From 094f469172e00d6ab0a3130b0e01c83b3cf3a98d Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Thu, 16 Jun 2016 15:57:01 +0300 Subject: sched/fair: Initialize throttle_count for new task-groups lazily Cgroup created inside throttled group must inherit current throttle_count. Broken throttle_count allows to nominate throttled entries as a next buddy, later this leads to null pointer dereference in pick_next_task_fair(). This patch initialize cfs_rq->throttle_count at first enqueue: laziness allows to skip locking all rq at group creation. Lazy approach also allows to skip full sub-tree scan at throttling hierarchy (not in this patch). Signed-off-by: Konstantin Khlebnikov Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: bsegall@google.com Link: http://lkml.kernel.org/r/146608182119.21870.8439834428248129633.stgit@buzz Signed-off-by: Ingo Molnar --- kernel/sched/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sched/sched.h') diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 72f1f30..7cbeb92 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -437,7 +437,7 @@ struct cfs_rq { u64 throttled_clock, throttled_clock_task; u64 throttled_clock_task_time; - int throttled, throttle_count; + int throttled, throttle_count, throttle_uptodate; struct list_head throttled_list; #endif /* CONFIG_CFS_BANDWIDTH */ #endif /* CONFIG_FAIR_GROUP_SCHED */ -- cgit v1.1