From b9dca1e0fcb696716840a3bc8f20a6941b484dbf Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Wed, 17 Oct 2007 16:55:11 +0200 Subject: [PATCH] sched: fix new task startup crash Child task may be added on a different cpu that the one on which parent is running. In which case, task_new_fair() should check whether the new born task's parent entity should be added as well on the cfs_rq. Patch below fixes the problem in task_new_fair. This could fix the put_prev_task_fair() crashes reported. Reported-by: Kamalesh Babulal Reported-by: Andy Whitcroft Signed-off-by: Srivatsa Vaddagiri Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- kernel/sched_fair.c | 6 +----- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index 975436435b42..0ec9521a8e70 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1712,7 +1712,7 @@ void fastcall wake_up_new_task(struct task_struct *p, unsigned long clone_flags) p->prio = effective_prio(p); - if (!p->sched_class->task_new || !current->se.on_rq || !rq->cfs.curr) { + if (!p->sched_class->task_new || !current->se.on_rq) { activate_task(rq, p, 0); } else { /* diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a17b785d7000..166ed6db600b 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1031,12 +1031,8 @@ static void task_new_fair(struct rq *rq, struct task_struct *p) swap(curr->vruntime, se->vruntime); } - update_stats_enqueue(cfs_rq, se); - check_spread(cfs_rq, se); - check_spread(cfs_rq, curr); - __enqueue_entity(cfs_rq, se); - account_entity_enqueue(cfs_rq, se); se->peer_preempt = 0; + enqueue_task_fair(rq, p, 0); resched_task(rq->curr); } -- 2.20.1