diff mbox series

cgroup: minor cleanup for cgroup_local_stat_show()

Message ID 20230803113123.577023-1-linmiaohe@huawei.com
State New
Headers
Series cgroup: minor cleanup for cgroup_local_stat_show() |

Commit Message

Miaohe Lin Aug. 3, 2023, 11:31 a.m. UTC 
  Make it under CONFIG_CGROUP_SCHED to rid of __maybe_unused annotation.
Also put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED as it's only
called when CONFIG_CGROUP_SCHED. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 kernel/cgroup/cgroup.c | 63 ++++++++++++++++++++++--------------------
 1 file changed, 33 insertions(+), 30 deletions(-)

Comments

Johannes Weiner Aug. 3, 2023, 2:27 p.m. UTC | #1 
On Thu, Aug 03, 2023 at 07:31:23PM +0800, Miaohe Lin wrote:
> Make it under CONFIG_CGROUP_SCHED to rid of __maybe_unused annotation.
> Also put cgroup_tryget_css() inside CONFIG_CGROUP_SCHED as it's only
> called when CONFIG_CGROUP_SCHED. No functional change intended.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

> @@ -3686,8 +3686,9 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
>  	return ret;
>  }
>  
> -static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
> -						 struct cgroup *cgrp, int ssid)
> +#ifdef CONFIG_CGROUP_SCHED
> +static int cgroup_local_stat_show(struct seq_file *seq,
> +				  struct cgroup *cgrp, int ssid)

Andrew, this is based on "sched: add throttled time stat for throttled
children" in -next (coming in from -tip). Hence the routing through
you rather than the cgroup tree.
Andrew Morton Aug. 3, 2023, 5:05 p.m. UTC | #2 
On Thu, 3 Aug 2023 10:27:58 -0400 Johannes Weiner <hannes@cmpxchg.org> wrote:

> > @@ -3686,8 +3686,9 @@ static int cpu_stat_show(struct seq_file *seq, void *v)
> >  	return ret;
> >  }
> >  
> > -static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
> > -						 struct cgroup *cgrp, int ssid)
> > +#ifdef CONFIG_CGROUP_SCHED
> > +static int cgroup_local_stat_show(struct seq_file *seq,
> > +				  struct cgroup *cgrp, int ssid)
> 
> Andrew, this is based on "sched: add throttled time stat for throttled
> children" in -next (coming in from -tip). Hence the routing through
> you rather than the cgroup tree.

Since switching to the more gitty workflow I have lost the power to
carry patches against -next.  I could regain that power I guess, but
this is the first time the requirement has come up.

So for now I'll save this patch away for the next -rc cycle.
diff mbox series

Patch

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index c2c97529235a..e9239651cf4a 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;
@@ -3686,8 +3686,9 @@  static int cpu_stat_show(struct seq_file *seq, void *v)
 	return ret;
 }
 
-static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
-						 struct cgroup *cgrp, int ssid)
+#ifdef CONFIG_CGROUP_SCHED
+static int cgroup_local_stat_show(struct seq_file *seq,
+				  struct cgroup *cgrp, int ssid)
 {
 	struct cgroup_subsys *ss = cgroup_subsys[ssid];
 	struct cgroup_subsys_state *css;
@@ -3707,14 +3708,16 @@  static int __maybe_unused cgroup_local_stat_show(struct seq_file *seq,
 
 static int cpu_local_stat_show(struct seq_file *seq, void *v)
 {
-	struct cgroup __maybe_unused *cgrp = seq_css(seq)->cgroup;
-	int ret = 0;
+	struct cgroup *cgrp = seq_css(seq)->cgroup;
 
-#ifdef CONFIG_CGROUP_SCHED
-	ret = cgroup_local_stat_show(seq, cgrp, cpu_cgrp_id);
-#endif
-	return ret;
+	return cgroup_local_stat_show(seq, cgrp, cpu_cgrp_id);
+}
+#else
+static int cpu_local_stat_show(struct seq_file *seq, void *v)
+{
+	return 0;
 }
+#endif
 
 #ifdef CONFIG_PSI
 static int cgroup_io_pressure_show(struct seq_file *seq, void *v)