[PATCH v2] sched_ext: Provides a sysfs 'events' to expose core event counters
From: Changwoo Min
Date: Fri Feb 14 2025 - 04:58:49 EST
Add a sysfs entry at /sys/kernel/sched_ext/root/events to expose core
event counters through the files system interface. Each line of the file
shows the event name and its counter value.
In addition, the format of scx_dump_event() is adjusted as the event name
gets longer.
Signed-off-by: Changwoo Min <changwoo@xxxxxxxxxx>
---
ChangeLog v1 -> v2:
- Change the format of the output to the simpler form, "%s %llu\n".
- Move the 'events' under the root/ subdir following the lifecycle of
an scx scheduler.
kernel/sched/ext.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 0c5120c6381c..4f88b782886e 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1576,7 +1576,7 @@ static DEFINE_PER_CPU(struct scx_event_stats, event_stats_cpu);
* @kind: a kind of event to dump
*/
#define scx_dump_event(s, events, kind) do { \
- dump_line(&(s), "%30s: %16llu", #kind, (events)->kind); \
+ dump_line(&(s), "%40s: %16llu", #kind, (events)->kind); \
} while (0)
@@ -4383,8 +4383,33 @@ static ssize_t scx_attr_ops_show(struct kobject *kobj,
}
SCX_ATTR(ops);
+#define scx_attr_event_show(buf, at, events, kind) ({ \
+ sysfs_emit_at(buf, at, "%s %llu\n", #kind, (events)->kind); \
+})
+
+static ssize_t scx_attr_events_show(struct kobject *kobj,
+ struct kobj_attribute *ka, char *buf)
+{
+ struct scx_event_stats events;
+ int at = 0;
+
+ scx_bpf_events(&events, sizeof(events));
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_SELECT_CPU_FALLBACK);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_DISPATCH_KEEP_LAST);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_ENQ_SKIP_EXITING);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_ENQ_SKIP_MIGRATION_DISABLED);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_ENQ_SLICE_DFL);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_BYPASS_DURATION);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_BYPASS_DISPATCH);
+ at += scx_attr_event_show(buf, at, &events, SCX_EV_BYPASS_ACTIVATE);
+ return at;
+}
+SCX_ATTR(events);
+
static struct attribute *scx_sched_attrs[] = {
&scx_attr_ops.attr,
+ &scx_attr_events.attr,
NULL,
};
ATTRIBUTE_GROUPS(scx_sched);
--
2.48.1