HI Cpu0 and Cpu2 have taken place in a deadlock. cpu4 hold the lock currently. and the three cpu enter into the handle_pte_fault function. Is the phenomenon could happen? The call trace is as follows. Thanks zhongjiang <0>[46435.416685] BUG: spinlock lockup on CPU#2, current: msg_server/48476 <0>[46435.416692] lock: <NULL>/0xffff880101d71868, .magic: dead4ead, .owner: msg_server/33869, .owner_cpu: 4 <4>[46435.416699] Pid: 48476, comm: msg_server Tainted: P O 3.4.24.19-0.11-default #1 <4>[46435.416703] Call Trace: <4>[46435.416717] [<ffffffff8143c79a>] show_spin_dump+0x52/0x56 <4>[46435.416723] [<ffffffff8143c9a6>] spin_dump+0x108/0x116 <4>[46435.416733] [<ffffffff81225674>] ? do_raw_spin_lock+0x64/0x110 <4>[46435.416739] [<ffffffff81225714>] do_raw_spin_lock+0x104/0x110 <4>[46435.416745] [<ffffffff81441889>] _raw_spin_lock+0x9/0x10 <4>[46435.416752] [<ffffffff8110a2ee>] handle_pte_fault+0x1ae/0xa40 <4>[46435.416766] [<ffffffff813441d4>] ? netif_rx+0x44/0xe0 <4>[46435.416774] [<ffffffff812ec3b0>] ? loopback_xmit+0x80/0xa0 <4>[46435.416779] [<ffffffff8110ae5d>] handle_mm_fault+0x13d/0x1d0 <4>[46435.416785] [<ffffffff81444f78>] do_page_fault+0x168/0x4c0 <4>[46435.416793] [<ffffffff81001600>] ? __switch_to+0x170/0x430 <4>[46435.416799] [<ffffffff814417e9>] ? _raw_spin_unlock_irq+0x9/0x20 <4>[46435.416806] [<ffffffff81064853>] ? finish_task_switch+0x63/0xd0 <4>[46435.416811] [<ffffffff8143f65c>] ? __schedule+0x39c/0x810 <4>[46435.416817] [<ffffffff81441cf5>] page_fault+0x25/0x30 <4>[46435.416827] [<ffffffff8121e386>] ? copy_user_enhanced_fast_string+0x6/0x10 <4>[46435.416836] [<ffffffff8133b97a>] ? memcpy_toiovec+0x4a/0x90 <4>[46435.416842] [<ffffffff8133c823>] skb_copy_datagram_iovec+0x63/0x250 <4>[46435.416849] [<ffffffff81383d03>] tcp_recvmsg+0x1d3/0xa10 <4>[46435.416854] [<ffffffff81382506>] ? tcp_sendmsg+0x796/0xdd0 <4>[46435.416863] [<ffffffff813a66c6>] inet_recvmsg+0x66/0x80 <4>[46435.416868] [<ffffffff813a6741>] ? inet_sendmsg+0x61/0xb0 <4>[46435.416875] [<ffffffff81330778>] sock_recvmsg+0xf8/0x130 <4>[46435.416881] [<ffffffff8132e123>] ? sock_sendmsg+0xf3/0x120 <4>[46435.416887] [<ffffffff81147efd>] ? path_put+0x1d/0x30 <4>[46435.416895] [<ffffffff8115acb7>] ? mntput_no_expire+0x27/0x140 <4>[46435.416902] [<ffffffff810ba9f2>] ? call_rcu_sched+0x12/0x20 <4>[46435.416909] [<ffffffff8112e9b0>] ? kfree+0x30/0x110 <4>[46435.416915] [<ffffffff81331484>] sys_recvfrom+0xe4/0x150 <4>[46435.416922] [<ffffffff8113e842>] ? fput+0x182/0x240 <4>[46435.416927] [<ffffffff8113b3b1>] ? filp_close+0x61/0x90 <4>[46435.416934] [<ffffffff81449319>] system_call_fastpath+0x16/0x1b <0>[46436.026368] BUG: spinlock lockup on CPU#0, current: msg_server/30122 <0>[46436.026375] lock: <NULL>/0xffff880101d71868, .magic: dead4ead, .owner: msg_server/33869, .owner_cpu: 4 <4>[46436.026380] Pid: 30122, comm: msg_server Tainted: P O 3.4.24.19-0.11-default #1 <4>[46436.026384] Call Trace: <4>[46436.026395] [<ffffffff8143c79a>] show_spin_dump+0x52/0x56 <4>[46436.026401] [<ffffffff8143c9a6>] spin_dump+0x108/0x116 <4>[46436.026409] [<ffffffff81225671>] ? do_raw_spin_lock+0x61/0x110 <4>[46436.026415] [<ffffffff81225714>] do_raw_spin_lock+0x104/0x110 <4>[46436.026421] [<ffffffff81441889>] _raw_spin_lock+0x9/0x10 <4>[46436.026427] [<ffffffff8110a2ee>] handle_pte_fault+0x1ae/0xa40 <4>[46436.026433] [<ffffffff8114c700>] ? do_last+0x440/0x930 <4>[46436.026439] [<ffffffff8110ae5d>] handle_mm_fault+0x13d/0x1d0 <4>[46436.026446] [<ffffffff81444f78>] do_page_fault+0x168/0x4c0 <4>[46436.026452] [<ffffffff8113e842>] ? fput+0x182/0x240 <4>[46436.026458] [<ffffffff81441cf5>] page_fault+0x25/0x30 <5>[46436.915773] [11630280][1500002c101e7][INFO][Card:0 restore default delay time:3 s][SAS_INI][SAL_RestoreDlyTimeHandler,2761][msg_server] <4>[46437.266152] [11630367][15000009d007e][WARN][Queue 0xffff8801d34dd650, dev 68, qflag 0x4, sched busy 189, dev busy 1, disp busy 1.][BDM_SIO][sioUnplugWatchdog,152][CSD_0] <4>[46439.666771] [11630969][15000008e0046][WARN][IOD thread2 has been blocked for about 10s,current running req(SIO_DIF_WRITE, pid:157).][IOD][checkDetectReqAndTimer,317][IodDetectThread] <3>[46440.888489] os soft lockup - CPU#4 10s not feed dog [msg_server:33869]. <4>[46440.888499] Pid: 33869, comm: msg_server Tainted: P O 3.4.24.19-0.11-default #1 <4>[46440.888505] Call Trace: <4>[46440.888509] <IRQ> [<ffffffff81061064>] os_softlockup_tick+0x144/0x190 <4>[46440.888538] [<ffffffff81046cc8>] run_local_timers+0x18/0x20 <4>[46440.888543] [<ffffffff81046d08>] update_process_times+0x38/0x80 <4>[46440.888550] [<ffffffff8108aee1>] tick_sched_timer+0x61/0xc0 <4>[46440.888554] [<ffffffff8105bd34>] __run_hrtimer+0x84/0x1c0 <4>[46440.888557] [<ffffffff8108ae80>] ? tick_nohz_handler+0x110/0x110 <4>[46440.888561] [<ffffffff8103e4aa>] ? __do_softirq+0x14a/0x200 <4>[46440.888564] [<ffffffff8105c62f>] hrtimer_interrupt+0xef/0x230 <4>[46440.888569] [<ffffffff8144a71c>] ? call_softirq+0x1c/0x30 <4>[46440.888573] [<ffffffff81020c84>] smp_apic_timer_interrupt+0x64/0xa0 <4>[46440.888593] [<ffffffff81449dca>] apic_timer_interrupt+0x6a/0x70 <4>[46440.888595] <EOI> [<ffffffff810303f8>] ? native_flush_tlb_others+0xe8/0x120 <4>[46440.888608] [<ffffffff810303eb>] ? native_flush_tlb_others+0xdb/0x120 <4>[46440.888614] [<ffffffff81030599>] flush_tlb_page+0x59/0xb0 <4>[46440.888620] [<ffffffff8102f8a2>] ptep_set_access_flags+0x62/0x70 <4>[46440.888627] [<ffffffff81108ac1>] do_wp_page+0x321/0x710 <4>[46440.888633] [<ffffffff8110a4c3>] handle_pte_fault+0x383/0xa40 <4>[46440.888679] [<ffffffff813441d4>] ? netif_rx+0x44/0xe0 <4>[46440.888688] [<ffffffff812ec3b0>] ? loopback_xmit+0x80/0xa0 <4>[46440.888693] [<ffffffff8110ae5d>] handle_mm_fault+0x13d/0x1d0 <4>[46440.888698] [<ffffffff81444f78>] do_page_fault+0x168/0x4c0 <4>[46440.888705] [<ffffffff8106cb6a>] ? __dequeue_entity+0x2a/0x50 <4>[46440.888713] [<ffffffff81001600>] ? __switch_to+0x170/0x430 <4>[46440.888718] [<ffffffff8106e178>] ? set_next_entity+0x78/0x80 <4>[46440.888725] [<ffffffff814417e9>] ? _raw_spin_unlock_irq+0x9/0x20 <4>[46440.888732] [<ffffffff81064853>] ? finish_task_switch+0x63/0xd0 <4>[46440.888737] [<ffffffff8143f65c>] ? __schedule+0x39c/0x810 <4>[46440.888743] [<ffffffff81441cf5>] page_fault+0x25/0x30 <4>[46440.888753] [<ffffffff8121e386>] ? copy_user_enhanced_fast_string+0x6/0x10 <4>[46440.888761] [<ffffffff8133b97a>] ? memcpy_toiovec+0x4a/0x90 <4>[46440.888767] [<ffffffff8133c823>] skb_copy_datagram_iovec+0x63/0x250 <4>[46440.888775] [<ffffffff81383d03>] tcp_recvmsg+0x1d3/0xa10 <4>[46440.888780] [<ffffffff81382506>] ? tcp_sendmsg+0x796/0xdd0 <4>[46440.888788] [<ffffffff813a66c6>] inet_recvmsg+0x66/0x80 <4>[46440.888793] [<ffffffff813a6741>] ? inet_sendmsg+0x61/0xb0 <4>[46440.888800] [<ffffffff81330778>] sock_recvmsg+0xf8/0x130 <4>[46440.888806] [<ffffffff8132e123>] ? sock_sendmsg+0xf3/0x120 <4>[46440.888812] [<ffffffff81147efd>] ? path_put+0x1d/0x30 <4>[46440.888819] [<ffffffff8115acb7>] ? mntput_no_expire+0x27/0x140 <4>[46440.888825] [<ffffffff810ba9f2>] ? call_rcu_sched+0x12/0x20 <4>[46440.888830] [<ffffffff81157002>] ? evict+0x112/0x1a0 <4>[46440.888836] [<ffffffff81331484>] sys_recvfrom+0xe4/0x150 <4>[46440.888843] [<ffffffff8113e842>] ? fput+0x182/0x240 <4>[46440.888848] [<ffffffff8113b3b1>] ? filp_close+0x61/0x90 <4>[46440.888854] [<ffffffff81449319>] system_call_fastpath+0x16/0x1b -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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