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Message-ID: <395a3741-70c9-c345-08a4-77bc3bd3cae2@gmail.com>
Date: Thu, 24 Jan 2019 18:29:55 -0800
From: Eric Dumazet <eric.dumazet@...il.com>
To: Alexei Starovoitov <alexei.starovoitov@...il.com>,
Peter Zijlstra <peterz@...radead.org>
Cc: Alexei Starovoitov <ast@...nel.org>, davem@...emloft.net,
daniel@...earbox.net, jakub.kicinski@...ronome.com,
netdev@...r.kernel.org, kernel-team@...com, mingo@...hat.com,
will.deacon@....com, Paul McKenney <paulmck@...ux.vnet.ibm.com>,
jannh@...gle.com
Subject: Re: [PATCH v4 bpf-next 1/9] bpf: introduce bpf_spin_lock
On 01/24/2019 03:58 PM, Alexei Starovoitov wrote:
> On Thu, Jan 24, 2019 at 07:01:09PM +0100, Peter Zijlstra wrote:
>> and from NMI ...
>
> progs are not preemptable and map syscall accessors have bpf_prog_active counters.
> So nmi/kprobe progs will not be running when syscall is running.
> Hence dead lock is not possible and irq_save is not needed.
Speaking of NMI, how pcpu_freelist_push() and pop() can actually work ?
It seems bpf_get_stackid() can be called from NMI, and lockdep seems to complain loudly
lpaa5:/export/hda3/google/edumazet# ./test_progs
test_pkt_access:PASS:ipv4 48 nsec
test_pkt_access:PASS:ipv6 49 nsec
test_prog_run_xattr:PASS:load 0 nsec
test_prog_run_xattr:PASS:run 316 nsec
test_prog_run_xattr:PASS:data_size_out 316 nsec
test_prog_run_xattr:PASS:overflow 316 nsec
test_prog_run_xattr:PASS:run_no_output 431 nsec
test_prog_run_xattr:PASS:run_wrong_size_out 431 nsec
test_xdp:PASS:ipv4 1397 nsec
test_xdp:PASS:ipv6 523 nsec
test_xdp_adjust_tail:PASS:ipv4 382 nsec
test_xdp_adjust_tail:PASS:ipv6 210 nsec
test_l4lb:PASS:ipv4 143 nsec
test_l4lb:PASS:ipv6 164 nsec
libbpf: incorrect bpf_call opcode
libbpf: incorrect bpf_call opcode
test_tcp_estats:PASS: 0 nsec
test_bpf_obj_id:PASS:get-fd-by-notexist-prog-id 0 nsec
test_bpf_obj_id:PASS:get-fd-by-notexist-map-id 0 nsec
test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec
test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec
test_bpf_obj_id:PASS:get-map-info(fd) 0 nsec
test_bpf_obj_id:PASS:get-prog-info(fd) 0 nsec
test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-prog-fd-bad-nr-map-ids 0 nsec
test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec
test_bpf_obj_id:PASS:get-prog-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-prog-fd-bad-nr-map-ids 0 nsec
test_bpf_obj_id:PASS:get-prog-info(next_id->fd) 0 nsec
test_bpf_obj_id:PASS:check total prog id found by get_next_id 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec
test_bpf_obj_id:PASS:get-map-fd(next_id) 0 nsec
test_bpf_obj_id:PASS:check get-map-info(next_id->fd) 0 nsec
test_bpf_obj_id:PASS:check total map id found by get_next_id 0 nsec
test_pkt_md_access:PASS: 76 nsec
test_obj_name:PASS:check-bpf-prog-name 0 nsec
test_obj_name:PASS:check-bpf-map-name 0 nsec
test_obj_name:PASS:check-bpf-prog-name 0 nsec
test_obj_name:PASS:check-bpf-map-name 0 nsec
test_obj_name:PASS:check-bpf-prog-name 0 nsec
test_obj_name:PASS:check-bpf-map-name 0 nsec
test_obj_name:PASS:check-bpf-prog-name 0 nsec
test_obj_name:PASS:check-bpf-map-name 0 nsec
test_tp_attach_query:PASS:open 0 nsec
test_tp_attach_query:PASS:read 0 nsec
test_tp_attach_query:PASS:prog_load 0 nsec
test_tp_attach_query:PASS:bpf_obj_get_info_by_fd 0 nsec
test_tp_attach_query:PASS:perf_event_open 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_enable 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_set_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:prog_load 0 nsec
test_tp_attach_query:PASS:bpf_obj_get_info_by_fd 0 nsec
test_tp_attach_query:PASS:perf_event_open 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_enable 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_set_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:prog_load 0 nsec
test_tp_attach_query:PASS:bpf_obj_get_info_by_fd 0 nsec
test_tp_attach_query:PASS:perf_event_open 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_enable 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_set_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_tp_attach_query:PASS:perf_event_ioc_query_bpf 0 nsec
test_stacktrace_map:PASS:prog_load 0 nsec
test_stacktrace_map:PASS:open 0 nsec
test_stacktrace_map:PASS:perf_event_open 0 nsec
test_stacktrace_map:PASS:compare_map_keys stackid_hmap vs. stackmap 0 nsec
test_stacktrace_map:PASS:compare_map_keys stackmap vs. stackid_hmap 0 nsec
test_stacktrace_map:PASS:compare_stack_ips stackmap vs. stack_amap 0 nsec
test_stacktrace_build_id:PASS:prog_load 0 nsec
test_stacktrace_build_id:PASS:open 0 nsec
test_stacktrace_build_id:PASS:read 0 nsec
test_stacktrace_build_id:PASS:perf_event_open 0 nsec
test_stacktrace_build_id:PASS:perf_event_ioc_enable 0 nsec
test_stacktrace_build_id:PASS:perf_event_ioc_set_bpf 0 nsec
test_stacktrace_build_id:PASS:bpf_find_map control_map 0 nsec
test_stacktrace_build_id:PASS:bpf_find_map stackid_hmap 0 nsec
test_stacktrace_build_id:PASS:bpf_find_map stackmap 0 nsec
test_stacktrace_build_id:PASS:bpf_find_map stack_amap 0 nsec
test_stacktrace_build_id:PASS:compare_map_keys stackid_hmap vs. stackmap 0 nsec
test_stacktrace_build_id:PASS:compare_map_keys stackmap vs. stackid_hmap 0 nsec
test_stacktrace_build_id:PASS:get build_id with readelf 0 nsec
test_stacktrace_build_id:PASS:get_next_key from stackmap 0 nsec
test_stacktrace_build_id:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id:PASS:build id match 0 nsec
test_stacktrace_build_id:PASS:compare_stack_ips stackmap vs. stack_amap 0 nsec
test_stacktrace_build_id_nmi:PASS:prog_load 0 nsec
test_stacktrace_build_id_nmi:PASS:perf_event_open 0 nsec
test_stacktrace_build_id_nmi:PASS:perf_event_ioc_enable 0 nsec
test_stacktrace_build_id_nmi:PASS:perf_event_ioc_set_bpf 0 nsec
test_stacktrace_build_id_nmi:PASS:bpf_find_map control_map 0 nsec
test_stacktrace_build_id_nmi:PASS:bpf_find_map stackid_hmap 0 nsec
test_stacktrace_build_id_nmi:PASS:bpf_find_map stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:bpf_find_map stack_amap 0 nsec
test_stacktrace_build_id_nmi:PASS:compare_map_keys stackid_hmap vs. stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:compare_map_keys stackmap vs. stackid_hmap 0 nsec
test_stacktrace_build_id_nmi:PASS:get build_id with readelf 0 nsec
test_stacktrace_build_id_nmi:PASS:get_next_key from stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:lookup_elem from stackmap 0 nsec
test_stacktrace_build_id_nmi:PASS:build id match 0 nsec
test_stacktrace_map_raw_tp:PASS:prog_load raw tp 0 nsec
test_stacktrace_map_raw_tp:PASS:raw_tp_open 0 nsec
test_stacktrace_map_raw_tp:PASS:compare_map_keys stackid_hmap vs. stackmap 0 nsec
test_stacktrace_map_raw_tp:PASS:compare_map_keys stackmap vs. stackid_hmap 0 nsec
test_get_stack_raw_tp:PASS:prog_load raw tp 0 nsec
test_get_stack_raw_tp:PASS:raw_tp_open 0 nsec
test_get_stack_raw_tp:PASS:bpf_find_map 0 nsec
test_get_stack_raw_tp:PASS:load_kallsyms 0 nsec
test_get_stack_raw_tp:PASS:perf_event_open 0 nsec
test_get_stack_raw_tp:PASS:bpf_map_update_elem 0 nsec
test_get_stack_raw_tp:PASS:ioctl PERF_EVENT_IOC_ENABLE 0 nsec
test_get_stack_raw_tp:PASS:perf_event_mmap 0 nsec
test_get_stack_raw_tp:PASS:perf_event_poller 0 nsec
test_task_fd_query_rawtp:PASS:prog_load raw tp 0 nsec
test_task_fd_query_rawtp:PASS:raw_tp_open 0 nsec
test_task_fd_query_rawtp:PASS:bpf_task_fd_query 0 nsec
test_task_fd_query_rawtp:PASS:check_results 0 nsec
test_task_fd_query_rawtp:PASS:bpf_task_fd_query (len = 0) 0 nsec
test_task_fd_query_rawtp:PASS:check_results 0 nsec
test_task_fd_query_rawtp:PASS:bpf_task_fd_query (buf = 0) 0 nsec
test_task_fd_query_rawtp:PASS:check_results 0 nsec
test_task_fd_query_rawtp:PASS:bpf_task_fd_query (len = 3) 0 nsec
test_task_fd_query_rawtp:PASS:check_results 0 nsec
test_task_fd_query_tp_core:PASS:bpf_prog_load 0 nsec
test_task_fd_query_tp_core:PASS:open 0 nsec
test_task_fd_query_tp_core:PASS:read 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_open 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_ioc_enable 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_ioc_set_bpf 0 nsec
test_task_fd_query_tp_core:PASS:bpf_task_fd_query 0 nsec
test_task_fd_query_tp_core:PASS:check_results 0 nsec
test_task_fd_query_tp_core:PASS:bpf_prog_load 0 nsec
test_task_fd_query_tp_core:PASS:open 0 nsec
test_task_fd_query_tp_core:PASS:read 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_open 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_ioc_enable 0 nsec
test_task_fd_query_tp_core:PASS:perf_event_ioc_set_bpf 0 nsec
test_task_fd_query_tp_core:PASS:bpf_task_fd_query 0 nsec
test_task_fd_query_tp_core:PASS:check_results 0 nsec
test_reference_tracking:PASS:sk_lookup_success 0 nsec
test_reference_tracking:PASS:sk_lookup_success_simple 0 nsec
test_reference_tracking:PASS:fail_use_after_free 0 nsec
test_reference_tracking:PASS:fail_modify_sk_pointer 0 nsec
test_reference_tracking:PASS:fail_modify_sk_or_null_pointer 0 nsec
test_reference_tracking:PASS:fail_no_release 0 nsec
test_reference_tracking:PASS:fail_release_twice 0 nsec
test_reference_tracking:PASS:fail_release_unchecked 0 nsec
test_reference_tracking:PASS:fail_no_release_subcall 0 nsec
test_queue_stack_map:PASS:bpf_map_pop_elem 342 nsec
test_queue_stack_map:PASS:check-queue-stack-map-empty 323 nsec
test_queue_stack_map:PASS:bpf_map_push_elem 323 nsec
test_queue_stack_map:PASS:bpf_map_pop_elem 325 nsec
test_queue_stack_map:PASS:check-queue-stack-map-empty 311 nsec
test_queue_stack_map:PASS:bpf_map_push_elem 311 nsec
Summary: 175 PASSED, 2 FAILED
[ 429.727565] ========================================================
[ 429.733916] WARNING: possible irq lock inversion dependency detected
[ 429.740282] 5.0.0-dbg-DEV #550 Not tainted
[ 429.744381] --------------------------------------------------------
[ 429.750743] dd/16374 just changed the state of lock:
[ 429.755751] 0000000062c2321f (&head->lock){+...}, at: pcpu_freelist_push+0x28/0x50
[ 429.763348] but this lock was taken by another, HARDIRQ-safe lock in the past:
[ 429.770609] (&rq->lock){-.-.}
[ 429.770610]
and interrupts could create inverse lock ordering between them.
[ 429.785089]
other info that might help us debug this:
[ 429.791630] Possible interrupt unsafe locking scenario:
[ 429.798432] CPU0 CPU1
[ 429.802964] ---- ----
[ 429.807513] lock(&head->lock);
[ 429.810746] local_irq_disable();
[ 429.816700] lock(&rq->lock);
[ 429.822322] lock(&head->lock);
[ 429.828094] <Interrupt>
[ 429.830724] lock(&rq->lock);
[ 429.833977]
*** DEADLOCK ***
[ 429.839929] 1 lock held by dd/16374:
[ 429.843526] #0: 00000000a4c09748 (rcu_read_lock){....}, at: trace_call_bpf+0x38/0x1f0
[ 429.851498]
the shortest dependencies between 2nd lock and 1st lock:
[ 429.859348] -> (&rq->lock){-.-.} {
[ 429.862847] IN-HARDIRQ-W at:
[ 429.866091] lock_acquire+0xa7/0x190
[ 429.871531] _raw_spin_lock+0x2f/0x40
[ 429.877051] scheduler_tick+0x51/0x100
[ 429.882621] update_process_times+0x6f/0x90
[ 429.888660] tick_periodic+0x2b/0xc0
[ 429.894065] tick_handle_periodic+0x25/0x70
[ 429.900096] timer_interrupt+0x15/0x20
[ 429.905729] __handle_irq_event_percpu+0x44/0x2b0
[ 429.912265] handle_irq_event+0x60/0xc0
[ 429.917924] handle_edge_irq+0x8b/0x220
[ 429.923570] handle_irq+0x21/0x30
[ 429.928724] do_IRQ+0x64/0x120
[ 429.933613] ret_from_intr+0x0/0x1d
[ 429.938935] timer_irq_works+0x5b/0xfd
[ 429.944528] setup_IO_APIC+0x378/0x82b
[ 429.950101] apic_intr_mode_init+0x16d/0x172
[ 429.956202] x86_late_time_init+0x15/0x1c
[ 429.962049] start_kernel+0x44b/0x4fe
[ 429.967532] x86_64_start_reservations+0x24/0x26
[ 429.973988] x86_64_start_kernel+0x6f/0x72
[ 429.979942] secondary_startup_64+0xa4/0xb0
[ 429.985960] IN-SOFTIRQ-W at:
[ 429.989183] lock_acquire+0xa7/0x190
[ 429.994582] _raw_spin_lock+0x2f/0x40
[ 430.000067] try_to_wake_up+0x1ef/0x610
[ 430.005740] wake_up_process+0x15/0x20
[ 430.011314] swake_up_one+0x36/0x70
[ 430.016648] rcu_gp_kthread_wake+0x3c/0x40
[ 430.022591] rcu_accelerate_cbs_unlocked+0x8c/0xd0
[ 430.029219] rcu_process_callbacks+0xdd/0xc50
[ 430.035434] __do_softirq+0x105/0x465
[ 430.040952] irq_exit+0xc8/0xd0
[ 430.045932] smp_apic_timer_interrupt+0xa5/0x230
[ 430.052387] apic_timer_interrupt+0xf/0x20
[ 430.058331] clear_page_erms+0x7/0x10
[ 430.063825] __alloc_pages_nodemask+0x165/0x390
[ 430.070201] dsalloc_pages+0x65/0x90
[ 430.075657] reserve_ds_buffers+0x136/0x500
[ 430.081679] x86_reserve_hardware+0x16d/0x180
[ 430.087874] x86_pmu_event_init+0x4b/0x210
[ 430.093828] perf_try_init_event+0x8f/0xb0
[ 430.099744] perf_event_alloc+0xa1d/0xc90
[ 430.105576] perf_event_create_kernel_counter+0x24/0x150
[ 430.112721] hardlockup_detector_event_create+0x41/0x90
[ 430.119785] hardlockup_detector_perf_enable+0xe/0x40
[ 430.126653] watchdog_nmi_enable+0xe/0x20
[ 430.132501] watchdog_enable+0xb8/0xd0
[ 430.138097] softlockup_start_fn+0x15/0x20
[ 430.144015] smp_call_on_cpu_callback+0x2a/0x60
[ 430.150393] process_one_work+0x1f4/0x580
[ 430.156231] worker_thread+0x6f/0x430
[ 430.161708] kthread+0x132/0x170
[ 430.166791] ret_from_fork+0x24/0x30
[ 430.172180] INITIAL USE at:
[ 430.175334] lock_acquire+0xa7/0x190
[ 430.180656] _raw_spin_lock_irqsave+0x3a/0x50
[ 430.186763] rq_attach_root+0x1d/0xd0
[ 430.192153] sched_init+0x30b/0x40d
[ 430.197409] start_kernel+0x283/0x4fe
[ 430.202825] x86_64_start_reservations+0x24/0x26
[ 430.209181] x86_64_start_kernel+0x6f/0x72
[ 430.215032] secondary_startup_64+0xa4/0xb0
[ 430.220964] }
[ 430.222724] ... key at: [<ffffffff88f7dc28>] __key.71964+0x0/0x8
[ 430.229345] ... acquired at:
[ 430.232404] _raw_spin_lock+0x2f/0x40
[ 430.236260] pcpu_freelist_pop+0x77/0xf0
[ 430.240349] bpf_get_stackid+0x1c4/0x440
[ 430.244465] bpf_get_stackid_tp+0x11/0x20
[ 430.250156] -> (&head->lock){+...} {
[ 430.253742] HARDIRQ-ON-W at:
[ 430.256878] lock_acquire+0xa7/0x190
[ 430.262095] _raw_spin_lock+0x2f/0x40
[ 430.267397] pcpu_freelist_push+0x28/0x50
[ 430.273088] bpf_get_stackid+0x41e/0x440
[ 430.278677] bpf_get_stackid_tp+0x11/0x20
[ 430.284350] INITIAL USE at:
[ 430.287411] lock_acquire+0xa7/0x190
[ 430.292591] _raw_spin_lock+0x2f/0x40
[ 430.297833] pcpu_freelist_populate+0xc3/0x120
[ 430.303840] htab_map_alloc+0x41e/0x550
[ 430.309245] __do_sys_bpf+0x27e/0x1b50
[ 430.314591] __x64_sys_bpf+0x1a/0x20
[ 430.319738] do_syscall_64+0x5a/0x460
[ 430.324962] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 430.331598] }
[ 430.333274] ... key at: [<ffffffff89bfce48>] __key.13162+0x0/0x8
[ 430.339821] ... acquired at:
[ 430.342795] mark_lock+0x3c4/0x630
[ 430.346371] __lock_acquire+0x3b2/0x1850
[ 430.350493] lock_acquire+0xa7/0x190
[ 430.354282] _raw_spin_lock+0x2f/0x40
[ 430.358129] pcpu_freelist_push+0x28/0x50
[ 430.362331] bpf_get_stackid+0x41e/0x440
[ 430.366438] bpf_get_stackid_tp+0x11/0x20
[ 430.372128]
stack backtrace:
[ 430.376479] CPU: 29 PID: 16374 Comm: dd Not tainted 5.0.0-dbg-DEV #550
[ 430.383008] Hardware name: Intel RML,PCH/Iota_QC_19, BIOS 2.54.0 06/07/2018
[ 430.389967] Call Trace:
[ 430.392433] dump_stack+0x67/0x95
[ 430.395756] print_irq_inversion_bug.part.38+0x1b8/0x1c4
[ 430.401066] check_usage_backwards+0x156/0x160
[ 430.405523] mark_lock+0x3c4/0x630
[ 430.408925] ? mark_lock+0x3c4/0x630
[ 430.412496] ? print_shortest_lock_dependencies+0x1b0/0x1b0
[ 430.418092] __lock_acquire+0x3b2/0x1850
[ 430.422018] ? find_get_entry+0x1b1/0x320
[ 430.426050] ? find_get_entry+0x1d0/0x320
[ 430.430063] lock_acquire+0xa7/0x190
[ 430.433667] ? lock_acquire+0xa7/0x190
[ 430.437433] ? pcpu_freelist_push+0x28/0x50
[ 430.441635] _raw_spin_lock+0x2f/0x40
[ 430.445317] ? pcpu_freelist_push+0x28/0x50
[ 430.449494] pcpu_freelist_push+0x28/0x50
[ 430.453513] bpf_get_stackid+0x41e/0x440
[ 430.457446] bpf_get_stackid_tp+0x11/0x20
[ 430.461450] ? trace_call_bpf+0xe4/0x1f0
[ 430.465365] ? perf_trace_run_bpf_submit+0x42/0xb0
[ 430.470155] ? perf_trace_urandom_read+0xbf/0x100
[ 430.474851] ? urandom_read+0x20f/0x350
[ 430.478685] ? vfs_read+0xb8/0x190
[ 430.482096] ? __x64_sys_read+0x61/0xd0
[ 430.485949] ? do_syscall_64+0x21/0x460
[ 430.489797] ? do_syscall_64+0x5a/0x460
[ 430.493635] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 451.715758] perf: interrupt took too long (2516 > 2500), lowering kernel.perf_event_max_sample_rate to 79000
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