Seems I can still reproduce this (see below). I don't suppose you've had any further insights since September? David --- NMI watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [90.155.74.18-ma:2834] Modules linked in: cachefiles nfsv4 nfsv3 nfsv2 nfs fscache auth_rpcgss nfs_acl lockd grace sunrpc irq event stamp: 135774 hardirqs last enabled at (135773): [<ffffffff81091701>] __call_rcu+0x241/0x253 hardirqs last disabled at (135774): [<ffffffff8155895a>] apic_timer_interrupt+0x6a/0x80 softirqs last enabled at (135762): [<ffffffff810439a8>] __do_softirq+0x25a/0x319 softirqs last disabled at (135757): [<ffffffff81043c73>] irq_exit+0x5e/0xd6 CPU: 1 PID: 2834 Comm: 90.155.74.18-ma Tainted: G W 3.19.0-fsdevel+ #1143 Hardware name: /DG965RY, BIOS MQ96510J.86A.0816.2006.0716.2308 07/16/2006 task: ffff88000ab6a410 ti: ffff88001cab8000 task.ti: ffff88001cab8000 RIP: 0010:[<ffffffffa010c418>] [<ffffffffa010c418>] nfs_client_return_marked_delegations+0x9b/0x1a9 [nfsv4] RSP: 0018:ffff88001cabbdb8 EFLAGS: 00000292 RAX: ffff880000e4b7c0 RBX: ffffffffa010c39c RCX: 0000000000000000 RDX: ffff880000e4b808 RSI: ffff88000ab6a410 RDI: ffff88000ab6a410 RBP: ffff88001cabbe08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000296 R13: ffff88001cabbd98 R14: 0000000000000002 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88003db00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f419ab7a000 CR3: 000000003a7fa000 CR4: 00000000000007e0 Stack: ffff880038dc9cc8 ffff880010e8d7f8 ffff88000ab6a410 ffff880000e4b7c0 ffff88001cabbe08 ffff880038dc9c00 ffff880038dc9c00 ffff880038dc9d30 0000000000000000 0000000000000000 ffff88001cabbe58 ffffffffa010a54f Call Trace: [<ffffffffa010a54f>] nfs4_run_state_manager+0x5da/0x5df [nfsv4] [<ffffffffa0109f75>] ? nfs4_do_reclaim+0x55d/0x55d [nfsv4] [<ffffffffa0109f75>] ? nfs4_do_reclaim+0x55d/0x55d [nfsv4] [<ffffffff81059b9d>] kthread+0x10e/0x116 [<ffffffff81059a8f>] ? kthread_create_on_node+0x1bb/0x1bb [<ffffffff815579ac>] ret_from_fork+0x7c/0xb0 [<ffffffff81059a8f>] ? kthread_create_on_node+0x1bb/0x1bb Code: 00 48 89 45 c8 4c 8b 65 c8 48 8d 83 f8 07 00 00 48 89 45 b8 4c 3b 65 b8 0f 84 d6 00 00 00 49 8d 54 24 48 f0 41 0f ba 74 24 48 01 <72> 05 45 31 f6 eb 03 41 b6 01 f0 0f ba 32 02 72 02 eb 36 45 84 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html