Messages in this thread Patch in this message | | | From | Byungchul Park <> | Subject | [PATCH 6/8] sched/deadline: Don't return meaningless cpu in cpudl_maximum_cpu() | Date | Thu, 23 Mar 2017 19:32:41 +0900 |
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When the heap tree is empty, cp->elements[0].cpu has meaningless value. We need to consider the case.
Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- kernel/sched/cpudeadline.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index 37bbb66..21404b8 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -107,7 +107,8 @@ static void cpudl_heapify(struct cpudl_item *e, int size, int idx) static inline int cpudl_maximum_cpu(struct cpudl *cp) { - return cp->elements[0].cpu; + int cpu = cp->elements[0].cpu; + return cp->elements[cpu].idx == IDX_INVALID ? -1 : cpu; } static inline u64 cpudl_maximum_dl(struct cpudl *cp) @@ -127,7 +128,8 @@ static int cpudl_fast_find(struct cpudl *cp, struct task_struct *p) max_dl = cpudl_maximum_dl(cp); raw_spin_unlock_irqrestore(&cp->lock, flags); - if (cpumask_test_cpu(max_cpu, &p->cpus_allowed) && + if (max_cpu != -1 && + cpumask_test_cpu(max_cpu, &p->cpus_allowed) && dl_time_before(dl_se->deadline, max_dl)) return max_cpu; -- 1.9.1
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