From: Matthias Kruk <m@m10k.eu>
Date: Fri, 1 May 2020 01:39:36 +0000 (+0900)
Subject: sched/lazy: Fix bug in _lazy_tick() causing waiting processes to be scheduled
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=7b03940676f9111caff836c3b2da13d40d305af8;p=corax

sched/lazy: Fix bug in _lazy_tick() causing waiting processes to be scheduled
---

diff --git a/kernel/sched/lazy.c b/kernel/sched/lazy.c
index eed9823..fb7c7be 100644
--- a/kernel/sched/lazy.c
+++ b/kernel/sched/lazy.c
@@ -36,7 +36,16 @@ static int _lazy_tick(struct sched_lazy *lazy)
 			} else {
 				/* task has exhausted its time slice - reschedule */
 				ctask->t_rslice = ctask->t_tslice;
-				ctask->t_state = TASK_STATE_READY;
+
+				/*
+				 * This function will also be called with the intention to
+				 * reschedule, for example because the current task has changed
+				 * to TASK_STATE_WAITING. In such a case, we should not override
+				 * the task state here.
+				 */
+				if(ctask->t_state == TASK_STATE_RUNNING) {
+					ctask->t_state = TASK_STATE_READY;
+				}
 				ret_val = 1;
 			}
 		}