2023-07-11 03:00:28

by Miaohe Lin

Subject: [PATCH] cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED

Put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED to fix the warning
of 'cgroup_tryget_css' defined but not used [-Wunused-function] when
CONFIG_CGROUP_SCHED is disabled.

Signed-off-by: Miaohe Lin <[email protected]>
---
kernel/cgroup/cgroup.c | 44 +++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index b990eda6b3cd..46401157028e 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -492,28 +492,6 @@ static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp,
return &cgrp->self;
}

-/**
- * cgroup_tryget_css - try to get a cgroup's css for the specified subsystem
- * @cgrp: the cgroup of interest
- * @ss: the subsystem of interest
- *
- * Find and get @cgrp's css associated with @ss. If the css doesn't exist
- * or is offline, %NULL is returned.
- */
-static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp,
- struct cgroup_subsys *ss)
-{
- struct cgroup_subsys_state *css;
-
- rcu_read_lock();
- css = cgroup_css(cgrp, ss);
- if (css && !css_tryget_online(css))
- css = NULL;
- rcu_read_unlock();
-
- return css;
-}
-
/**
* cgroup_e_css_by_mask - obtain a cgroup's effective css for the specified ss
* @cgrp: the cgroup of interest
@@ -3655,6 +3633,28 @@ static int cgroup_stat_show(struct seq_file *seq, void *v)
}

#ifdef CONFIG_CGROUP_SCHED
+/**
+ * cgroup_tryget_css - try to get a cgroup's css for the specified subsystem
+ * @cgrp: the cgroup of interest
+ * @ss: the subsystem of interest
+ *
+ * Find and get @cgrp's css associated with @ss. If the css doesn't exist
+ * or is offline, %NULL is returned.
+ */
+static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp,
+ struct cgroup_subsys *ss)
+{
+ struct cgroup_subsys_state *css;
+
+ rcu_read_lock();
+ css = cgroup_css(cgrp, ss);
+ if (css && !css_tryget_online(css))
+ css = NULL;
+ rcu_read_unlock();
+
+ return css;
+}
+
static int cgroup_extra_stat_show(struct seq_file *seq, int ssid)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;
--
2.33.0

2023-07-11 07:38:03

by Kamalesh Babulal

Subject: Re: [PATCH] cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED

On 7/11/23 08:08, Miaohe Lin wrote:
> Put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED to fix the warning
> of 'cgroup_tryget_css' defined but not used [-Wunused-function] when
> CONFIG_CGROUP_SCHED is disabled.
>
> Signed-off-by: Miaohe Lin <[email protected]>
> ---
> kernel/cgroup/cgroup.c | 44 +++++++++++++++++++++---------------------
> 1 file changed, 22 insertions(+), 22 deletions(-)

Looks good to me, given that the only caller cgroup_extra_stat_show() is
guarded within CONFIG_CGROUP_SCHED (linux-next tree), it makes sense to,
also move cgroup_tryget_css() within the same ifdef block.

Reviewed-by: Kamalesh Babulal <[email protected]>

2023-07-11 21:55:31

by Tejun Heo

Subject: Re: [PATCH] cgroup: put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED

On Tue, Jul 11, 2023 at 10:38:20AM +0800, Miaohe Lin wrote:
> Put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED to fix the warning
> of 'cgroup_tryget_css' defined but not used [-Wunused-function] when
> CONFIG_CGROUP_SCHED is disabled.
>
> Signed-off-by: Miaohe Lin <[email protected]>

Applied to cgroup/for-6.6.

Thanks.

--
tejun