linux/kernel/sched
Tetsuo Handa 7f1a169b88 sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group()
When alloc_fair_sched_group() in sched_create_group() fails,
free_sched_group() is called, and free_fair_sched_group() is called by
free_sched_group(). Since destroy_cfs_bandwidth() is called by
free_fair_sched_group() without calling init_cfs_bandwidth(),
RCU stall occurs at hrtimer_cancel():

  INFO: rcu_sched self-detected stall on CPU { 1}  (t=60000 jiffies g=13074 c=13073 q=0)
  Task dump for CPU 1:
  (fprintd)       R  running task        0  6249      1 0x00000088
  ...
  Call Trace:
   <IRQ>  [<ffffffff81094988>] sched_show_task+0xa8/0x110
   [<ffffffff81097acd>] dump_cpu_task+0x3d/0x50
   [<ffffffff810c3a80>] rcu_dump_cpu_stacks+0x90/0xd0
   [<ffffffff810c7751>] rcu_check_callbacks+0x491/0x700
   [<ffffffff810cbf2b>] update_process_times+0x4b/0x80
   [<ffffffff810db046>] tick_sched_handle.isra.20+0x36/0x50
   [<ffffffff810db0a2>] tick_sched_timer+0x42/0x70
   [<ffffffff810ccb19>] __run_hrtimer+0x69/0x1a0
   [<ffffffff810db060>] ? tick_sched_handle.isra.20+0x50/0x50
   [<ffffffff810ccedf>] hrtimer_interrupt+0xef/0x230
   [<ffffffff810452cb>] local_apic_timer_interrupt+0x3b/0x70
   [<ffffffff8164a465>] smp_apic_timer_interrupt+0x45/0x60
   [<ffffffff816485bd>] apic_timer_interrupt+0x6d/0x80
   <EOI>  [<ffffffff810cc588>] ? lock_hrtimer_base.isra.23+0x18/0x50
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810cc9d2>] hrtimer_try_to_cancel+0x22/0xd0
   [<ffffffff81193cf1>] ? __kmalloc+0x211/0x230
   [<ffffffff810ccaa2>] hrtimer_cancel+0x22/0x30
   [<ffffffff810a3cb5>] free_fair_sched_group+0x25/0xd0
   [<ffffffff8108df46>] free_sched_group+0x16/0x40
   [<ffffffff810971bb>] sched_create_group+0x4b/0x80
   [<ffffffff810aa383>] sched_autogroup_create_attach+0x43/0x1c0
   [<ffffffff8107dc9c>] sys_setsid+0x7c/0x110
   [<ffffffff81647729>] system_call_fastpath+0x12/0x17

Check whether init_cfs_bandwidth() was called before calling
destroy_cfs_bandwidth().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
[ Move the check into destroy_cfs_bandwidth() to aid compilability. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/201412252210.GCC30204.SOMVFFOtQJFLOH@I-love.SAKURA.ne.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-09 11:19:00 +01:00
..
auto_group.c sched: Change autogroup_move_group() to use for_each_thread() 2014-08-20 09:47:18 +02:00
auto_group.h Revert "sched/autogroup: Fix crash on reboot when autogroup is disabled" 2012-12-11 10:23:45 +01:00
clock.c time: Replace __get_cpu_var uses 2014-08-26 13:45:44 -04:00
completion.c sched/completion: Document when to use wait_for_completion_io_*() 2014-11-16 10:58:54 +01:00
core.c sched: Fix KMALLOC_MAX_SIZE overflow during cpumask allocation 2014-12-23 11:43:48 +01:00
cpuacct.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
cpuacct.h sched/cpuacct: Initialize root cpuacct earlier 2013-04-10 13:54:20 +02:00
cpudeadline.c sched/deadline: Fix inter- exclusive cpusets migrations 2014-09-24 14:46:57 +02:00
cpudeadline.h sched/deadline: Remove unnecessary definitions in cpudeadline.h 2014-11-16 10:59:00 +01:00
cpupri.c Merge commit '3cf2f34' into sched/core, to fix build error 2014-06-12 13:46:37 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched, time: Fix build error with 64 bit cputime_t on 32 bit systems 2014-10-03 05:46:55 +02:00
deadline.c sched/deadline: Avoid double-accounting in case of missed deadlines 2015-01-09 11:18:57 +01:00
debug.c sched: Refactor task_struct to use numa_faults instead of numa_* pointers 2014-11-04 07:17:57 +01:00
fair.c sched/fair: Fix RCU stall upon -ENOMEM in sched_create_group() 2015-01-09 11:19:00 +01:00
features.h sched: Rename capacity related flags 2014-06-05 11:52:32 +02:00
idle_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
idle.c sched: Let the scheduler see CPU idle states 2014-09-24 14:46:58 +02:00
Makefile sched/idle: Move cpu/idle.c to sched/idle.c 2014-02-11 09:58:30 +01:00
proc.c cpuidle: menu: Lookup CPU runqueues less 2014-08-06 21:17:45 +02:00
rt.c sched: Move p->nr_cpus_allowed check to select_task_rq() 2014-11-16 10:58:55 +01:00
sched.h Merge branch 'sched/urgent' into sched/core, to pick up fixes before applying more changes 2014-11-16 10:50:25 +01:00
stats.c kernel: audit/fix non-modular users of module_init in core code 2014-04-03 16:21:07 -07:00
stats.h sched: Micro-optimize by dropping unnecessary task_rq() calls 2013-09-25 13:51:06 +02:00
stop_task.c sched: Provide update_curr callbacks for stop/idle scheduling classes 2014-11-23 14:14:40 -08:00
wait.c sched/wait: Fix a kthread race with wait_woken() 2014-11-04 07:17:44 +01:00