sched/eevdf: Fixup PELT vs DELAYED_DEQUEUE

Note that tasks that are kept on the runqueue to burn off negative
lag, are not in fact runnable anymore, they'll get dequeued the moment
they get picked.

As such, don't count this time towards runnable.

Thanks to Valentin for spotting I had this backwards initially.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Tested-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lkml.kernel.org/r/20240727105030.514088302@infradead.org

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1a593393e3088d835b9a81827f75e634219e497f..0eb1bbf7f269771b670580d08d546d44ebce8f19 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5402,6 +5402,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
                    !entity_eligible(cfs_rq, se)) {
                        if (cfs_rq->next == se)
                                cfs_rq->next = NULL;
+                       update_load_avg(cfs_rq, se, 0);
                        se->sched_delayed = 1;
                        return false;
                }
@@ -6841,6 +6842,7 @@ requeue_delayed_entity(struct sched_entity *se)
                }
        }
 
+       update_load_avg(cfs_rq, se, 0);
        se->sched_delayed = 0;
 }
 

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 263b4ded2b47d5dc13ee740f7f513feac3934ee8..2f5d658c0631fc8cc7993a7e6a35aa8b086e68d7 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -820,6 +820,9 @@ static inline void se_update_runnable(struct sched_entity *se)
 
 static inline long se_runnable(struct sched_entity *se)
 {
+       if (se->sched_delayed)
+               return false;
+
        if (entity_is_task(se))
                return !!se->on_rq;
        else
@@ -834,6 +837,9 @@ static inline void se_update_runnable(struct sched_entity *se) { }
 
 static inline long se_runnable(struct sched_entity *se)
 {
+       if (se->sched_delayed)
+               return false;
+
        return !!se->on_rq;
 }