[PATCH v5 05/17] sched/topology: Verify SD_* flags setup when sched_debug is on

Valentin Schneider valentin.schneider at arm.com
Wed Aug 12 08:52:48 EDT 2020


Now that we have some description of what we expect the flags layout to
be, we can use that to assert at runtime that the actual layout is sane.

Reviewed-by: Dietmar Eggemann <dietmar.eggemann at arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider at arm.com>
---
 kernel/sched/topology.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 865fff3ef20a..f128fcf46a41 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -29,6 +29,8 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 				  struct cpumask *groupmask)
 {
 	struct sched_group *group = sd->groups;
+	unsigned long flags = sd->flags;
+	unsigned int idx;
 
 	cpumask_clear(groupmask);
 
@@ -43,6 +45,21 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 		printk(KERN_ERR "ERROR: domain->groups does not contain CPU%d\n", cpu);
 	}
 
+	for_each_set_bit(idx, &flags, __SD_FLAG_CNT) {
+		unsigned int flag = BIT(idx);
+		unsigned int meta_flags = sd_flag_debug[idx].meta_flags;
+
+		if ((meta_flags & SDF_SHARED_CHILD) && sd->child &&
+		    !(sd->child->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in child\n",
+			       sd_flag_debug[idx].name);
+
+		if ((meta_flags & SDF_SHARED_PARENT) && sd->parent &&
+		    !(sd->parent->flags & flag))
+			printk(KERN_ERR "ERROR: flag %s set here but not in parent\n",
+			       sd_flag_debug[idx].name);
+	}
+
 	printk(KERN_DEBUG "%*s groups:", level + 1, "");
 	do {
 		if (!group) {
-- 
2.27.0




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