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| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-18 09:53:59 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-18 09:53:59 -0700 |
| commit | 2c11fc87caa9a60ada54f4bfc97f7b1abc38d7d0 (patch) | |
| tree | 50a0899747507dd45861687cc58793ecc40d3734 /kernel | |
| parent | Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff) | |
| parent | sched/fair: Fix sched domains NULL dereference in select_idle_sibling() (diff) | |
| download | linux-dev-2c11fc87caa9a60ada54f4bfc97f7b1abc38d7d0.tar.xz linux-dev-2c11fc87caa9a60ada54f4bfc97f7b1abc38d7d0.zip | |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
"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()"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Fix sched domains NULL dereference in select_idle_sibling()
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 2d4ad72f8f3c..76ee7de1859d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -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. |