AuthorDate:    Tue, 05 Nov 2019 11:22:12 
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Fri, 08 Nov 2019 22:34:14 +01:00

sched/core: Fix compilation error when cgroup not selected

When cgroup is disabled the following compilation error was hit

	kernel/sched/core.c: In function ‘uclamp_update_active_tasks’:
	kernel/sched/core.c:1081:23: error: storage size of ‘it’ isn’t known
	  struct css_task_iter it;
			       ^~
	kernel/sched/core.c:1084:2: error: implicit declaration of function ‘css_task_iter_start’; did you mean ‘__sg_page_iter_start’? [-Werror=implicit-function-declaration]
	  css_task_iter_start(css, 0, &it);
	  ^~~~~~~~~~~~~~~~~~~
	  __sg_page_iter_start
	kernel/sched/core.c:1085:14: error: implicit declaration of function ‘css_task_iter_next’; did you mean ‘__sg_page_iter_next’? [-Werror=implicit-function-declaration]
	  while ((p = css_task_iter_next(&it))) {
		      ^~~~~~~~~~~~~~~~~~
		      __sg_page_iter_next
	kernel/sched/core.c:1091:2: error: implicit declaration of function ‘css_task_iter_end’; did you mean ‘get_task_cred’? [-Werror=implicit-function-declaration]
	  css_task_iter_end(&it);
	  ^~~~~~~~~~~~~~~~~
	  get_task_cred
	kernel/sched/core.c:1081:23: warning: unused variable ‘it’ [-Wunused-variable]
	  struct css_task_iter it;
			       ^~
	cc1: some warnings being treated as errors
	make[2]: *** [kernel/sched/core.o] Error 1

Fix by protetion uclamp_update_active_tasks() with
CONFIG_UCLAMP_TASK_GROUP

Fixes: babbe170e053 ("sched/uclamp: Update CPU's refcount on TG's clamp changes")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Patrick Bellasi <patrick.bellasi@matbug.net>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Ben Segall <bsegall@google.com>
Link: https://lkml.kernel.org/r/20191105112212.596-1-qais.yousef@arm.com
---
 kernel/sched/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dd05a37..afd4d80 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1073,6 +1073,7 @@ uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
 	task_rq_unlock(rq, p, &rf);
 }
 
+#ifdef CONFIG_UCLAMP_TASK_GROUP
 static inline void
 uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 			   unsigned int clamps)
@@ -1091,7 +1092,6 @@ uclamp_update_active_tasks(struct cgroup_subsys_state *css,
 	css_task_iter_end(&it);
 }
 
-#ifdef CONFIG_UCLAMP_TASK_GROUP
 static void cpu_util_update_eff(struct cgroup_subsys_state *css);
 static void uclamp_update_root_tg(void)
 {