scheduler fix
Linus,
Please pull the latest sched-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus
# HEAD: 9cfb38a7ba5a9c27c1af8093fb1af4b699c0a441 sched/fair: Fix sched domains NULL dereference in select_idle_sibling()
Fix a crash that can trigger when racing with CPU hotplug: we didn't use sched-domains data structures carefully enough in select_idle_cpu().
Thanks,
Ingo
------------------>
Wanpeng Li (1):
sched/fair: Fix sched domains NULL dereference in select_idle_sibling()
kernel/sched/fair.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
kernel/sched/fair.c +8 -3
@@ -5471,13 +5471,18 @@ static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd*/ static int select_idle_cpu (struct task_struct *p,struct sched_domain *sd,int target) { -struct sched_domain *this_sd =rcu_dereference (*this_cpu_ptr (&sd_llc)); -u64 avg_idle =this_rq ()->avg_idle; -u64 avg_cost = this_sd->avg_scan_cost; +struct sched_domain *this_sd; +u64 avg_cost, avg_idle =this_rq ()->avg_idle;u64 time, cost;s64 delta;int cpu, wrap; + this_sd =rcu_dereference (*this_cpu_ptr (&sd_llc)); +if (!this_sd) +return -1 ; + + avg_cost = this_sd->avg_scan_cost; +/* * Due to large variance we need a large fuzz factor; hackbench in * particularly is sensitive here.