sched_ext: Print core event count in scx_central scheduler

Modify the scx_central scheduler to print the core event counter
every second.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/tools/sched_ext/scx_central.bpf.c b/tools/sched_ext/scx_central.bpf.c
index 50bc1737c167a174955458fc1b608a592b43c11d..376c14d5dd0d98cdee3b2e6106650e3ecd3ed0ca 100644 (file)
--- a/tools/sched_ext/scx_central.bpf.c
+++ b/tools/sched_ext/scx_central.bpf.c
@@ -256,6 +256,7 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer)
        u64 now = scx_bpf_now();
        u64 nr_to_kick = nr_queued;
        s32 i, curr_cpu;
+       struct scx_event_stats events;
 
        curr_cpu = bpf_get_smp_processor_id();
        if (timer_pinned && (curr_cpu != central_cpu)) {
@@ -291,6 +292,26 @@ static int central_timerfn(void *map, int *key, struct bpf_timer *timer)
 
        bpf_timer_start(timer, TIMER_INTERVAL_NS, BPF_F_TIMER_CPU_PIN);
        __sync_fetch_and_add(&nr_timers, 1);
+
+       /* print event counters every second */
+       if (nr_timers % 1000 == 0) {
+               scx_bpf_events(&events, sizeof(events));
+
+               bpf_printk("%35s: %llu\n", "SCX_EV_SELECT_CPU_FALLBACK",
+                          scx_read_event(&events, SCX_EV_SELECT_CPU_FALLBACK));
+               bpf_printk("%35s: %llu\n", "SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE",
+                          scx_read_event(&events, SCX_EV_DISPATCH_LOCAL_DSQ_OFFLINE));
+               bpf_printk("%35s: %llu\n", "SCX_EV_DISPATCH_KEEP_LAST",
+                          scx_read_event(&events, SCX_EV_DISPATCH_KEEP_LAST));
+               bpf_printk("%35s: %llu\n", "SCX_EV_ENQ_SKIP_EXITING",
+                          scx_read_event(&events, SCX_EV_ENQ_SKIP_EXITING));
+               bpf_printk("%35s: %llu\n", "SCX_EV_BYPASS_DURATION",
+                          scx_read_event(&events, SCX_EV_BYPASS_DURATION));
+               bpf_printk("%35s: %llu\n", "SCX_EV_BYPASS_DISPATCH",
+                          scx_read_event(&events, SCX_EV_BYPASS_DISPATCH));
+               bpf_printk("%35s: %llu\n", "SCX_EV_BYPASS_ACTIVATE",
+                          scx_read_event(&events, SCX_EV_BYPASS_ACTIVATE));
+       }
        return 0;
 }