Hello!
At first glance, a WRITE_ONCE() in rcu_segcblist_set_flags() would cure
all these, but I thought I should double check. Thoughts?
Thanx, Paul
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_cb_kthread / rcu_nocb_gp_kthread
[34453.430323] read (marked) to 0xffff9dd1df26cb50 of 1 bytes by task 24 on cpu 13:
[34453.431069] rcu_nocb_cb_kthread+0x18b/0x760
[34453.431523] kthread+0x29b/0x2b0
[34453.431864] ret_from_fork+0x22/0x30
[34453.432245]
[34453.432418] no locks held by rcuop/1/24.
[34453.432823] irq event stamp: 13161844
[34453.433208] hardirqs last enabled at (13161844): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[34453.434220] hardirqs last disabled at (13161843): [<ffffffff9c71b053>] _raw_spin_lock_irqsave+0x53/0xb0
[34453.435129] softirqs last enabled at (13161839): [<ffffffff9b1ade6d>] local_bh_enable+0xd/0x30
[34453.435979] softirqs last disabled at (13161837): [<ffffffff9b1ad5dd>] local_bh_disable+0xd/0x30
[34453.436857]
[34453.437020] write to 0xffff9dd1df26cb50 of 1 bytes by task 15 on cpu 3:
[34453.437680] rcu_nocb_gp_kthread+0x3a3/0x1180
[34453.438137] kthread+0x29b/0x2b0
[34453.438482] ret_from_fork+0x22/0x30
[34453.438861]
[34453.439028] 1 lock held by rcuog/0/15:
[34453.439414] #0: ffff9dd1df26cc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_gp_kthread+0x2f2/0x1180
[34453.440382] irq event stamp: 22823959
[34453.440721] hardirqs last enabled at (22823958): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[34453.441892] hardirqs last disabled at (22823959): [<ffffffff9b1b1722>] rcu_nocb_gp_kthread+0x2d2/0x1180
[34453.442831] softirqs last enabled at (22823695): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[34453.443721] softirqs last disabled at (22823672): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
0xffffffff811b275b is in rcu_nocb_cb_kthread (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b17f3 is in rcu_nocb_gp_kthread (kernel/rcu/rcu_segcblist.h:59).
54 }
55
56 static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp,
57 int flags)
58 {
59 rsclp->flags |= flags;
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_core / rcu_nocb_cb_kthread
[35979.380848]
[35979.380999] read (marked) to 0xffff9dd1df5ecb50 of 1 bytes by interrupt on cpu 15:
[35979.381735] rcu_core+0x57/0x860
[35979.382058] rcu_core_si+0x12/0x20
[35979.382400] __do_softirq+0x1f9/0x37c
[35979.382749] run_ksoftirqd+0x4c/0x80
[35979.383097] smpboot_thread_fn+0x28b/0x390
[35979.383492] kthread+0x29b/0x2b0
[35979.383805] ret_from_fork+0x22/0x30
[35979.384149]
[35979.384298] no locks held by ksoftirqd/15/173.
[35979.384711] irq event stamp: 2431400
[35979.385049] hardirqs last enabled at (2431400): [<ffffffff9ca000de>] __do_softirq+0xde/0x37c
[35979.385841] hardirqs last disabled at (2431398): [<ffffffff9b0c060e>] run_ksoftirqd+0x2e/0x80
[35979.386631] softirqs last enabled at (2431394): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[35979.387429] softirqs last disabled at (2431399): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[35979.388215]
[35979.388364] write to 0xffff9dd1df5ecb50 of 1 bytes by task 176 on cpu 10:
[35979.388996] rcu_nocb_cb_kthread+0x479/0x760
[35979.389427] kthread+0x29b/0x2b0
[35979.389752] ret_from_fork+0x22/0x30
[35979.390106]
[35979.390260] 1 lock held by rcuop/15/176:
[35979.390634] #0: ffff9dd1df5ecc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_cb_kthread+0x2ff/0x760
0xffffffff811ad657 is in rcu_core (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b2a49 is in rcu_nocb_cb_kthread (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_cb_kthread / rcu_rdp_is_offloaded
[27570.512032] read (marked) to 0xffff9dd1df5ecb50 of 1 bytes by task 0 on cpu 15:
[27570.512770] rcu_rdp_is_offloaded+0x63/0x1c0
[27570.513222] rcu_needs_cpu+0x80/0xa0
[27570.513601] tick_nohz_next_event+0x1d4/0x300
[27570.514063] tick_nohz_idle_stop_tick+0x8f/0x3d0
[27570.514532] do_idle+0x108/0x2b0
[27570.514884] cpu_startup_entry+0x15/0x20
[27570.515301] secondary_startup_64_no_verify+0xc3/0xcb
[27570.515858]
[27570.515997] write to 0xffff9dd1df5ecb50 of 1 bytes by task 176 on cpu 0:
[27570.516577] rcu_nocb_cb_kthread+0x479/0x760
[27570.517358] kthread+0x29b/0x2b0
[27570.517712] ret_from_fork+0x22/0x30
[27570.518121]
[27570.518284] 1 lock held by rcuop/15/176:
[27570.518691] #0: ffff9dd1df5ecc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_cb_kthread+0x2ff/0x760
[27570.519677] irq event stamp: 20494903
[27570.520068] hardirqs last enabled at (20494902): [<ffffffff9b0bf40a>] __local_bh_enable_ip+0xca/0x120
[27570.536982] hardirqs last disabled at (20494903): [<ffffffff9b1b28b7>] rcu_nocb_cb_kthread+0x2e7/0x760
[27570.537913] softirqs last enabled at (20494901): [<ffffffff9b1ade6d>] local_bh_enable+0xd/0x30
[27570.538697] softirqs last disabled at (20494899): [<ffffffff9b1ad5dd>] local_bh_disable+0xd/0x30
rcu_rdp_is_offloaded+0x63
0xffffffff8119a543 is in rcu_rdp_is_offloaded (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b2a49 is in rcu_nocb_cb_kthread (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_gp_kthread / rcu_segcblist_ready_cbs
[22938.718032] read (marked) to 0xffff9dd1df5ecb50 of 1 bytes by interrupt on cpu 15:
[22938.718839] rcu_segcblist_ready_cbs+0x1a/0x40
[22938.719333] rcu_core+0x351/0x860
[22938.719703] rcu_core_si+0x12/0x20
[22938.720076] __do_softirq+0x1f9/0x37c
[22938.720470] run_ksoftirqd+0x4c/0x80
[22938.720879] smpboot_thread_fn+0x28b/0x390
[22938.721339] kthread+0x29b/0x2b0
[22938.721703] ret_from_fork+0x22/0x30
[22938.722089]
[22938.722252] no locks held by ksoftirqd/15/173.
[22938.722719] irq event stamp: 1553879
[22938.723104] hardirqs last enabled at (1553879): [<ffffffff9b1a7a8c>] note_gp_changes+0x1ac/0x1e0
[22938.723996] hardirqs last disabled at (1553878): [<ffffffff9b1a793b>] note_gp_changes+0x5b/0x1e0
[22938.724835] softirqs last enabled at (1553871): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[22938.736913] softirqs last disabled at (1553876): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[22938.737836]
[22938.738013] write to 0xffff9dd1df5ecb50 of 1 bytes by task 154 on cpu 10:
[22938.738725] rcu_nocb_gp_kthread+0x328/0x1180
[22938.739210] kthread+0x29b/0x2b0
[22938.739564] ret_from_fork+0x22/0x30
[22938.739963]
[22938.740141] 1 lock held by rcuog/12/154:
[22938.740578] #0: ffff9dd1df5ecc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_gp_kthread+0x2f2/0x1180
[22938.741584] irq event stamp: 19190924
[22938.741987] hardirqs last enabled at (19190923): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[22938.743018] hardirqs last disabled at (19190924): [<ffffffff9b1b1722>] rcu_nocb_gp_kthread+0x2d2/0x1180
[22938.743991] softirqs last enabled at (19189530): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[22938.744919] softirqs last disabled at (19189525): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
0xffffffff811b397a is in rcu_segcblist_ready_cbs (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b1778 is in rcu_nocb_gp_kthread (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_core / rcu_nocb_gp_kthread
[17703.531588] read (marked) to 0xffff9dd1df4ecb50 of 1 bytes by interrupt on cpu 11:
[17703.532349] rcu_segcblist_ready_cbs+0x1a/0x40
[17703.532801] rcu_core+0x351/0x860
[17703.533151] rcu_core_si+0x12/0x20
[17703.533515] __do_softirq+0x1f9/0x37c
[17703.533910] run_ksoftirqd+0x4c/0x80
[17703.534296] smpboot_thread_fn+0x28b/0x390
[17703.534741] kthread+0x29b/0x2b0
[17703.535111] ret_from_fork+0x22/0x30
[17703.535502]
[17703.535671] no locks held by ksoftirqd/11/143.
[17703.536162] irq event stamp: 1277315
[17703.536541] hardirqs last enabled at (1277315): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[17703.537604] hardirqs last disabled at (1277314): [<ffffffff9b1a793b>] note_gp_changes+0x5b/0x1e0
[17703.538666] softirqs last enabled at (1277307): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[17703.539560] softirqs last disabled at (1277312): [<ffffffff9b0c062c>] run_ksoftirqd+0x4c/0x80
[17703.540445]
[17703.540611] write to 0xffff9dd1df4ecb50 of 1 bytes by task 117 on cpu 0:
[17703.541320] rcu_nocb_gp_kthread+0x328/0x1180
[17703.541774] kthread+0x29b/0x2b0
[17703.542154] ret_from_fork+0x22/0x30
[17703.542544]
[17703.542712] 1 lock held by rcuog/8/117:
[17703.543126] #0: ffff9dd1df4ecc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_gp_kthread+0x2f2/0x1180
[17703.544068] irq event stamp: 14934462
[17703.544454] hardirqs last enabled at (14934461): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[17703.545469] hardirqs last disabled at (14934462): [<ffffffff9b1b1722>] rcu_nocb_gp_kthread+0x2d2/0x1180
[17703.546442] softirqs last enabled at (14934440): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[17703.547667] softirqs last disabled at (14934429): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
0xffffffff811b397a is in rcu_segcblist_ready_cbs (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b1778 is in rcu_nocb_gp_kthread (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_cb_kthread / rcu_nocb_rdp_deoffload
[25747.783445] read (marked) to 0xffff9dd1df5acb50 of 1 bytes by task 28476 on cpu 14:
[25747.784193] rcu_nocb_rdp_deoffload+0x1a3/0x380
[25747.784675] work_for_cpu_fn+0x32/0x50
[25747.785071] process_one_work+0x54f/0x840
[25747.785488] worker_thread+0x79c/0xa90
[25747.785884] kthread+0x29b/0x2b0
[25747.786230] ret_from_fork+0x22/0x30
[25747.786611]
[25747.786778] 2 locks held by kworker/14:2/28476:
[25747.787244] #0: ffff9dd1c1054738 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x4d7/0x840
[25747.788196] #1: ffffabe581ce3dd0 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x508/0x840
[25747.789216] irq event stamp: 47423
[25747.789563] hardirqs last enabled at (47423): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[25747.790533] hardirqs last disabled at (47422): [<ffffffff9c71b053>] _raw_spin_lock_irqsave+0x53/0xb0
[25747.791450] softirqs last enabled at (47410): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[25747.792253] softirqs last disabled at (47405): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[25747.804153]
[25747.804319] write to 0xffff9dd1df5acb50 of 1 bytes by task 169 on cpu 13:
[25747.805254] rcu_nocb_cb_kthread+0x479/0x760
[25747.805701] kthread+0x29b/0x2b0
[25747.806156] ret_from_fork+0x22/0x30
[25747.806581]
[25747.806747] 1 lock held by rcuop/14/169:
[25747.807344] #0: ffff9dd1df5acc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_cb_kthread+0x2ff/0x760
[25747.809333] irq event stamp: 19677863
[25747.810093] hardirqs last enabled at (19677862): [<ffffffff9b0bf40a>] __local_bh_enable_ip+0xca/0x120
[25747.820095] hardirqs last disabled at (19677863): [<ffffffff9b1b28b7>] rcu_nocb_cb_kthread+0x2e7/0x760
[25747.822317] softirqs last enabled at (19677861): [<ffffffff9b1ade6d>] local_bh_enable+0xd/0x30
[25747.824060] softirqs last disabled at (19677859): [<ffffffff9b1ad5dd>] local_bh_disable+0xd/0x30
0xffffffff811a5853 is in rcu_nocb_rdp_deoffload (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b2a49 is in rcu_nocb_cb_kthread (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_gp_kthread / rcu_nocb_rdp_offload
[15688.905747] read (marked) to 0xffff9dd1df56cb50 of 1 bytes by task 154 on cpu 9:
[15688.906550] rcu_nocb_gp_kthread+0x237/0x1180
[15688.907050] kthread+0x29b/0x2b0
[15688.907421] ret_from_fork+0x22/0x30
[15688.907824]
[15688.908022] no locks held by rcuog/12/154.
[15688.908468] irq event stamp: 13085451
[15688.908865] hardirqs last enabled at (13085451): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[15688.909929] hardirqs last disabled at (13085450): [<ffffffff9c71b053>] _raw_spin_lock_irqsave+0x53/0xb0
[15688.910949] softirqs last enabled at (13085112): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[15688.911908] softirqs last disabled at (13085107): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[15688.912849]
[15688.913043] write to 0xffff9dd1df56cb50 of 1 bytes by task 16476 on cpu 13:
[15688.913830] rcu_nocb_rdp_offload+0x24e/0x2c0
[15688.914364] work_for_cpu_fn+0x32/0x50
[15688.914805] process_one_work+0x54f/0x840
[15688.915159] worker_thread+0x79c/0xa90
[15688.915544] kthread+0x29b/0x2b0
[15688.915907] ret_from_fork+0x22/0x30
[15688.916325]
[15688.916502] 3 locks held by kworker/13:0/16476:
[15688.917016] #0: ffff9dd1c1054738 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x4d7/0x840
[15688.918073] #1: ffffabe585163dd0 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: process_one_work+0x508/0x840
[15688.919153] #2: ffff9dd1df56cc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_rdp_offload+0x237/0x2c0
[15688.920171] irq event stamp: 198553
[15688.920539] hardirqs last enabled at (198552): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[15688.921577] hardirqs last disabled at (198553): [<ffffffff9b1a5d5e>] rcu_nocb_rdp_offload+0x21e/0x2c0
[15688.922553] softirqs last enabled at (198341): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[15688.923462] softirqs last disabled at (198336): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
0xffffffff811b1687 is in rcu_nocb_gp_kthread (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811a5d8e is in rcu_nocb_rdp_offload (kernel/rcu/rcu_segcblist.h:65).
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
64 {
65 rsclp->flags &= ~flags;
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
------------------------------------------------------------------------
BUG: KCSAN: data-race in rcu_nocb_gp_kthread / rcu_rdp_is_offloaded
[30067.322599] read (marked) to 0xffff9dd1df2ecb50 of 1 bytes by interrupt on cpu 3:
[30067.323367] rcu_rdp_is_offloaded+0x63/0x1c0
[30067.323929] rcu_sched_clock_irq+0x9d2/0x18d0
[30067.324269] update_process_times+0xe9/0x110
[30067.324692] tick_sched_timer+0xfd/0x170
[30067.325195] __hrtimer_run_queues+0x28a/0x450
[30067.325647] hrtimer_interrupt+0x234/0x6d0
[30067.326519] __sysvec_apic_timer_interrupt+0xb8/0x1a0
[30067.327039] sysvec_apic_timer_interrupt+0x9a/0xc0
[30067.327557] asm_sysvec_apic_timer_interrupt+0x12/0x20
[30067.328105] __tsan_read8+0x167/0x240
[30067.328503] rcutorture_one_extend+0x211/0x590
[30067.328994] rcu_torture_one_read+0x785/0xc90
[30067.329444] rcu_torture_reader+0x19b/0x2e0
[30067.330309] kthread+0x29b/0x2b0
[30067.330654] ret_from_fork+0x22/0x30
[30067.331075]
[30067.331240] 2 locks held by rcu_torture_rea/93:
[30067.331700] #0: ffffffff9d35c208 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire+0x11/0x40
[30067.332708] #1: ffffffff9d35c238 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x11/0x40
[30067.333656] irq event stamp: 2508045894
[30067.334185] hardirqs last enabled at (2508045893): [<ffffffff9b0bf40a>] __local_bh_enable_ip+0xca/0x120
[30067.335192] hardirqs last disabled at (2508045894): [<ffffffff9c70e1f7>] sysvec_apic_timer_interrupt+0x17/0xc0
[30067.342726] softirqs last enabled at (2508045892): [<ffffffff9b1956fd>] local_bh_enable+0xd/0x30
[30067.354637] softirqs last disabled at (2508045890): [<ffffffff9b1956cd>] local_bh_disable+0xd/0x30
[30067.355483]
[30067.355627] write to 0xffff9dd1df2ecb50 of 1 bytes by task 15 on cpu 0:
[30067.356228] rcu_nocb_gp_kthread+0x3a3/0x1180
[30067.356628] kthread+0x29b/0x2b0
[30067.356936] ret_from_fork+0x22/0x30
[30067.357284]
[30067.357431] 1 lock held by rcuog/0/15:
[30067.357873] #0: ffff9dd1df2ecc70 (&rdp->nocb_lock){-.-.}-{2:2}, at: rcu_nocb_gp_kthread+0x2f2/0x1180
[30067.358746] irq event stamp: 19891260
[30067.359093] hardirqs last enabled at (19891259): [<ffffffff9c71b23a>] _raw_spin_unlock_irqrestore+0x3a/0x70
[30067.359998] hardirqs last disabled at (19891260): [<ffffffff9b1b1722>] rcu_nocb_gp_kthread+0x2d2/0x1180
[30067.360860] softirqs last enabled at (19890706): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
[30067.361694] softirqs last disabled at (19890697): [<ffffffff9b0bf844>] __irq_exit_rcu+0x64/0xc0
0xffffffff8119a543 is in rcu_rdp_is_offloaded (kernel/rcu/rcu_segcblist.h:71).
66 }
67
68 static inline bool rcu_segcblist_test_flags(struct rcu_segcblist *rsclp,
69 int flags)
70 {
71 return READ_ONCE(rsclp->flags) & flags;
72 }
73
74 /*
75 * Is the specified rcu_segcblist enabled, for example, not corresponding
0xffffffff811b17f3 is in rcu_nocb_gp_kthread (kernel/rcu/rcu_segcblist.h:59).
54 }
55
56 static inline void rcu_segcblist_set_flags(struct rcu_segcblist *rsclp,
57 int flags)
58 {
59 rsclp->flags |= flags;
60 }
61
62 static inline void rcu_segcblist_clear_flags(struct rcu_segcblist *rsclp,
63 int flags)
