1 files changed, 61 insertions, 4 deletions

diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index fee77e15d815..6e32635e5e57 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -16,6 +16,7 @@
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
 #include <linux/sched/rt.h>
+#include <linux/sched/deadline.h>
 #include <trace/events/sched.h>
 #include "trace.h"
 
@@ -27,6 +28,8 @@ static int			wakeup_cpu;
 static int                      wakeup_current_cpu;
 static unsigned                 wakeup_prio = -1;
 static int                      wakeup_rt;
+static int                      wakeup_dl;
+static int                      tracing_dl = 0;
 
 static arch_spinlock_t wakeup_lock =
         (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -437,6 +440,7 @@ static void __wakeup_reset(struct trace_array *tr)
 {
         wakeup_cpu = -1;
         wakeup_prio = -1;
+        tracing_dl = 0;
 
         if (wakeup_task)
                 put_task_struct(wakeup_task);
@@ -472,9 +476,17 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
         tracing_record_cmdline(p);
         tracing_record_cmdline(current);
 
-        if ((wakeup_rt && !rt_task(p)) ||
-                        p->prio >= wakeup_prio ||
-                        p->prio >= current->prio)
+        /*
+         * Semantic is like this:
+         *  - wakeup tracer handles all tasks in the system, independently
+         *    from their scheduling class;
+         *  - wakeup_rt tracer handles tasks belonging to sched_dl and
+         *    sched_rt class;
+         *  - wakeup_dl handles tasks belonging to sched_dl class only.
+         */
+        if (tracing_dl || (wakeup_dl && !dl_task(p)) ||
+            (wakeup_rt && !dl_task(p) && !rt_task(p)) ||
+            (!dl_task(p) && (p->prio >= wakeup_prio || p->prio >= current->prio)))
                 return;
 
         pc = preempt_count();
@@ -486,7 +498,8 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
         arch_spin_lock(&wakeup_lock);
 
         /* check for races. */
-        if (!tracer_enabled || p->prio >= wakeup_prio)
+        if (!tracer_enabled || tracing_dl ||
+            (!dl_task(p) && p->prio >= wakeup_prio))
                 goto out_locked;
 
         /* reset the trace */
@@ -496,6 +509,15 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
         wakeup_current_cpu = wakeup_cpu;
         wakeup_prio = p->prio;
 
+        /*
+         * Once you start tracing a -deadline task, don't bother tracing
+         * another task until the first one wakes up.
+         */
+        if (dl_task(p))
+                tracing_dl = 1;
+        else
+                tracing_dl = 0;
+
         wakeup_task = p;
         get_task_struct(wakeup_task);
 
@@ -597,16 +619,25 @@ static int __wakeup_tracer_init(struct trace_array *tr)
 
 static int wakeup_tracer_init(struct trace_array *tr)
 {
+        wakeup_dl = 0;
         wakeup_rt = 0;
         return __wakeup_tracer_init(tr);
 }
 
 static int wakeup_rt_tracer_init(struct trace_array *tr)
 {
+        wakeup_dl = 0;
         wakeup_rt = 1;
         return __wakeup_tracer_init(tr);
 }
 
+static int wakeup_dl_tracer_init(struct trace_array *tr)
+{
+        wakeup_dl = 1;
+        wakeup_rt = 0;
+        return __wakeup_tracer_init(tr);
+}
+
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
         int lat_flag = save_flags & TRACE_ITER_LATENCY_FMT;
@@ -674,6 +705,28 @@ static struct tracer wakeup_rt_tracer __read_mostly =
         .use_max_tr     = true,
 };
 
+static struct tracer wakeup_dl_tracer __read_mostly =
+{
+        .name           = "wakeup_dl",
+        .init           = wakeup_dl_tracer_init,
+        .reset          = wakeup_tracer_reset,
+        .start          = wakeup_tracer_start,
+        .stop           = wakeup_tracer_stop,
+        .wait_pipe      = poll_wait_pipe,
+        .print_max      = true,
+        .print_header   = wakeup_print_header,
+        .print_line     = wakeup_print_line,
+        .flags          = &tracer_flags,
+        .set_flag       = wakeup_set_flag,
+        .flag_changed   = wakeup_flag_changed,
+#ifdef CONFIG_FTRACE_SELFTEST
+        .selftest    = trace_selftest_startup_wakeup,
+#endif
+        .open           = wakeup_trace_open,
+        .close          = wakeup_trace_close,
+        .use_max_tr     = true,
+};
+
 __init static int init_wakeup_tracer(void)
 {
         int ret;
@@ -686,6 +739,10 @@ __init static int init_wakeup_tracer(void)
         if (ret)
                 return ret;
 
+        ret = register_tracer(&wakeup_dl_tracer);
+        if (ret)
+                return ret;
+
         return 0;
 }
 core_initcall(init_wakeup_tracer);