Re: [RFC PATCH 2/2] sched: Put task_group::idle under CONFIG_GROUP_SCHED_WEIGHT

[Tejun Heo <tj@kernel.org>]

Hello,

I applied the patch to sched_ext/for-6.12-fixes with some edits. There's no
strong reason to keep idle in that particular location and it's easier to
move it upward out of CONFIG_FAIR_GROUP_SCHED block.

Thanks.

------ 8< ------
From 7ebd84d627e40cb9fb12b338588e81b6cca371e3 Mon Sep 17 00:00:00 2001
From: Yu Liao <liaoyu15@huawei.com>
Date: Mon, 23 Sep 2024 21:54:31 +0800
Subject: [PATCH] sched: Put task_group::idle under CONFIG_GROUP_SCHED_WEIGHT

When build with CONFIG_GROUP_SCHED_WEIGHT && !CONFIG_FAIR_GROUP_SCHED,
the idle member is not defined:

kernel/sched/ext.c:3701:16: error: 'struct task_group' has no member named 'idle'
  3701 |         if (!tg->idle)
       |                ^~

Fix this by putting 'idle' under new CONFIG_GROUP_SCHED_WEIGHT.

tj: Move idle field upward to avoid breaking up CONFIG_FAIR_GROUP_SCHED block.

Fixes: e179e80c5d4f ("sched: Introduce CONFIG_GROUP_SCHED_WEIGHT")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202409220859.UiCAoFOW-lkp@intel.com/
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/sched/sched.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 91d14061fdca..b1c3588a8f00 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -432,16 +432,17 @@ struct cfs_bandwidth {
 struct task_group {
 	struct cgroup_subsys_state css;
 
+#ifdef CONFIG_GROUP_SCHED_WEIGHT
+	/* A positive value indicates that this is a SCHED_IDLE group. */
+	int			idle;
+#endif
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	/* schedulable entities of this group on each CPU */
 	struct sched_entity	**se;
 	/* runqueue "owned" by this group on each CPU */
 	struct cfs_rq		**cfs_rq;
 	unsigned long		shares;
-
-	/* A positive value indicates that this is a SCHED_IDLE group. */
-	int			idle;
-
 #ifdef	CONFIG_SMP
 	/*
 	 * load_avg can be heavily contended at clock tick time, so put
-- 
2.46.0