linux-kernel - [RFC 03/60] sched: Setup sched_domain_shared for all sched

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Message-Id: <20180907214047.26914-4-jschoenh@amazon.de>
Date:   Fri,  7 Sep 2018 23:39:50 +0200
From:   Jan H. Schönherr <jschoenh@...zon.de>
To:     Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     Jan H. Schönherr <jschoenh@...zon.de>,
        linux-kernel@...r.kernel.org
Subject: [RFC 03/60] sched: Setup sched_domain_shared for all sched_domains

Relax the restriction to setup a sched_domain_shared only for domains
with SD_SHARE_PKG_RESOURCES. Set it up for every domain.

This restriction was imposed since the struct was created via commit
24fc7edb92ee ("sched/core: Introduce 'struct sched_domain_shared'") for
the lack of another use case. This will change soon.

Also, move the structure definition below kernel/sched/. It is not used
outside and in the future it will carry some more internal types that
we don't want to expose.

Signed-off-by: Jan H. Schönherr <jschoenh@...zon.de>
---
 include/linux/sched/topology.h |  6 ------
 kernel/sched/sched.h           |  6 ++++++
 kernel/sched/topology.c        | 12 ++++--------
 3 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h
index 26347741ba50..530ad856372e 100644
--- a/include/linux/sched/topology.h
+++ b/include/linux/sched/topology.h
@@ -68,12 +68,6 @@ extern int sched_domain_level_max;
 
 struct sched_group;
 
-struct sched_domain_shared {
-	atomic_t	ref;
-	atomic_t	nr_busy_cpus;
-	int		has_idle_cores;
-};
-
 struct sched_domain {
 	/* These fields must be setup */
 	struct sched_domain *parent;	/* top domain must be null terminated */
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index b4d0e8a68697..f6da85447f3c 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -915,6 +915,12 @@ struct rq {
 #endif
 };
 
+struct sched_domain_shared {
+	atomic_t	ref;
+	atomic_t	nr_busy_cpus;
+	int		has_idle_cores;
+};
+
 static inline int cpu_of(struct rq *rq)
 {
 #ifdef CONFIG_SMP
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 56a0fed30c0a..8b64f3f57d50 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1184,15 +1184,11 @@ sd_init(struct sched_domain_topology_level *tl,
 		sd->idle_idx = 1;
 	}
 
-	/*
-	 * For all levels sharing cache; connect a sched_domain_shared
-	 * instance.
-	 */
-	if (sd->flags & SD_SHARE_PKG_RESOURCES) {
-		sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
-		atomic_inc(&sd->shared->ref);
+	/* Setup a shared sched_domain_shared instance */
+	sd->shared = *per_cpu_ptr(sdd->sds, sd_id);
+	atomic_inc(&sd->shared->ref);
+	if (sd->flags & SD_SHARE_PKG_RESOURCES)
 		atomic_set(&sd->shared->nr_busy_cpus, sd_weight);
-	}
 
 	sd->private = sdd;
 
-- 
2.9.3.1.gcba166c.dirty