P-RES: keep track in per-task state of whether it suspended

Checking state->scheduled is not accurate when bandwidth inheritance
is applied.

1 files changed, 9 insertions, 3 deletions

diff --git a/litmus/sched_pres.c b/litmus/sched_pres.c
index 6126852ec8ab..34b096dece90 100644
--- a/litmus/sched_pres.c
+++ b/litmus/sched_pres.c
@@ -17,6 +17,7 @@
 struct pres_task_state {
         struct task_client res_info;
         int cpu;
+        bool has_departed;
 };
 
 struct pres_cpu_state {
@@ -49,6 +50,7 @@ static void task_departs(struct task_struct *tsk, int job_complete)
         client = &state->res_info.client;
 
         res->ops->client_departs(res, client, job_complete);
+        state->has_departed = true;
 }
 
 static void task_arrives(struct task_struct *tsk)
@@ -60,6 +62,7 @@ static void task_arrives(struct task_struct *tsk)
         res    = state->res_info.client.reservation;
         client = &state->res_info.client;
 
+        state->has_departed = false;
         res->ops->client_arrives(res, client);
 }
 
@@ -223,8 +226,8 @@ static void pres_task_resume(struct task_struct  *tsk)
         TRACE_TASK(tsk, "thread wakes up at %llu\n", litmus_clock());
 
         raw_spin_lock_irqsave(&state->lock, flags);
-        /* Requeue if self-suspension was already processed. */
-        if (state->scheduled != tsk)
+        /* Requeue only if self-suspension was already processed. */
+        if (tinfo->has_departed)
         {
                 /* Assumption: litmus_clock() is synchronized across cores,
                  * since we might not actually be executing on tinfo->cpu
@@ -234,8 +237,10 @@ static void pres_task_resume(struct task_struct  *tsk)
                 /* NOTE: drops state->lock */
                 pres_update_timer_and_unlock(state);
                 local_irq_restore(flags);
-        } else
+        } else {
+                TRACE_TASK(tsk, "resume event ignored, still scheduled\n");
                 raw_spin_unlock_irqrestore(&state->lock, flags);
+        }
 
         resume_legacy_task_model_updates(tsk);
 }
@@ -280,6 +285,7 @@ static long pres_admit_task(struct task_struct *tsk)
         if (res) {
                 task_client_init(&tinfo->res_info, tsk, res);
                 tinfo->cpu = task_cpu(tsk);
+                tinfo->has_departed = true;
                 tsk_rt(tsk)->plugin_state = tinfo;
                 err = 0;