sched: Add HMP task migration ftrace event

Adds ftrace event for tracing task migrations using HMP
optimized scheduling.

Signed-off-by: Morten Rasmussen <Morten.Rasmussen@arm.com>

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index c8c81ec..2c261a5 100644 (file)
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -656,6 +656,34 @@ TRACE_EVENT(sched_task_usage_ratio,
                        __entry->comm, __entry->pid,
                        __entry->ratio)
 );
+
+/*
+ * Tracepoint for HMP (CONFIG_SCHED_HMP) task migrations.
+ */
+TRACE_EVENT(sched_hmp_migrate,
+
+       TP_PROTO(struct task_struct *tsk, int dest, int force),
+
+       TP_ARGS(tsk, dest, force),
+
+       TP_STRUCT__entry(
+               __array(char, comm, TASK_COMM_LEN)
+               __field(pid_t, pid)
+               __field(int,  dest)
+               __field(int,  force)
+       ),
+
+       TP_fast_assign(
+       memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+               __entry->pid   = tsk->pid;
+               __entry->dest  = dest;
+               __entry->force = force;
+       ),
+
+       TP_printk("comm=%s pid=%d dest=%d force=%d",
+                       __entry->comm, __entry->pid,
+                       __entry->dest, __entry->force)
+);
 #endif /* _TRACE_SCHED_H */
 
 /* This part must be outside protection */

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 37d2d35..5c695d2 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4651,10 +4651,16 @@ unlock:
        rcu_read_unlock();
 
 #ifdef CONFIG_SCHED_HMP
-       if (hmp_up_migration(prev_cpu, &p->se))
-               return hmp_select_faster_cpu(p, prev_cpu);
-       if (hmp_down_migration(prev_cpu, &p->se))
-               return hmp_select_slower_cpu(p, prev_cpu);
+       if (hmp_up_migration(prev_cpu, &p->se)) {
+               new_cpu = hmp_select_faster_cpu(p, prev_cpu);
+               trace_sched_hmp_migrate(p, new_cpu, 0);
+               return new_cpu;
+       }
+       if (hmp_down_migration(prev_cpu, &p->se)) {
+               new_cpu = hmp_select_slower_cpu(p, prev_cpu);
+               trace_sched_hmp_migrate(p, new_cpu, 0);
+               return new_cpu;
+       }
        /* Make sure that the task stays in its previous hmp domain */
        if (!cpumask_test_cpu(new_cpu, &hmp_cpu_domain(prev_cpu)->cpus))
                return prev_cpu;
@@ -7568,6 +7574,7 @@ static void hmp_force_up_migration(int this_cpu)
                                target->push_cpu = hmp_select_faster_cpu(p, cpu);
                                target->migrate_task = p;
                                force = 1;
+                               trace_sched_hmp_migrate(p, target->push_cpu, 1);
                        }
                }
                raw_spin_unlock_irqrestore(&target->lock, flags);