Re: CPU lockup in or near new filecache code

Chuck Lever
2019-12-11T20:01:31Z

> On Dec 11, 2019, at 1:14 PM, Chuck Lever <chuck.lever@oracle.com> wrote:
>
>
>
>> On Dec 10, 2019, at 3:45 PM, Trond Myklebust <trondmy@hammerspace.com> wrote:
>>
>> On Tue, 2019-12-10 at 11:27 -0500, Chuck Lever wrote:
>>> Under stress, I'm seeing BUGs similar to this quite a bit on my v5.5-
>>> rc1 NFS server.
>>> As near as I can tell, the nfsd thread is looping under
>>> nfsd_file_acquire somewhere.
>>>
>>> Dec 9 13:22:52 klimt kernel: watchdog: BUG: soft lockup - CPU#0
>>> stuck for 22s! [nfsd:2002]
>>> Dec 9 13:22:52 klimt kernel: Modules linked in: rpcsec_gss_krb5
>>> ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager
>>> ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal
>>> coretemp kvm_intel kvm irqbypass ext4 crct10dif_pclmul crc32_pclmul
>>> ghash_clmulni_intel mbcache jbd2 iTCO_wdt iTCO_vendor_support
>>> aesni_intel glue_helper crypto_simd cryptd pcspkr rpcrdma i2c_i801
>>> lpc_ich rdma_ucm mfd_core ib_iser rdma_cm mei_me mei iw_cm raid0
>>> ib_cm libiscsi sg scsi_transport_iscsi ioatdma wmi ipmi_si
>>> ipmi_devintf ipmi_msghandler acpi_power_meter nfsd nfs_acl lockd
>>> auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sr_mod cdrom
>>> sd_mod qedr ast drm_vram_helper drm_ttm_helper ttm drm_kms_helper
>>> crc32c_intel syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci
>>> libahci libata igb mlx4_core dca i2c_algo_bit i2c_core nvme nvme_core
>>> qede qed dm_mirror dm_region_hash dm_log dm_mod crc8 ib_uverbs dax
>>> ib_core
>>> Dec 9 13:22:52 klimt kernel: CPU: 0 PID: 2002 Comm: nfsd Tainted:
>>> G L 5.5.0-rc1-00002-gc56d8b96a170 #1400
>>> Dec 9 13:22:52 klimt kernel: Hardware name: Supermicro Super
>>> Server/X10SRL-F, BIOS 1.0c 09/09/2015
>>> Dec 9 13:22:52 klimt kernel: RIP: 0010:put_task_struct+0xc/0x28
>>> Dec 9 13:22:52 klimt kernel: Code: 05 11 01 00 75 17 48 c7 c7 b1 b4
>>> eb 81 31 c0 c6 05 4f 05 11 01 01 e8 a7 ad fd ff 0f 0b c3 48 8d 57 20
>>> 83 c8 ff f0 0f c1 47 20 <83> f8 01 75 05 e9 cf 7e fd ff 85 c0 7f 0d
>>> be 03 00 00 00 48 89 d7
>>> Dec 9 13:22:52 klimt kernel: RSP: 0018:ffffc90000f7bb88 EFLAGS:
>>> 00000213 ORIG_RAX: ffffffffffffff13
>>> Dec 9 13:22:52 klimt kernel: RAX: 0000000000000002 RBX:
>>> ffff888844120000 RCX: 0000000000000000
>>> Dec 9 13:22:52 klimt kernel: RDX: ffff888844120020 RSI:
>>> 0000000000000000 RDI: ffff888844120000
>>> Dec 9 13:22:52 klimt kernel: RBP: 0000000000000001 R08:
>>> ffff888817527b00 R09: ffffffff8121d707
>>> Dec 9 13:22:52 klimt kernel: R10: ffffc90000f7bbc8 R11:
>>> 000000008e6571d9 R12: ffff888855055750
>>> Dec 9 13:22:52 klimt kernel: R13: 0000000000000000 R14:
>>> ffff88882dcd9320 R15: ffff88881741a8c0
>>> Dec 9 13:22:52 klimt kernel: FS: 0000000000000000(0000)
>>> GS:ffff88885fc00000(0000) knlGS:0000000000000000
>>> Dec 9 13:22:52 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0:
>>> 0000000080050033
>>> Dec 9 13:22:52 klimt kernel: CR2: 00007f816a386000 CR3:
>>> 0000000855686003 CR4: 00000000001606f0
>>> Dec 9 13:22:52 klimt kernel: Call Trace:
>>> Dec 9 13:22:52 klimt kernel: wake_up_q+0x34/0x40
>>> Dec 9 13:22:52 klimt kernel:
>>> __mutex_unlock_slowpath.isra.14+0x9d/0xeb
>>> Dec 9 13:22:52 klimt kernel: fsnotify_add_mark+0x53/0x5d
>>> Dec 9 13:22:52 klimt kernel: nfsd_file_acquire+0x423/0x576 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: nfs4_get_vfs_file+0x14c/0x20f [nfsd]
>>> Dec 9 13:22:52 klimt kernel: nfsd4_process_open2+0xcd6/0xd98 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: ? fh_verify+0x42e/0x4ef [nfsd]
>>> Dec 9 13:22:52 klimt kernel: ? nfsd4_process_open1+0x233/0x29d
>>> [nfsd]
>>> Dec 9 13:22:52 klimt kernel: nfsd4_open+0x500/0x5cb [nfsd]
>>> Dec 9 13:22:52 klimt kernel: nfsd4_proc_compound+0x32a/0x5c7 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: nfsd_dispatch+0x102/0x1e2 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: svc_process_common+0x3b3/0x65d [sunrpc]
>>> Dec 9 13:22:52 klimt kernel: ? svc_xprt_put+0x12/0x21 [sunrpc]
>>> Dec 9 13:22:52 klimt kernel: ? nfsd_svc+0x2be/0x2be [nfsd]
>>> Dec 9 13:22:52 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: svc_process+0xf6/0x115 [sunrpc]
>>> Dec 9 13:22:52 klimt kernel: nfsd+0xf2/0x149 [nfsd]
>>> Dec 9 13:22:52 klimt kernel: kthread+0xf6/0xfb
>>> Dec 9 13:22:52 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74
>>> Dec 9 13:22:52 klimt kernel: ret_from_fork+0x3a/0x50
>>>
>>
>> Does the very first patch in the series I just sent out help?
>
> The test is to run (cd git; make -j12 test) on a 12-core client
> over NFSv4.1 on RDMA with disconnect injection enabled.
>
> I run the test with sys, krb5, krb5i, and krb5p.
>
> The server used to crash 0-2 times per security flavor.
>
> With your patch applied the server was stable enough to complete
> all four security flavors without a kworker lockup. A definite
> improvement. For the first patch:
>
> Tested-by: Chuck Lever <chuck.lever@oracle.com>

OK, I finally got a hit. It took a long time. I've seen this particular
stack trace before, several times.

Dec 11 14:58:34 klimt kernel: watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [nfsd:2005]
Dec 11 14:58:34 klimt kernel: Modules linked in: rpcsec_gss_krb5 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal kvm_intel coretemp kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iTCO_wdt ext4 iTCO_vendor_support aesni_intel mbcache jbd2 glue_helper rpcrdma crypto_simd cryptd rdma_ucm ib_iser rdma_cm pcspkr iw_cm ib_cm mei_me raid0 libiscsi lpc_ich mei sg scsi_transport_iscsi i2c_i801 mfd_core wmi ipmi_si ipmi_devintf ipmi_msghandler ioatdma acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sr_mod sd_mod cdrom qedr ast drm_vram_helper drm_ttm_helper ttm crc32c_intel drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm igb dca i2c_algo_bit i2c_core mlx4_core ahci libahci libata nvme nvme_core qede qed dm_mirror dm_region_hash dm_log dm_mod crc8 ib_uverbs dax ib_core
Dec 11 14:58:34 klimt kernel: CPU: 0 PID: 2005 Comm: nfsd Tainted: G W 5.5.0-rc1-00003-g170e7adc2317 #1401
Dec 11 14:58:34 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Dec 11 14:58:34 klimt kernel: RIP: 0010:__srcu_read_lock+0x23/0x24
Dec 11 14:58:34 klimt kernel: Code: 07 00 0f 1f 40 00 c3 0f 1f 44 00 00 8b 87 c8 c3 00 00 48 8b 97 f0 c3 00 00 83 e0 01 48 63 c8 65 48 ff 04 ca f0 83 44 24 fc 00 <c3> 0f 1f 44 00 00 f0 83 44 24 fc 00 48 63 f6 48 8b 87 f0 c3 00 00
Dec 11 14:58:34 klimt kernel: RSP: 0018:ffffc90001d97bd0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
Dec 11 14:58:34 klimt kernel: RAX: 0000000000000001 RBX: ffff888830d0eb78 RCX: 0000000000000001
Dec 11 14:58:34 klimt kernel: RDX: 0000000000030f00 RSI: ffff888853f4da00 RDI: ffffffff82815a40
Dec 11 14:58:34 klimt kernel: RBP: ffff88883112d828 R08: ffff888843540000 R09: ffffffff8121d707
Dec 11 14:58:34 klimt kernel: R10: ffffc90001d97bf0 R11: 0000000000001b84 R12: ffff888853f4da00
Dec 11 14:58:34 klimt kernel: R13: ffff8888132a1410 R14: ffff88883112d7e0 R15: 00000000ffffffef
Dec 11 14:58:34 klimt kernel: FS: 0000000000000000(0000) GS:ffff88885fc00000(0000) knlGS:0000000000000000
Dec 11 14:58:34 klimt kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Dec 11 14:58:34 klimt kernel: CR2: 00007f2d6a2d8000 CR3: 0000000859b38004 CR4: 00000000001606f0
Dec 11 14:58:34 klimt kernel: Call Trace:
Dec 11 14:58:34 klimt kernel: fsnotify_grab_connector+0x16/0x4f
Dec 11 14:58:34 klimt kernel: fsnotify_find_mark+0x11/0x6a
Dec 11 14:58:34 klimt kernel: nfsd_file_acquire+0x3a9/0x5b2 [nfsd]
Dec 11 14:58:34 klimt kernel: nfs4_get_vfs_file+0x14c/0x20f [nfsd]
Dec 11 14:58:34 klimt kernel: nfsd4_process_open2+0xcd6/0xd98 [nfsd]
Dec 11 14:58:34 klimt kernel: ? fh_verify+0x42e/0x4ef [nfsd]
Dec 11 14:58:34 klimt kernel: ? nfsd4_process_open1+0x233/0x29d [nfsd]
Dec 11 14:58:34 klimt kernel: nfsd4_open+0x500/0x5cb [nfsd]
Dec 11 14:58:34 klimt kernel: nfsd4_proc_compound+0x32a/0x5c7 [nfsd]
Dec 11 14:58:34 klimt kernel: nfsd_dispatch+0x102/0x1e2 [nfsd]
Dec 11 14:58:34 klimt kernel: svc_process_common+0x3b3/0x65d [sunrpc]
Dec 11 14:58:34 klimt kernel: ? svc_xprt_put+0x12/0x21 [sunrpc]
Dec 11 14:58:34 klimt kernel: ? nfsd_svc+0x2be/0x2be [nfsd]
Dec 11 14:58:34 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd]
Dec 11 14:58:34 klimt kernel: svc_process+0xf6/0x115 [sunrpc]
Dec 11 14:58:34 klimt kernel: nfsd+0xf2/0x149 [nfsd]
Dec 11 14:58:34 klimt kernel: kthread+0xf6/0xfb
Dec 11 14:58:34 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74
Dec 11 14:58:34 klimt kernel: ret_from_fork+0x3a/0x50

--
Chuck Lever