Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754901AbaBSSJU (ORCPT ); Wed, 19 Feb 2014 13:09:20 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:37046 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754869AbaBSSJO (ORCPT ); Wed, 19 Feb 2014 13:09:14 -0500 Message-ID: <5304F32A.4040907@oracle.com> Date: Wed, 19 Feb 2014 13:08:42 -0500 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Peter Zijlstra CC: Michael wang , Ingo Molnar , LKML Subject: sched: hang in migrate_swap Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, While fuzzing with trinity inside a KVM tools guest, running latest -next kernel, I see to hit the following hang quite often. The initial spew is: [ 293.110057] BUG: soft lockup - CPU#8 stuck for 22s! [migration/8:258] [ 293.110057] Modules linked in: [ 293.110057] irq event stamp: 20828 [ 293.110057] hardirqs last enabled at (20827): [] restore_args+0x0/0x30 [ 293.110057] hardirqs last disabled at (20828): [] apic_timer_interrupt+0x6d/0x80 [ 293.110057] softirqs last enabled at (20826): [] __do_softirq+0x447/0x4f0 [ 293.110057] softirqs last disabled at (20821): [] irq_exit+0x83/0x160 [ 293.110057] CPU: 8 PID: 258 Comm: migration/8 Tainted: G W 3.14.0-rc3-next-20140218-sasha-00008-g16140ff-dirty #109 [ 293.110057] task: ffff8805b8283000 ti: ffff8805b82c0000 task.ti: ffff8805b82c0000 [ 293.110057] RIP: 0010:[] [] multi_cpu_stop+0xc2/0x1c0 [ 293.110057] RSP: 0000:ffff8805b82c1cd8 EFLAGS: 00000293 [ 293.110057] RAX: 0000000000000001 RBX: ffffffff84385437 RCX: 0000000000000000 [ 293.110057] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8800c40bb978 [ 293.110057] RBP: ffff8805b82c1d18 R08: 0000000000000000 R09: 0000000000000000 [ 293.110057] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8805b82c1c48 [ 293.110057] R13: ffff8805b8283000 R14: ffff8805b82c0000 R15: ffff8805b8283000 [ 293.110057] FS: 0000000000000000(0000) GS:ffff8805b9000000(0000) knlGS:0000000000000000 [ 293.110057] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 293.110057] CR2: 0000000000942d58 CR3: 0000000005c26000 CR4: 00000000000006e0 [ 293.110057] DR0: 000000000089e000 DR1: 00007f938d51a000 DR2: 0000000000000000 [ 293.110057] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 293.110057] Stack: [ 293.110057] ffff8805b91d0be0 00000000c40bb9d8 ffff8805b82c1cf8 ffff8805b91d0be0 [ 293.110057] ffff8800c40bba28 ffffffff812037d0 ffff8800c40bb978 ffff8805b91d0c30 [ 293.110057] ffff8805b82c1de8 ffffffff81202f56 0000000000000001 ffffffff81202e44 [ 293.110057] Call Trace: [ 293.110057] [] ? stop_cpus+0x60/0x60 [ 293.110057] [] cpu_stopper_thread+0x96/0x190 [ 293.110057] [] ? cpu_stop_should_run+0x44/0x60 [ 293.110057] [] ? __lock_release+0x1da/0x1f0 [ 293.110057] [] ? _raw_spin_unlock_irqrestore+0x65/0xb0 [ 293.110057] [] ? trace_hardirqs_on+0xd/0x10 [ 293.110057] [] smpboot_thread_fn+0x2b6/0x2c0 [ 293.110057] [] ? smpboot_register_percpu_thread+0x100/0x100 [ 293.110057] [] kthread+0x105/0x110 [ 293.110057] [] ? wait_for_completion+0xc2/0x110 [ 293.110057] [] ? set_kthreadd_affinity+0x30/0x30 [ 293.110057] [] ret_from_fork+0x7c/0xb0 [ 293.110057] [] ? set_kthreadd_affinity+0x30/0x30 [ 293.110057] Code: b5 05 01 66 0f 1f 44 00 00 45 89 ed 4d 0f a3 2e 45 19 ed 45 85 ed 41 0f 95 c7 4c 8d 73 24 31 c0 c7 45 cc 00 00 00 00 66 90 f3 90 <44> 8b 6b 20 41 39 c5 74 66 41 83 fd 02 74 0f 41 83 fd 03 75 41 This is followed by a dump of the rest of the CPU states, and I see the following: [ 268.450444] NMI backtrace for cpu 34 [ 268.450444] CPU: 34 PID: 9859 Comm: trinity-c129 Tainted: G W 3.14.0-rc3-next-20140218-sasha-00008-g16140ff-dirty #109 [ 268.450444] task: ffff880154aa3000 ti: ffff8800c40ba000 task.ti: ffff8800c40ba000 [ 268.450444] RIP: 0010:[] [] pvclock_clocksource_read+0x1a/0xc0 [ 268.450444] RSP: 0018:ffff8800c40bb538 EFLAGS: 00000082 [ 268.450444] RAX: 00000000905f62ec RBX: ffff8805b93d8500 RCX: 000000000000000a [ 268.450444] RDX: 00000000000000a1 RSI: 0000000000000040 RDI: ffff881027f12880 [ 268.450444] RBP: ffff8800c40bb548 R08: 0000000000000000 R09: 0000000000000001 [ 268.450444] R10: 0000000000000002 R11: 0000000000000001 R12: ffff8805b93d8510 [ 268.450444] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 [ 268.450444] FS: 00007f938e16a700(0000) GS:ffff8805b9200000(0000) knlGS:0000000000000000 [ 268.450444] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 268.450444] CR2: 00007f938a658a38 CR3: 00000000c40b2000 CR4: 00000000000006e0 [ 268.450444] DR0: 000000000089e000 DR1: 00007f938d51a000 DR2: 0000000000000000 [ 268.450444] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000f7060a [ 268.450444] Stack: [ 268.450444] ffff8805b93d8500 ffff8805b93d8510 ffff8800c40bb558 ffffffff810b6f04 [ 268.450444] ffff8800c40bb568 ffffffff81076e1d ffff8800c40bb598 ffffffff81180635 [ 268.450444] ffffffff875f7be0 0000000000000022 00000000001d8500 ffff8805b93d8500 [ 268.450444] Call Trace: [ 268.450444] [] kvm_clock_read+0x24/0x50 [ 268.450444] [] sched_clock+0x1d/0x30 [ 268.450444] [] sched_clock_local+0x25/0x90 [ 268.450444] [] sched_clock_cpu+0xb8/0x110 [ 268.450444] [] local_clock+0x2d/0x40 [ 268.450444] [] __lock_acquire+0x2a8/0x580 [ 268.450444] [] ? update_blocked_averages+0x61d/0x670 [ 268.450444] [] lock_acquire+0x182/0x1d0 [ 268.450444] [] ? idle_balance+0x3c/0x2c0 [ 268.450444] [] idle_balance+0x71/0x2c0 [ 268.450444] [] ? idle_balance+0x3c/0x2c0 [ 268.450444] [] pick_next_task_fair+0x24e/0x290 [ 268.450444] [] ? dequeue_task+0x6e/0x80 [ 268.450444] [] __schedule+0x2a5/0x840 [ 268.450444] [] schedule+0x65/0x70 [ 268.450444] [] schedule_timeout+0x38/0x2a0 [ 268.450444] [] ? put_lock_stats+0xe/0x30 [ 268.450444] [] ? mark_held_locks+0x6c/0x90 [ 268.450444] [] ? _raw_spin_unlock_irq+0x2b/0x80 [ 268.450444] [] wait_for_completion+0xb7/0x110 [ 268.450444] [] ? try_to_wake_up+0x2a0/0x2a0 [ 268.450444] [] stop_two_cpus+0x261/0x2b0 [ 268.450444] [] ? __migrate_swap_task+0xa0/0xa0 [ 268.450444] [] ? kvm_clock_read+0x24/0x50 [ 268.450444] [] ? stop_cpus+0x60/0x60 [ 268.450444] [] ? stop_cpus+0x60/0x60 [ 268.450444] [] ? put_lock_stats+0xe/0x30 [ 268.450444] [] ? wait_for_completion+0x3f/0x110 [ 268.450444] [] migrate_swap+0x175/0x1a0 [ 268.450444] [] task_numa_migrate+0x510/0x600 [ 268.450444] [] ? select_task_rq_fair+0x440/0x440 [ 268.450444] [] numa_migrate_preferred+0x4d/0x60 [ 268.450444] [] task_numa_fault+0x190/0x210 [ 268.450444] [] do_huge_pmd_numa_page+0x432/0x450 [ 268.450444] [] ? put_lock_stats+0xe/0x30 [ 268.450444] [] ? delay_tsc+0xea/0x110 [ 268.450444] [] __handle_mm_fault+0x244/0x3a0 [ 268.450444] [] ? rcu_read_unlock+0x5d/0x60 [ 268.450444] [] handle_mm_fault+0x10b/0x1b0 [ 268.450444] [] ? __do_page_fault+0x2e2/0x590 [ 268.450444] [] __do_page_fault+0x551/0x590 [ 268.450444] [] ? vtime_account_user+0x91/0xa0 [ 268.450444] [] ? context_tracking_user_exit+0xa8/0x1c0 [ 268.450444] [] ? _raw_spin_unlock+0x30/0x50 [ 268.450444] [] ? vtime_account_user+0x91/0xa0 [ 268.450444] [] ? context_tracking_user_exit+0xa8/0x1c0 [ 268.450444] [] do_page_fault+0x3d/0x70 [ 268.450444] [] do_async_page_fault+0x35/0x100 [ 268.450444] [] async_page_fault+0x28/0x30 [ 268.450444] Code: 6d e1 10 00 e8 98 8a 15 00 c9 c3 66 0f 1f 44 00 00 55 48 89 e5 48 83 ec 10 8b 37 eb 06 0f 1f 40 00 89 c6 0f 1f 00 0f ae e8 0f 31 <48> c1 e2 20 89 c0 0f be 4f 1c 48 09 c2 44 8b 47 18 48 2b 57 08 The stack trace is always pointing to migrate_swap() calling stop_two_cpus(). Note that I don't see another CPU in a stopped state when it occurs. Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/