Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
Merge tag 'sched-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Two EEVDF fixes"
* tag 'sched-urgent-2023-10-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/eevdf: Fix pick_eevdf()
sched/eevdf: Fix min_deadline heap integrity
+59
-14
+59
-14
kernel/sched/fair.c
+59
-14
kernel/sched/fair.c
···
872
872
*
873
873
* Which allows an EDF like search on (sub)trees.
874
874
*/
875
-
static struct sched_entity *pick_eevdf(struct cfs_rq *cfs_rq)
875
+
static struct sched_entity *__pick_eevdf(struct cfs_rq *cfs_rq)
876
876
{
877
877
struct rb_node *node = cfs_rq->tasks_timeline.rb_root.rb_node;
878
878
struct sched_entity *curr = cfs_rq->curr;
879
879
struct sched_entity *best = NULL;
880
+
struct sched_entity *best_left = NULL;
880
881
881
882
if (curr && (!curr->on_rq || !entity_eligible(cfs_rq, curr)))
882
883
curr = NULL;
884
+
best = curr;
883
885
884
886
/*
885
887
* Once selected, run a task until it either becomes non-eligible or
···
902
900
}
903
901
904
902
/*
905
-
* If this entity has an earlier deadline than the previous
906
-
* best, take this one. If it also has the earliest deadline
907
-
* of its subtree, we're done.
903
+
* Now we heap search eligible trees for the best (min_)deadline
908
904
*/
909
-
if (!best || deadline_gt(deadline, best, se)) {
905
+
if (!best || deadline_gt(deadline, best, se))
910
906
best = se;
911
-
if (best->deadline == best->min_deadline)
907
+
908
+
/*
909
+
* Every se in a left branch is eligible, keep track of the
910
+
* branch with the best min_deadline
911
+
*/
912
+
if (node->rb_left) {
913
+
struct sched_entity *left = __node_2_se(node->rb_left);
914
+
915
+
if (!best_left || deadline_gt(min_deadline, best_left, left))
916
+
best_left = left;
917
+
918
+
/*
919
+
* min_deadline is in the left branch. rb_left and all
920
+
* descendants are eligible, so immediately switch to the second
921
+
* loop.
922
+
*/
923
+
if (left->min_deadline == se->min_deadline)
912
924
break;
913
925
}
914
926
915
-
/*
916
-
* If the earlest deadline in this subtree is in the fully
917
-
* eligible left half of our space, go there.
918
-
*/
927
+
/* min_deadline is at this node, no need to look right */
928
+
if (se->deadline == se->min_deadline)
929
+
break;
930
+
931
+
/* else min_deadline is in the right branch. */
932
+
node = node->rb_right;
933
+
}
934
+
935
+
/*
936
+
* We ran into an eligible node which is itself the best.
937
+
* (Or nr_running == 0 and both are NULL)
938
+
*/
939
+
if (!best_left || (s64)(best_left->min_deadline - best->deadline) > 0)
940
+
return best;
941
+
942
+
/*
943
+
* Now best_left and all of its children are eligible, and we are just
944
+
* looking for deadline == min_deadline
945
+
*/
946
+
node = &best_left->run_node;
947
+
while (node) {
948
+
struct sched_entity *se = __node_2_se(node);
949
+
950
+
/* min_deadline is the current node */
951
+
if (se->deadline == se->min_deadline)
952
+
return se;
953
+
954
+
/* min_deadline is in the left branch */
919
955
if (node->rb_left &&
920
956
__node_2_se(node->rb_left)->min_deadline == se->min_deadline) {
921
957
node = node->rb_left;
922
958
continue;
923
959
}
924
960
961
+
/* else min_deadline is in the right branch */
925
962
node = node->rb_right;
926
963
}
964
+
return NULL;
965
+
}
927
966
928
-
if (!best || (curr && deadline_gt(deadline, best, curr)))
929
-
best = curr;
967
+
static struct sched_entity *pick_eevdf(struct cfs_rq *cfs_rq)
968
+
{
969
+
struct sched_entity *se = __pick_eevdf(cfs_rq);
930
970
931
-
if (unlikely(!best)) {
971
+
if (!se) {
932
972
struct sched_entity *left = __pick_first_entity(cfs_rq);
933
973
if (left) {
934
974
pr_err("EEVDF scheduling fail, picking leftmost\n");
···
978
934
}
979
935
}
980
936
981
-
return best;
937
+
return se;
982
938
}
983
939
984
940
#ifdef CONFIG_SCHED_DEBUG
···
3657
3613
*/
3658
3614
deadline = div_s64(deadline * old_weight, weight);
3659
3615
se->deadline = se->vruntime + deadline;
3616
+
min_deadline_cb_propagate(&se->run_node, NULL);
3660
3617
}
3661
3618
3662
3619
#ifdef CONFIG_SMP