FYI, we noticed the below changes on
commit eeb61e53ea19be0c4015b00b2e8b3b2185436f2b ("sched: Fix race between task_group and sched_task_group")
+---------------------------+------------+------------+
| | xfs-for-li | eeb61e53ea |
+---------------------------+------------+------------+
| boot_successes | 0 | 0 |
| boot_failures | 54 | 10 |
| BUG:kernel_boot_hang | 54 | 10 |
| INFO:suspicious_RCU_usage | 0 | 10 |
| backtrace:do_fork | 0 | 10 |
+---------------------------+------------+------------+
[ 0.054010] ftrace: allocating 44163 entries in 87 pages
[ 0.072399]
[ 0.073480] ===============================
[ 0.074916] [ INFO: suspicious RCU usage. ]
[ 0.076000] 3.18.0-rc2-g05da589 #861 Not tainted
[ 0.076000] -------------------------------
[ 0.076000] kernel/sched/core.c:7449 suspicious rcu_dereference_check() usage!
[ 0.076000]
[ 0.076000] other info that might help us debug this:
[ 0.076000]
[ 0.076000]
[ 0.076000] rcu_scheduler_active = 1, debug_locks = 0
[ 0.076000] 2 locks held by swapper/0/0:
[ 0.076000] #0: (&p->pi_lock){......}, at: [<c1069318>] task_rq_lock+0x28/0xba
[ 0.076000] #1: (&rq->lock){-.....}, at: [<c1069336>] task_rq_lock+0x46/0xba
[ 0.076000]
[ 0.076000] stack backtrace:
[ 0.076000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.18.0-rc2-g05da589 #861
[ 0.076000] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 0.076000] 00000000 00000000 c209be98 c1b238b0 00000001 c209beb4 c108ba6a c1f54e96
[ 0.076000] c20a3550 d30c0000 d370c300 c20b28a0 c209bed4 c10731b6 00000000 00003550
[ 0.076000] 00200246 d30c0000 00000000 00000000 c209bedc c1073285 c209bef0 c10cb273
[ 0.076000] Call Trace:
[ 0.076000] [<c1b238b0>] dump_stack+0x48/0x60
[ 0.076000] [<c108ba6a>] lockdep_rcu_suspicious+0xd3/0xdc
[ 0.076000] [<c10731b6>] sched_move_task+0xd1/0x17c
[ 0.076000] [<c1073285>] cpu_cgroup_fork+0xd/0xf
[ 0.076000] [<c10cb273>] cgroup_post_fork+0xe1/0xec
[ 0.076000] [<c10464a4>] copy_process+0x1652/0x181f
[ 0.076000] [<c1b1c321>] ? rest_init+0x116/0x116
[ 0.076000] [<c1073f5b>] ? sched_clock_cpu+0x11b/0x136
[ 0.076000] [<c1b1c321>] ? rest_init+0x116/0x116
[ 0.076000] [<c10467c7>] do_fork+0x7d/0x632
[ 0.076000] [<c1088ad7>] ? trace_hardirqs_on_caller+0x160/0x17b
[ 0.076000] [<c1b1c321>] ? rest_init+0x116/0x116
[ 0.076000] [<c1088afd>] ? trace_hardirqs_on+0xb/0xd
[ 0.076000] [<c106ce9c>] ? nr_context_switches+0xb2/0xe4
[ 0.076000] [<c1b1c321>] ? rest_init+0x116/0x116
[ 0.076000] [<c1046d9b>] kernel_thread+0x1f/0x24
[ 0.076000] [<c1b1c22a>] rest_init+0x1f/0x116
[ 0.076000] [<c222db5b>] start_kernel+0x3fd/0x404
[ 0.076000] [<c222d2af>] i386_start_kernel+0x79/0x7d
[ 0.076113] Getting VERSION: 50014
[ 0.077525] Getting VERSION: 50014
[ 0.080016] Getting ID: 0
--yliu