Re: [PATCH v4 11/19] sched/core: Make migrate disable and CPU hotplug cooperative
From: Qian Cai
Date: Fri Nov 13 2020 - 10:07:06 EST
On Fri, 2020-10-23 at 12:12 +0200, Peter Zijlstra wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> On CPU unplug tasks which are in a migrate disabled region cannot be pushed
> to a different CPU until they returned to migrateable state.
>
> Account the number of tasks on a runqueue which are in a migrate disabled
> section and make the hotplug wait mechanism respect that.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
> kernel/sched/core.c | 36 ++++++++++++++++++++++++++++++------
> kernel/sched/sched.h | 4 ++++
> 2 files changed, 34 insertions(+), 6 deletions(-)
>
[]
> @@ -7310,7 +7334,7 @@ int sched_cpu_dying(unsigned int cpu)
> sched_tick_stop(cpu);
>
> rq_lock_irqsave(rq, &rf);
> - BUG_ON(rq->nr_running != 1);
> + BUG_ON(rq->nr_running != 1 || rq_has_pinned_tasks(rq));
CPU hotplug is now triggering this. This is with Valentin's affine_move_task()
fix on top:
https://lore.kernel.org/lkml/20201113112414.2569-1-valentin.schneider@xxxxxxx/
[ 809.412232][ T428] kernel BUG at kernel/sched/core.c:7547!
[ 809.417841][ T428] invalid opcode: 0000 [#1] SMP KASAN PTI
[ 809.423445][ T428] CPU: 72 PID: 428 Comm: migration/72 Tainted: G I 5.10.0-rc3-next-20201113+ #1
[ 809.433678][ T428] Hardware name: HPE ProLiant DL560 Gen10/ProLiant DL560 Gen10, BIOS U34 11/13/2019
[ 809.442951][ T428] Stopper: multi_cpu_stop+0x0/0x350 <- 0x0
[ 809.448643][ T428] RIP: 0010:sched_cpu_dying+0x10f/0x130
[ 809.454071][ T428] Code: 10 00 31 c0 48 83 c4 08 5b 41 5c 41 5d 5d c3 be 08 00 00 00 48 c7 c7 60 3f b5 96 e8 ab 81 4d 00 f0 4c 01 25 73 c4 5a 09 eb a3 <0f> 0b 48 89 34 24 e8 86 7d 4d 00 48 8b 34 24 e9 5d ff ff ff e8 88
[ 809.473650][ T428] RSP: 0018:ffffc9000889fca0 EFLAGS: 00010002
[ 809.479606][ T428] RAX: 0000000000000000 RBX: ffff8887dfcb23c0 RCX: ffffffff8e057e0d
[ 809.487482][ T428] RDX: 1ffff110fbf96480 RSI: 0000000000007c11 RDI: ffff8887dfcb2400
[ 809.495355][ T428] RBP: ffffc9000889fcc0 R08: fffffbfff2cb8e96 R09: fffffbfff2cb8e96
[ 809.503229][ T428] R10: ffffffff965c74af R11: fffffbfff2cb8e95 R12: ffff8887dfcb23d8
[ 809.511103][ T428] R13: 0000000000000086 R14: ffffffff8d5038e0 R15: 0000000000000003
[ 809.518979][ T428] FS: 0000000000000000(0000) GS:ffff8887dfc80000(0000) knlGS:0000000000000000
[ 809.527815][ T428] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 809.534291][ T428] CR2: 00007fea4cdf899c CR3: 00000018c7414002 CR4: 00000000007706e0
[ 809.542165][ T428] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 809.550040][ T428] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 809.557913][ T428] PKRU: 55555554
[ 809.561332][ T428] Call Trace:
[ 809.564489][ T428] ? x86_pmu_starting_cpu+0x20/0x20
[ 809.569570][ T428] ? sched_cpu_wait_empty+0x220/0x220
[ 809.574826][ T428] cpuhp_invoke_callback+0x1d8/0x1520
[ 809.580082][ T428] ? x2apic_send_IPI_mask+0x10/0x10
[ 809.585161][ T428] ? clear_local_APIC+0x788/0xc10
[ 809.590068][ T428] ? cpuhp_invoke_callback+0x1520/0x1520
[ 809.595584][ T428] take_cpu_down+0x10f/0x1a0
[ 809.600053][ T428] multi_cpu_stop+0x149/0x350
[ 809.604607][ T428] ? stop_machine_yield+0x10/0x10
[ 809.609511][ T428] cpu_stopper_thread+0x200/0x400
[ 809.614416][ T428] ? cpu_stop_create+0x70/0x70
[ 809.619059][ T428] smpboot_thread_fn+0x30a/0x770
[ 809.623878][ T428] ? smpboot_register_percpu_thread+0x370/0x370
[ 809.630005][ T428] ? trace_hardirqs_on+0x1c/0x150
[ 809.634910][ T428] ? __kthread_parkme+0xcc/0x1a0
[ 809.639729][ T428] ? smpboot_register_percpu_thread+0x370/0x370
[ 809.645855][ T428] kthread+0x352/0x420
[ 809.649798][ T428] ? kthread_create_on_node+0xc0/0xc0
[ 809.655052][ T428] ret_from_fork+0x22/0x30
[ 809.659345][ T428] Modules linked in: nls_ascii nls_cp437 vfat fat kvm_intel kvm ses enclosure irqbypass efivarfs ip_tables x_tables sd_mod nvme tg3 firmware_class smartpqi nvme_core scsi_transport_sas libphy dm_mirror dm_region_hash dm_log dm_mod
[ 809.681502][ T428] ---[ end trace 416318a3e677bf17 ]---
[ 809.686844][ T428] RIP: 0010:sched_cpu_dying+0x10f/0x130
[ 809.692273][ T428] Code: 10 00 31 c0 48 83 c4 08 5b 41 5c 41 5d 5d c3 be 08 00 00 00 48 c7 c7 60 3f b5 96 e8 ab 81 4d 00 f0 4c 01 25 73 c4 5a 09 eb a3 <0f> 0b 48 89 34 24 e8 86 7d 4d 00 48 8b 34 24 e9 5d ff ff ff e8 88
[ 809.711853][ T428] RSP: 0018:ffffc9000889fca0 EFLAGS: 00010002
[ 809.717807][ T428] RAX: 0000000000000000 RBX: ffff8887dfcb23c0 RCX: ffffffff8e057e0d
[ 809.725681][ T428] RDX: 1ffff110fbf96480 RSI: 0000000000007c11 RDI: ffff8887dfcb2400
[ 809.733556][ T428] RBP: ffffc9000889fcc0 R08: fffffbfff2cb8e96 R09: fffffbfff2cb8e96
[ 809.741432][ T428] R10: ffffffff965c74af R11: fffffbfff2cb8e95 R12: ffff8887dfcb23d8
[ 809.749307][ T428] R13: 0000000000000086 R14: ffffffff8d5038e0 R15: 0000000000000003
[ 809.757182][ T428] FS: 0000000000000000(0000) GS:ffff8887dfc80000(0000) knlGS:0000000000000000
[ 809.766018][ T428] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 809.772495][ T428] CR2: 00007fea4cdf899c CR3: 00000018c7414002 CR4: 00000000007706e0
[ 809.780369][ T428] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 809.788242][ T428] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 809.796118][ T428] PKRU: 55555554
[ 809.799538][ T428] Kernel panic - not syncing: Fatal exception
[ 809.805543][ T428]
[ 809.805544][ T428] unchecked MSR access error: WRMSR to 0x83f (tried to write 0x00000000000000f6) at rIP: 0xffffffff8d4c8a43 (native_apic_msr_write+0x23/0x40)
[ 809.805545][ T428] Call Trace:
[ 809.805546][ T428] arch_irq_work_raise+0x9b/0x110
[ 809.805547][ T428] irq_work_queue+0x24/0x40
[ 809.805548][ T428] printk_safe_log_store+0x185/0x1b0
[ 809.805549][ T428] ? kmsg_dump_rewind_nolock+0x80/0x80
[ 809.805549][ T428] ? ret_from_fork+0x22/0x30
[ 809.805550][ T428] printk+0x9a/0xc0
[ 809.805551][ T428] ? record_print_text.cold.38+0x11/0x11
[ 809.805552][ T428] ? stack_trace_consume_entry+0x160/0x160
[ 809.805553][ T428] ? save_trace+0x3d/0xb40
[ 809.805554][ T428] print_circular_bug_header.cold.69+0x10/0xd7
[ 809.805556][ T428] print_circular_bug.isra.42+0x1ac/0x300
[ 809.805557][ T428] check_noncircular+0x27b/0x320
[ 809.805558][ T428] ? print_circular_bug.isra.42+0x300/0x300
[ 809.805559][ T428] ? data_alloc.isra.8+0x15f/0x470
[ 809.805560][ T428] ? mark_lock.part.47+0x109/0x1a30
[ 809.805560][ T428] ? data_push_tail.part.6+0x310/0x310
[ 809.805561][ T428] ? print_usage_bug+0x1a0/0x1a0
[ 809.805562][ T428] check_prevs_add+0x38e/0x26f0
[ 809.805563][ T428] ? lock_is_held_type+0x19/0xe0
[ 809.805563][ T428] ? check_irq_usage+0xbb0/0xbb0
[ 809.805564][ T428] ? rcu_read_lock_held+0xb0/0xb0
[ 809.805565][ T428] __lock_acquire+0x2b9e/0x3920
[ 809.805566][ T428] ? __add_preferred_console.constprop.25+0x1d0/0x1d0
[ 809.805567][ T428] ? lockdep_hardirqs_on_prepare+0x3d0/0x3d0
[ 809.805567][ T428] lock_acquire+0x1c8/0x820
[ 809.805568][ T428] ? down_trylock+0xe/0x70
[ 809.805569][ T428] ? rcu_read_unlock+0x40/0x40
[ 809.805570][ T428] ? vprintk_emit+0x89/0x2c0
[ 809.805571][ T428] ? lock_downgrade+0x700/0x700
[ 809.805572][ T428] ? rcu_read_unlock+0x40/0x40
[ 809.805573][ T428] ? vprintk_emit+0x107/0x2c0
[ 809.805575][ T428] _raw_spin_lock_irqsave+0x30/0x50
[ 809.805576][ T428] ? down_trylock+0xe/0x70
[ 809.805577][ T428] down_trylock+0xe/0x70
[ 809.805578][ T428] __down_trylock_console_sem+0x23/0x90
[ 809.805578][ T428] console_trylock+0xe/0x60
[ 809.805579][ T428] vprintk_emit+0x107/0x2c0
[ 809.805580][ T428] ? sched_cpu_dying+0x10f/0x130
[ 809.805581][ T428] printk+0x9a/0xc0
[ 809.805582][ T428] ? record_print_text.cold.38+0x11/0x11
[ 809.805583][ T428] report_bug.cold.2+0x30/0x52
[ 809.805584][ T428] handle_bug+0x44/0x80
[ 809.805585][ T428] exc_invalid_op+0x13/0x40
[ 809.805585][ T428] asm_exc_invalid_op+0x12/0x20
[ 809.805586][ T428] RIP: 0010:sched_cpu_dying+0x10f/0x130
[ 809.805588][ T428] Code: 10 00 31 c0 48 83 c4 08 5b 41 5c 41 5d 5d c3 be 08 00 00 00 48 c7 c7 60 3f b5 96 e8 ab 81 4d 00 f0 4c 01 25 73 c4 5a 09 eb a3 <0f> 0b 48 89 34 24 e8 86 7d 4d 00 48 8b 34 24 e9 5d ff ff ff e8 88
[ 809.805589][ T428] RSP: 0018:ffffc9000889fca0 EFLAGS: 00010002
[ 809.805591][ T428] RAX: 0000000000000000 RBX: ffff8887dfcb23c0 RCX: ffffffff8e057e0d
[ 809.805591][ T428] RDX: 1ffff110fbf96480 RSI: 0000000000007c11 RDI: ffff8887dfcb2400
[ 809.805593][ T428] RBP: ffffc9000889fcc0 R08: fffffbfff2cb8e96 R09: fffffbfff2cb8e96
[ 809.805594][ T428] R10: ffffffff965c74af R11: fffffbfff2cb8e95 R12: ffff8887dfcb23d8
[ 809.805594][ T428] R13: 0000000000000086 R14: ffffffff8d5038e0 R15: 0000000000000003
[ 809.805595][ T428] ? cpuhp_invoke_callback+0x1520/0x1520
[ 809.805596][ T428] ? prandom_u32+0x18d/0x390
[ 809.805597][ T428] ? x86_pmu_starting_cpu+0x20/0x20
[ 809.805598][ T428] ? sched_cpu_wait_empty+0x220/0x220
[ 809.805599][ T428] cpuhp_invoke_callback+0x1d8/0x1520
[ 809.805600][ T428] ? x2apic_send_IPI_mask+0x10/0x10
[ 809.805600][ T428] ? clear_local_APIC+0x788/0xc10
[ 809.805601][ T428] ? cpuhp_invoke_callback+0x1520/0x1520
[ 809.805602][ T428] take_cpu_down+0x10f/0x1a0
[ 809.805603][ T428] multi_cpu_stop+0x149/0x350
[ 809.805603][ T428] ? stop_machine_yield+0x10/0x10
[ 809.805604][ T428] cpu_stopper_thread+0x200/0x400
[ 809.805605][ T428] ? cpu_stop_create+0x70/0x70
[ 809.805606][ T428] smpboot_thread_fn+0x30a/0x770
[ 809.805607][ T428] ? smpboot_register_percpu_thread+0x370/0x370
[ 809.805607][ T428] ? trace_hardirqs_on+0x1c/0x150
[ 809.805608][ T428] ? __kthread_parkme+0xcc/0x1a0
[ 809.805609][ T428] ? smpboot_register_percpu_thread+0x370/0x370
[ 809.805610][ T428] kthread+0x352/0x420
[ 809.805611][ T428] ? kthread_create_on_node+0xc0/0xc0
[ 809.805612][ T428] ret_from_fork+0x22/0x30
[ 809.805613][ T428] ======================================================
[ 809.805614][ T428] WARNING: possible circular locking dependency detected
[ 809.805616][ T428] 5.10.0-rc3-next-20201113+ #1 Tainted: G I
[ 809.805617][ T428] ------------------------------------------------------
[ 809.805618][ T428] migration/72/428 is trying to acquire lock:
[ 809.805619][ T428] ffffffff962c7d58 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0xe/0x70
[ 809.805623][ T428]
[ 809.805623][ T428] but task is already holding lock:
[ 809.805624][ T428] ffff8887dfcb23d8 (&rq->lock){-.-.}-{2:2}, at: sched_cpu_dying+0x4e/0x130
[ 809.805628][ T428]
[ 809.805628][ T428] which lock already depends on the new lock.
[ 809.805629][ T428]
[ 809.805630][ T428]
[ 809.805631][ T428] the existing dependency chain (in reverse order) is:
[ 809.805631][ T428]
[ 809.805632][ T428] -> #2 (&rq->lock){-.-.}-{2:2}:
[ 809.805635][ T428] lock_acquire+0x1c8/0x820
[ 809.805636][ T428] _raw_spin_lock+0x27/0x40
[ 809.805637][ T428] task_fork_fair+0x32/0x4c0
[ 809.805637][ T428] sched_fork+0x3aa/0x8c0
[ 809.805638][ T428] copy_process+0x1c87/0x6440
[ 809.805639][ T428] kernel_clone+0xbd/0xc90
[ 809.805640][ T428] kernel_thread+0x95/0xd0
[ 809.805640][ T428] rest_init+0x21/0x28a
[ 809.805641][ T428] start_kernel+0x381/0x39f
[ 809.805642][ T428] secondary_startup_64_no_verify+0xc2/0xcb
[ 809.805642][ T428]
[ 809.805643][ T428] -> #1 (&p->pi_lock){-.-.}-{2:2}:
[ 809.805646][ T428] lock_acquire+0x1c8/0x820
[ 809.805647][ T428] _raw_spin_lock_irqsave+0x30/0x50
[ 809.805648][ T428] try_to_wake_up+0x9b/0xc40
[ 809.805648][ T428] up+0x8d/0xd0
[ 809.805649][ T428] __up_console_sem+0x29/0x60
[ 809.805650][ T428] 0x89/0x2c0
[ 809.805726][ T428] ? lock_downgrade+0x700/0x700
[ 809.805727][ T428] ? rcu_read_unlock+0x40/0x40
[ 809.805727][ T428] ? vprintk_emit+0x107/0x2c0
[ 809.805728][ T428] _raw_spin_lock_irqsave+0x30/0x50
[ 809.805729][ T428] ? down_trylock+0xe/0x70
[ 809.805729][ T428] down_trylock+0xe/0x70
[ 809.805730][ T428] __down_trylock_console_sem+0x23/0x90
[ 809.805731][ T428] console_trylock+0xe/0x60
[ 809.805732][ T428] vprintk_emit+0x107/0x2c0
[ 809.805733][ T428] ? sched_cpu_dying+0x10f/0x130
[ 809.805733][ T428] printk+0x9a/0xc0
[ 809.805734][ T428] ? record_print_text.cold.38+0x11/0x11
[ 809.805735][ T428] report_bug.cold.2+0x30/0x52
[ 809.805735][ T428] handle_bug+0x44/0x80
[ 809.805736][ T428] exc_invalid_op+0x13/0x40
[ 809.805737][ T428] asm_exc_invalid_op+0x12/0x20
[ 809.805738][ T428] RIP: 0010:sched_cpu_dying+0x10f/0x130
[ 809.805739][ T428] Code: 10 00 31 c0 48 83 c4 08 5b 41 5c 41 5d 5d c3 be 08 00 00 00 48 c7 c7 60 3f b5 96 e8 ab 81 4d 00 f0 4c 01 25 73 c4 5a 09 eb a3 <0f> 0b 48 89 34 24 e8 86 7d 4d 00 48
> rq_unlock_irqrestore(rq, &rf);
>
> calc_load_migrate(rq);