2014-05-08 14:28:46

by Klemens Senn

[permalink] [raw]
Subject: Soft lockup in unloading kernel modules

Hi,

I am getting a soft lockup on the NFS server on its reboot if at least
one client mount is established. I am using OpenSUSE 12.3 with the
nfs-rdma kernel from Anna Schumaker
(git://git.linux-nfs.org/projects/anna/nfs-rdma.git).

The export on the server side is done with
/data *(fsid=0,crossmnt,rw,mp,no_root_squash,sync,no_subtree_check,insecure)

Following command is used for mounting the NFSv4 share:
mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.19:/ /mnt

The HCA is a Mellanox MT4099 on the server and the client.

The soft lockup can be reproduced by following steps:
o server: Start the nfs server
o client: Mount the share
o client: Do a "ls" in the mounted directory
o server: Stop the nfs server
o server: Unload the nfs and mlx4 modules or reboot the server (I used
the openibd init script from the Mellanox driver without having the
Mellanox stack installed)

The server reports a soft lockup
BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:6146]
most times.

Sometimes I get following kernel panic
BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
IP: [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
PGD 82a820067 PUD 857832067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry nfnetlink_log
nfnetlink bluetooth rfkill nfsv4 svcrdma dm_mod cpuid nfs fscache lockd
sunrpc af_packet 8021q garp stp llc rdma_ucm ib_ucm rdma_cm iw_cm
ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en mlx4_ib(-) ib_sa ib_mad ib_core
ib_addr sr_mod cdrom usb_storage joydev mlx4_core usbhid
x86_pkg_temp_thermal coretemp kvm_intel kvm ghash_clmulni_intel
aesni_intel ablk_helper cryptd iTCO_wdt lrw igb gf128mul
iTCO_vendor_support ehci_pci glue_helper pcspkr i2c_algo_bit isci
ehci_hcd aes_x86_64 ptp libsas ioatdma lpc_ich microcode sb_edac sg
pps_core usbcore ipmi_si tpm_tis edac_core scsi_transport_sas i2c_i801
mfd_core dca usb_common tpm ipmi_msghandler wmi acpi_cpufreq button edd
autofs4 xfs libcrc32c crc32c_intel processor thermal_sys scsi_dh_rdac
scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh [last unloaded: oid_registry]
CPU: 0 PID: 6603 Comm: modprobe Not tainted 3.15.0-rc2-anna-nfs-rdma+ #3
Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
task: ffff88105b8c6050 ti: ffff88105d814000 task.ti: ffff88105d814000
RIP: 0010:[<ffffffff815a5c35>] [<ffffffff815a5c35>]
_raw_spin_lock_bh+0x15/0x40
RSP: 0018:ffff88105d815d18 EFLAGS: 00010286
RAX: 0000000000010000 RBX: ffffffffffffffff RCX: 0000000000000000
RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000003
RBP: ffff88105d815d18 R08: ffff88087c611f38 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88087c3c9800
R13: ffff88107b82ab00 R14: 0000000000000003 R15: 0000000000000007
FS: 00007fef64612700(0000) GS:ffff88087fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000003 CR3: 000000087c2c7000 CR4: 00000000000407f0
Stack:
ffff88105d815d58 ffffffffa05199f0 ffff88105d815d88 ffff88087c3c9800
ffff88087c3c9400 ffff88107b82ab00 ffff88087c3c9660 ffff88087c3c95c8
ffff88105d815d78 ffffffffa0421ce9 ffff88087c3c9400 ffff88107b82aac0
Call Trace:
[<ffffffffa05199f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
[<ffffffffa0421ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
[<ffffffffa039d086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
[<ffffffffa01dca86>] ib_unregister_device+0x46/0x120 [ib_core]
[<ffffffffa032ddc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
[<ffffffffa02fb9d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
[<ffffffffa02fba2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
[<ffffffffa033f4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
[<ffffffff810bd6b2>] SyS_delete_module+0x152/0x220
[<ffffffff811496e4>] ? vm_munmap+0x54/0x70
[<ffffffff815adca6>] system_call_fastpath+0x1a/0x1f
Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d c3
55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0> 0f
c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
RIP [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
RSP <ffff88105d815d18>
CR2: 0000000000000003
---[ end trace 18e02ff413ac4b9b ]---
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffff9fffffff)
---[ end Kernel panic - not syncing: Fatal exception in interrupt

Kind regards,
Klemens



2014-05-19 17:51:51

by Chuck Lever

[permalink] [raw]
Subject: Re: Soft lockup in unloading kernel modules

Hi Klemens-

On May 13, 2014, at 12:48 PM, Klemens Senn <[email protected]> wrote:

> Hi Anna,
>
> today I retried unloading the kernel modules with your updated kernel
> and additionally I tried the nfsd-next kernel from J. Bruce Fields and
> Chuck's nfs-rdma-client kernel.

I filed

https://bugzilla.linux-nfs.org/show_bug.cgi?id=252

to track this issue.


> In short: None of these was able to unload the kernel modules with an
> active connection.
>
> In detail:
>
> With your kernel I got following 3 faults:
> o BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:4615]
> o BUG: unable to handle kernel NULL pointer dereference at
> 0000000000000003
> o BUG: unable to handle kernel paging request at 0000000000005b8c
>
> With the nfsd-next kernel I got following results:
> o BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:4452]
> o module unloading blocks forever, dmesg shows:
> nfsd: last server has exited, flushing export cache
> waiting module removal not supported: please upgrade
> o Kernel keeps running but reports the following:
> nfsd: last server has exited, flushing export cache
> waiting module removal not supported: please upgrade
> svc_xprt_enqueue: threads and transports both waiting??
> INFO: task modprobe:4510 blocked for more than 480 seconds.
> Not tainted 3.15.0-rc1-bfields-master+ #1
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
> message.
> modprobe D ffff88087fc13440 0 4510 4458 0x00000000
> ffff88105bb23c58 0000000000000086 ffff88105c14e690 0000000000013440
> ffff88105bb23fd8 0000000000013440 ffffffff81a14480 ffff88105c14e690
> 0000000000000037 ffff88085d7f74d8 ffff88085d7f74e0 7fffffffffffffff
> Call Trace:
> [<ffffffff815a2424>] schedule+0x24/0x70
> [<ffffffff815a18cc>] schedule_timeout+0x1ec/0x260
> [<ffffffff8159a504>] ? printk+0x5c/0x5e
> [<ffffffff815a3406>] wait_for_completion+0x96/0x100
> [<ffffffff81080c90>] ? try_to_wake_up+0x2b0/0x2b0
> [<ffffffffa0314039>] cma_remove_one+0x1a9/0x220 [rdma_cm]
> [<ffffffffa01fea86>] ib_unregister_device+0x46/0x120 [ib_core]
> [<ffffffffa02c5dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
> [<ffffffffa04319d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
> [<ffffffffa0431a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
> [<ffffffffa02d74cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
> [<ffffffff810bd612>] SyS_delete_module+0x152/0x220
> [<ffffffff81149684>] ? vm_munmap+0x54/0x70
> [<ffffffff815ad5a6>] system_call_fastpath+0x1a/0x1f
>
> With the nfs-rdma-client I got following results:
> o module unloading blocks forever, dmesg shows:
> nfsd: last server has exited, flushing export cache
> svc_xprt_enqueue: threads and transports both waiting??
> o BUG: unable to handle kernel paging request at 0000000000004dec
> IP: [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
> PGD 107ba9a067 PUD 105c093067 PMD 0
> Oops: 0002 [#1] SMP
> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry svcrdma
> dm_mod cpuid nfs fscache lockd sunrpc af_packet 8021q garp stp llc
> rdma_ucm ib_ucm rdma_cm iw_cm ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en
> mlx4_ib(-) ib_sa ib_mad ib_core ib_addr sr_mod cdrom usb_storage joydev
> mlx4_core usbhid x86_pkg_temp_thermal coretemp kvm_intel kvm
> ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul
> glue_helper ehci_pci aes_x86_64 ehci_hcd isci iTCO_wdt libsas pcspkr
> iTCO_vendor_support igb i2c_algo_bit sb_edac lpc_ich edac_core ioatdma
> usbcore tpm_tis ptp microcode i2c_i801 sg mfd_core scsi_transport_sas
> ipmi_si usb_common tpm wmi pps_core dca ipmi_msghandler acpi_cpufreq
> button edd autofs4 xfs libcrc32c crc32c_intel processor thermal_sys
> scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh
> CPU: 14 PID: 4813 Comm: modprobe Not tainted
> 3.15.0-rc5-cel-nfs-rdma-client-unpatched+ #2
> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
> task: ffff88085bf96190 ti: ffff88085d42a000 task.ti: ffff88085d42a000
> RIP: 0010:[<ffffffff815a63b5>] [<ffffffff815a63b5>]
> _raw_spin_lock_bh+0x15/0x40
> RSP: 0018:ffff88085d42bd18 EFLAGS: 00010286
> RAX: 0000000000010000 RBX: 0000000000004de8 RCX: 0000000000000000
> RDX: 000000000000000b RSI: 000000000000000e RDI: 0000000000004dec
> RBP: ffff88085d42bd18 R08: ffff88087c611f38 R09: 000000000000a140
> R10: 000000000000002b R11: 0000000000000000 R12: ffff88085dcc3c00
> R13: ffff88105ca13280 R14: 0000000000004dec R15: 0000000000004df0
> FS: 00007f0e49fb5700(0000) GS:ffff88107fcc0000(0000)
> knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000004dec CR3: 000000105b027000 CR4: 00000000000407e0
> Stack:
> ffff88085d42bd58 ffffffffa03bd9f0 0000000001328b88 ffff88085dcc3c00
> ffff88085dce8000 ffff88105ca13280 ffff88085dce8260 ffff88085dce81c8
> ffff88085d42bd78 ffffffffa0441ce9 ffff88085dce8000 ffff88105ca13240
> Call Trace:
> [<ffffffffa03bd9f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
> [<ffffffffa0441ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
> [<ffffffffa031a086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
> [<ffffffffa0261a86>] ib_unregister_device+0x46/0x120 [ib_core]
> [<ffffffffa02b9dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
> [<ffffffffa02329d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
> [<ffffffffa0232a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
> [<ffffffffa02cb4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
> [<ffffffff810bd6f0>] SyS_delete_module+0x170/0x1f0
> [<ffffffff811497f4>] ? vm_munmap+0x54/0x70
> [<ffffffff815ae426>] system_call_fastpath+0x1a/0x1f
> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d
> c3 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0>
> 0f c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
> RIP [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
> RSP <ffff88085d42bd18>
> CR2: 0000000000004dec
> ---[ end trace bf1fd548a33cbfc4 ]---
> Kernel panic - not syncing: Fatal exception in interrupt
> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
> 0xffffffff80000000-0xffffffff9fffffff)
> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>
>
> Regards,
> Klemens
>
>
> On 05/08/2014 05:59 PM, Anna Schumaker wrote:
>> I haven't applied Chuck's recent (v3) patches to that kernel yet (I've been waiting to see if people have comments). I'll try to push something out today.
>>
>> On 05/08/2014 10:28 AM, Senn Klemens wrote:
>>> Hi,
>>>
>>> I am getting a soft lockup on the NFS server on its reboot if at least
>>> one client mount is established. I am using OpenSUSE 12.3 with the
>>> nfs-rdma kernel from Anna Schumaker
>>> (git://git.linux-nfs.org/projects/anna/nfs-rdma.git).
>>>
>>> The export on the server side is done with
>>> /data *(fsid=0,crossmnt,rw,mp,no_root_squash,sync,no_subtree_check,insecure)
>>>
>>> Following command is used for mounting the NFSv4 share:
>>> mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.19:/ /mnt
>>>
>>> The HCA is a Mellanox MT4099 on the server and the client.
>>>
>>> The soft lockup can be reproduced by following steps:
>>> o server: Start the nfs server
>>> o client: Mount the share
>>> o client: Do a "ls" in the mounted directory
>>> o server: Stop the nfs server
>>> o server: Unload the nfs and mlx4 modules or reboot the server (I used
>>> the openibd init script from the Mellanox driver without having the
>>> Mellanox stack installed)
>>>
>>> The server reports a soft lockup
>>> BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:6146]
>>> most times.
>>>
>>> Sometimes I get following kernel panic
>>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
>>> IP: [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>>> PGD 82a820067 PUD 857832067 PMD 0
>>> Oops: 0002 [#1] SMP
>>> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry nfnetlink_log
>>> nfnetlink bluetooth rfkill nfsv4 svcrdma dm_mod cpuid nfs fscache lockd
>>> sunrpc af_packet 8021q garp stp llc rdma_ucm ib_ucm rdma_cm iw_cm
>>> ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en mlx4_ib(-) ib_sa ib_mad ib_core
>>> ib_addr sr_mod cdrom usb_storage joydev mlx4_core usbhid
>>> x86_pkg_temp_thermal coretemp kvm_intel kvm ghash_clmulni_intel
>>> aesni_intel ablk_helper cryptd iTCO_wdt lrw igb gf128mul
>>> iTCO_vendor_support ehci_pci glue_helper pcspkr i2c_algo_bit isci
>>> ehci_hcd aes_x86_64 ptp libsas ioatdma lpc_ich microcode sb_edac sg
>>> pps_core usbcore ipmi_si tpm_tis edac_core scsi_transport_sas i2c_i801
>>> mfd_core dca usb_common tpm ipmi_msghandler wmi acpi_cpufreq button edd
>>> autofs4 xfs libcrc32c crc32c_intel processor thermal_sys scsi_dh_rdac
>>> scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh [last unloaded: oid_registry]
>>> CPU: 0 PID: 6603 Comm: modprobe Not tainted 3.15.0-rc2-anna-nfs-rdma+ #3
>>> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
>>> task: ffff88105b8c6050 ti: ffff88105d814000 task.ti: ffff88105d814000
>>> RIP: 0010:[<ffffffff815a5c35>] [<ffffffff815a5c35>]
>>> _raw_spin_lock_bh+0x15/0x40
>>> RSP: 0018:ffff88105d815d18 EFLAGS: 00010286
>>> RAX: 0000000000010000 RBX: ffffffffffffffff RCX: 0000000000000000
>>> RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000003
>>> RBP: ffff88105d815d18 R08: ffff88087c611f38 R09: 0000000000000001
>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff88087c3c9800
>>> R13: ffff88107b82ab00 R14: 0000000000000003 R15: 0000000000000007
>>> FS: 00007fef64612700(0000) GS:ffff88087fc00000(0000) knlGS:0000000000000000
>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 0000000000000003 CR3: 000000087c2c7000 CR4: 00000000000407f0
>>> Stack:
>>> ffff88105d815d58 ffffffffa05199f0 ffff88105d815d88 ffff88087c3c9800
>>> ffff88087c3c9400 ffff88107b82ab00 ffff88087c3c9660 ffff88087c3c95c8
>>> ffff88105d815d78 ffffffffa0421ce9 ffff88087c3c9400 ffff88107b82aac0
>>> Call Trace:
>>> [<ffffffffa05199f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
>>> [<ffffffffa0421ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
>>> [<ffffffffa039d086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
>>> [<ffffffffa01dca86>] ib_unregister_device+0x46/0x120 [ib_core]
>>> [<ffffffffa032ddc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
>>> [<ffffffffa02fb9d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
>>> [<ffffffffa02fba2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
>>> [<ffffffffa033f4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
>>> [<ffffffff810bd6b2>] SyS_delete_module+0x152/0x220
>>> [<ffffffff811496e4>] ? vm_munmap+0x54/0x70
>>> [<ffffffff815adca6>] system_call_fastpath+0x1a/0x1f
>>> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d c3
>>> 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0> 0f
>>> c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
>>> RIP [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>>> RSP <ffff88105d815d18>
>>> CR2: 0000000000000003
>>> ---[ end trace 18e02ff413ac4b9b ]---
>>> Kernel panic - not syncing: Fatal exception in interrupt
>>> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
>>> 0xffffffff80000000-0xffffffff9fffffff)
>>> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>>>
>>> Kind regards,
>>> Klemens
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>>> the body of a message to [email protected]
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com




2014-05-19 21:02:52

by Shirley Ma

[permalink] [raw]
Subject: Re: Soft lockup in unloading kernel modules

Klements,

Can you add more details on how to unloading the modules (step by step)
in the bug report?

Thanks
Shirley

On 05/19/2014 10:51 AM, Chuck Lever wrote:
> Hi Klemens-
>
> On May 13, 2014, at 12:48 PM, Klemens Senn <[email protected]> wrote:
>
>> Hi Anna,
>>
>> today I retried unloading the kernel modules with your updated kernel
>> and additionally I tried the nfsd-next kernel from J. Bruce Fields and
>> Chuck's nfs-rdma-client kernel.
> I filed
>
> https://bugzilla.linux-nfs.org/show_bug.cgi?id=252
>
> to track this issue.
>
>
>> In short: None of these was able to unload the kernel modules with an
>> active connection.
>>
>> In detail:
>>
>> With your kernel I got following 3 faults:
>> o BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:4615]
>> o BUG: unable to handle kernel NULL pointer dereference at
>> 0000000000000003
>> o BUG: unable to handle kernel paging request at 0000000000005b8c
>>
>> With the nfsd-next kernel I got following results:
>> o BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:4452]
>> o module unloading blocks forever, dmesg shows:
>> nfsd: last server has exited, flushing export cache
>> waiting module removal not supported: please upgrade
>> o Kernel keeps running but reports the following:
>> nfsd: last server has exited, flushing export cache
>> waiting module removal not supported: please upgrade
>> svc_xprt_enqueue: threads and transports both waiting??
>> INFO: task modprobe:4510 blocked for more than 480 seconds.
>> Not tainted 3.15.0-rc1-bfields-master+ #1
>> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
>> message.
>> modprobe D ffff88087fc13440 0 4510 4458 0x00000000
>> ffff88105bb23c58 0000000000000086 ffff88105c14e690 0000000000013440
>> ffff88105bb23fd8 0000000000013440 ffffffff81a14480 ffff88105c14e690
>> 0000000000000037 ffff88085d7f74d8 ffff88085d7f74e0 7fffffffffffffff
>> Call Trace:
>> [<ffffffff815a2424>] schedule+0x24/0x70
>> [<ffffffff815a18cc>] schedule_timeout+0x1ec/0x260
>> [<ffffffff8159a504>] ? printk+0x5c/0x5e
>> [<ffffffff815a3406>] wait_for_completion+0x96/0x100
>> [<ffffffff81080c90>] ? try_to_wake_up+0x2b0/0x2b0
>> [<ffffffffa0314039>] cma_remove_one+0x1a9/0x220 [rdma_cm]
>> [<ffffffffa01fea86>] ib_unregister_device+0x46/0x120 [ib_core]
>> [<ffffffffa02c5dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
>> [<ffffffffa04319d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
>> [<ffffffffa0431a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
>> [<ffffffffa02d74cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
>> [<ffffffff810bd612>] SyS_delete_module+0x152/0x220
>> [<ffffffff81149684>] ? vm_munmap+0x54/0x70
>> [<ffffffff815ad5a6>] system_call_fastpath+0x1a/0x1f
>>
>> With the nfs-rdma-client I got following results:
>> o module unloading blocks forever, dmesg shows:
>> nfsd: last server has exited, flushing export cache
>> svc_xprt_enqueue: threads and transports both waiting??
>> o BUG: unable to handle kernel paging request at 0000000000004dec
>> IP: [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
>> PGD 107ba9a067 PUD 105c093067 PMD 0
>> Oops: 0002 [#1] SMP
>> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry svcrdma
>> dm_mod cpuid nfs fscache lockd sunrpc af_packet 8021q garp stp llc
>> rdma_ucm ib_ucm rdma_cm iw_cm ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en
>> mlx4_ib(-) ib_sa ib_mad ib_core ib_addr sr_mod cdrom usb_storage joydev
>> mlx4_core usbhid x86_pkg_temp_thermal coretemp kvm_intel kvm
>> ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul
>> glue_helper ehci_pci aes_x86_64 ehci_hcd isci iTCO_wdt libsas pcspkr
>> iTCO_vendor_support igb i2c_algo_bit sb_edac lpc_ich edac_core ioatdma
>> usbcore tpm_tis ptp microcode i2c_i801 sg mfd_core scsi_transport_sas
>> ipmi_si usb_common tpm wmi pps_core dca ipmi_msghandler acpi_cpufreq
>> button edd autofs4 xfs libcrc32c crc32c_intel processor thermal_sys
>> scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh
>> CPU: 14 PID: 4813 Comm: modprobe Not tainted
>> 3.15.0-rc5-cel-nfs-rdma-client-unpatched+ #2
>> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
>> task: ffff88085bf96190 ti: ffff88085d42a000 task.ti: ffff88085d42a000
>> RIP: 0010:[<ffffffff815a63b5>] [<ffffffff815a63b5>]
>> _raw_spin_lock_bh+0x15/0x40
>> RSP: 0018:ffff88085d42bd18 EFLAGS: 00010286
>> RAX: 0000000000010000 RBX: 0000000000004de8 RCX: 0000000000000000
>> RDX: 000000000000000b RSI: 000000000000000e RDI: 0000000000004dec
>> RBP: ffff88085d42bd18 R08: ffff88087c611f38 R09: 000000000000a140
>> R10: 000000000000002b R11: 0000000000000000 R12: ffff88085dcc3c00
>> R13: ffff88105ca13280 R14: 0000000000004dec R15: 0000000000004df0
>> FS: 00007f0e49fb5700(0000) GS:ffff88107fcc0000(0000)
>> knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 0000000000004dec CR3: 000000105b027000 CR4: 00000000000407e0
>> Stack:
>> ffff88085d42bd58 ffffffffa03bd9f0 0000000001328b88 ffff88085dcc3c00
>> ffff88085dce8000 ffff88105ca13280 ffff88085dce8260 ffff88085dce81c8
>> ffff88085d42bd78 ffffffffa0441ce9 ffff88085dce8000 ffff88105ca13240
>> Call Trace:
>> [<ffffffffa03bd9f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
>> [<ffffffffa0441ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
>> [<ffffffffa031a086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
>> [<ffffffffa0261a86>] ib_unregister_device+0x46/0x120 [ib_core]
>> [<ffffffffa02b9dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
>> [<ffffffffa02329d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
>> [<ffffffffa0232a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
>> [<ffffffffa02cb4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
>> [<ffffffff810bd6f0>] SyS_delete_module+0x170/0x1f0
>> [<ffffffff811497f4>] ? vm_munmap+0x54/0x70
>> [<ffffffff815ae426>] system_call_fastpath+0x1a/0x1f
>> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d
>> c3 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0>
>> 0f c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
>> RIP [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
>> RSP <ffff88085d42bd18>
>> CR2: 0000000000004dec
>> ---[ end trace bf1fd548a33cbfc4 ]---
>> Kernel panic - not syncing: Fatal exception in interrupt
>> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
>> 0xffffffff80000000-0xffffffff9fffffff)
>> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>>
>>
>> Regards,
>> Klemens
>>
>>
>> On 05/08/2014 05:59 PM, Anna Schumaker wrote:
>>> I haven't applied Chuck's recent (v3) patches to that kernel yet (I've been waiting to see if people have comments). I'll try to push something out today.
>>>
>>> On 05/08/2014 10:28 AM, Senn Klemens wrote:
>>>> Hi,
>>>>
>>>> I am getting a soft lockup on the NFS server on its reboot if at least
>>>> one client mount is established. I am using OpenSUSE 12.3 with the
>>>> nfs-rdma kernel from Anna Schumaker
>>>> (git://git.linux-nfs.org/projects/anna/nfs-rdma.git).
>>>>
>>>> The export on the server side is done with
>>>> /data *(fsid=0,crossmnt,rw,mp,no_root_squash,sync,no_subtree_check,insecure)
>>>>
>>>> Following command is used for mounting the NFSv4 share:
>>>> mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.19:/ /mnt
>>>>
>>>> The HCA is a Mellanox MT4099 on the server and the client.
>>>>
>>>> The soft lockup can be reproduced by following steps:
>>>> o server: Start the nfs server
>>>> o client: Mount the share
>>>> o client: Do a "ls" in the mounted directory
>>>> o server: Stop the nfs server
>>>> o server: Unload the nfs and mlx4 modules or reboot the server (I used
>>>> the openibd init script from the Mellanox driver without having the
>>>> Mellanox stack installed)
>>>>
>>>> The server reports a soft lockup
>>>> BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:6146]
>>>> most times.
>>>>
>>>> Sometimes I get following kernel panic
>>>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
>>>> IP: [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>>>> PGD 82a820067 PUD 857832067 PMD 0
>>>> Oops: 0002 [#1] SMP
>>>> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry nfnetlink_log
>>>> nfnetlink bluetooth rfkill nfsv4 svcrdma dm_mod cpuid nfs fscache lockd
>>>> sunrpc af_packet 8021q garp stp llc rdma_ucm ib_ucm rdma_cm iw_cm
>>>> ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en mlx4_ib(-) ib_sa ib_mad ib_core
>>>> ib_addr sr_mod cdrom usb_storage joydev mlx4_core usbhid
>>>> x86_pkg_temp_thermal coretemp kvm_intel kvm ghash_clmulni_intel
>>>> aesni_intel ablk_helper cryptd iTCO_wdt lrw igb gf128mul
>>>> iTCO_vendor_support ehci_pci glue_helper pcspkr i2c_algo_bit isci
>>>> ehci_hcd aes_x86_64 ptp libsas ioatdma lpc_ich microcode sb_edac sg
>>>> pps_core usbcore ipmi_si tpm_tis edac_core scsi_transport_sas i2c_i801
>>>> mfd_core dca usb_common tpm ipmi_msghandler wmi acpi_cpufreq button edd
>>>> autofs4 xfs libcrc32c crc32c_intel processor thermal_sys scsi_dh_rdac
>>>> scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh [last unloaded: oid_registry]
>>>> CPU: 0 PID: 6603 Comm: modprobe Not tainted 3.15.0-rc2-anna-nfs-rdma+ #3
>>>> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
>>>> task: ffff88105b8c6050 ti: ffff88105d814000 task.ti: ffff88105d814000
>>>> RIP: 0010:[<ffffffff815a5c35>] [<ffffffff815a5c35>]
>>>> _raw_spin_lock_bh+0x15/0x40
>>>> RSP: 0018:ffff88105d815d18 EFLAGS: 00010286
>>>> RAX: 0000000000010000 RBX: ffffffffffffffff RCX: 0000000000000000
>>>> RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000003
>>>> RBP: ffff88105d815d18 R08: ffff88087c611f38 R09: 0000000000000001
>>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff88087c3c9800
>>>> R13: ffff88107b82ab00 R14: 0000000000000003 R15: 0000000000000007
>>>> FS: 00007fef64612700(0000) GS:ffff88087fc00000(0000) knlGS:0000000000000000
>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>> CR2: 0000000000000003 CR3: 000000087c2c7000 CR4: 00000000000407f0
>>>> Stack:
>>>> ffff88105d815d58 ffffffffa05199f0 ffff88105d815d88 ffff88087c3c9800
>>>> ffff88087c3c9400 ffff88107b82ab00 ffff88087c3c9660 ffff88087c3c95c8
>>>> ffff88105d815d78 ffffffffa0421ce9 ffff88087c3c9400 ffff88107b82aac0
>>>> Call Trace:
>>>> [<ffffffffa05199f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
>>>> [<ffffffffa0421ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
>>>> [<ffffffffa039d086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
>>>> [<ffffffffa01dca86>] ib_unregister_device+0x46/0x120 [ib_core]
>>>> [<ffffffffa032ddc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
>>>> [<ffffffffa02fb9d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
>>>> [<ffffffffa02fba2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
>>>> [<ffffffffa033f4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
>>>> [<ffffffff810bd6b2>] SyS_delete_module+0x152/0x220
>>>> [<ffffffff811496e4>] ? vm_munmap+0x54/0x70
>>>> [<ffffffff815adca6>] system_call_fastpath+0x1a/0x1f
>>>> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d c3
>>>> 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0> 0f
>>>> c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
>>>> RIP [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>>>> RSP <ffff88105d815d18>
>>>> CR2: 0000000000000003
>>>> ---[ end trace 18e02ff413ac4b9b ]---
>>>> Kernel panic - not syncing: Fatal exception in interrupt
>>>> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
>>>> 0xffffffff80000000-0xffffffff9fffffff)
>>>> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>>>>
>>>> Kind regards,
>>>> Klemens
>>>>
>>>> --
>>>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
>>>> the body of a message to [email protected]
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
>>> the body of a message to [email protected]
>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html


2014-05-08 15:59:30

by Anna Schumaker

[permalink] [raw]
Subject: Re: Soft lockup in unloading kernel modules

I haven't applied Chuck's recent (v3) patches to that kernel yet (I've been waiting to see if people have comments). I'll try to push something out today.

On 05/08/2014 10:28 AM, Senn Klemens wrote:
> Hi,
>
> I am getting a soft lockup on the NFS server on its reboot if at least
> one client mount is established. I am using OpenSUSE 12.3 with the
> nfs-rdma kernel from Anna Schumaker
> (git://git.linux-nfs.org/projects/anna/nfs-rdma.git).
>
> The export on the server side is done with
> /data *(fsid=0,crossmnt,rw,mp,no_root_squash,sync,no_subtree_check,insecure)
>
> Following command is used for mounting the NFSv4 share:
> mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.19:/ /mnt
>
> The HCA is a Mellanox MT4099 on the server and the client.
>
> The soft lockup can be reproduced by following steps:
> o server: Start the nfs server
> o client: Mount the share
> o client: Do a "ls" in the mounted directory
> o server: Stop the nfs server
> o server: Unload the nfs and mlx4 modules or reboot the server (I used
> the openibd init script from the Mellanox driver without having the
> Mellanox stack installed)
>
> The server reports a soft lockup
> BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:6146]
> most times.
>
> Sometimes I get following kernel panic
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
> IP: [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
> PGD 82a820067 PUD 857832067 PMD 0
> Oops: 0002 [#1] SMP
> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry nfnetlink_log
> nfnetlink bluetooth rfkill nfsv4 svcrdma dm_mod cpuid nfs fscache lockd
> sunrpc af_packet 8021q garp stp llc rdma_ucm ib_ucm rdma_cm iw_cm
> ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en mlx4_ib(-) ib_sa ib_mad ib_core
> ib_addr sr_mod cdrom usb_storage joydev mlx4_core usbhid
> x86_pkg_temp_thermal coretemp kvm_intel kvm ghash_clmulni_intel
> aesni_intel ablk_helper cryptd iTCO_wdt lrw igb gf128mul
> iTCO_vendor_support ehci_pci glue_helper pcspkr i2c_algo_bit isci
> ehci_hcd aes_x86_64 ptp libsas ioatdma lpc_ich microcode sb_edac sg
> pps_core usbcore ipmi_si tpm_tis edac_core scsi_transport_sas i2c_i801
> mfd_core dca usb_common tpm ipmi_msghandler wmi acpi_cpufreq button edd
> autofs4 xfs libcrc32c crc32c_intel processor thermal_sys scsi_dh_rdac
> scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh [last unloaded: oid_registry]
> CPU: 0 PID: 6603 Comm: modprobe Not tainted 3.15.0-rc2-anna-nfs-rdma+ #3
> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
> task: ffff88105b8c6050 ti: ffff88105d814000 task.ti: ffff88105d814000
> RIP: 0010:[<ffffffff815a5c35>] [<ffffffff815a5c35>]
> _raw_spin_lock_bh+0x15/0x40
> RSP: 0018:ffff88105d815d18 EFLAGS: 00010286
> RAX: 0000000000010000 RBX: ffffffffffffffff RCX: 0000000000000000
> RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000003
> RBP: ffff88105d815d18 R08: ffff88087c611f38 R09: 0000000000000001
> R10: 0000000000000000 R11: 0000000000000000 R12: ffff88087c3c9800
> R13: ffff88107b82ab00 R14: 0000000000000003 R15: 0000000000000007
> FS: 00007fef64612700(0000) GS:ffff88087fc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000003 CR3: 000000087c2c7000 CR4: 00000000000407f0
> Stack:
> ffff88105d815d58 ffffffffa05199f0 ffff88105d815d88 ffff88087c3c9800
> ffff88087c3c9400 ffff88107b82ab00 ffff88087c3c9660 ffff88087c3c95c8
> ffff88105d815d78 ffffffffa0421ce9 ffff88087c3c9400 ffff88107b82aac0
> Call Trace:
> [<ffffffffa05199f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
> [<ffffffffa0421ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
> [<ffffffffa039d086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
> [<ffffffffa01dca86>] ib_unregister_device+0x46/0x120 [ib_core]
> [<ffffffffa032ddc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
> [<ffffffffa02fb9d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
> [<ffffffffa02fba2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
> [<ffffffffa033f4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
> [<ffffffff810bd6b2>] SyS_delete_module+0x152/0x220
> [<ffffffff811496e4>] ? vm_munmap+0x54/0x70
> [<ffffffff815adca6>] system_call_fastpath+0x1a/0x1f
> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d c3
> 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0> 0f
> c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
> RIP [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
> RSP <ffff88105d815d18>
> CR2: 0000000000000003
> ---[ end trace 18e02ff413ac4b9b ]---
> Kernel panic - not syncing: Fatal exception in interrupt
> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
> 0xffffffff80000000-0xffffffff9fffffff)
> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>
> Kind regards,
> Klemens
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html


2014-05-13 16:48:49

by Klemens Senn

[permalink] [raw]
Subject: Re: Soft lockup in unloading kernel modules

Hi Anna,

today I retried unloading the kernel modules with your updated kernel
and additionally I tried the nfsd-next kernel from J. Bruce Fields and
Chuck's nfs-rdma-client kernel.

In short: None of these was able to unload the kernel modules with an
active connection.

In detail:

With your kernel I got following 3 faults:
o BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:4615]
o BUG: unable to handle kernel NULL pointer dereference at
0000000000000003
o BUG: unable to handle kernel paging request at 0000000000005b8c

With the nfsd-next kernel I got following results:
o BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:4452]
o module unloading blocks forever, dmesg shows:
nfsd: last server has exited, flushing export cache
waiting module removal not supported: please upgrade
o Kernel keeps running but reports the following:
nfsd: last server has exited, flushing export cache
waiting module removal not supported: please upgrade
svc_xprt_enqueue: threads and transports both waiting??
INFO: task modprobe:4510 blocked for more than 480 seconds.
Not tainted 3.15.0-rc1-bfields-master+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
modprobe D ffff88087fc13440 0 4510 4458 0x00000000
ffff88105bb23c58 0000000000000086 ffff88105c14e690 0000000000013440
ffff88105bb23fd8 0000000000013440 ffffffff81a14480 ffff88105c14e690
0000000000000037 ffff88085d7f74d8 ffff88085d7f74e0 7fffffffffffffff
Call Trace:
[<ffffffff815a2424>] schedule+0x24/0x70
[<ffffffff815a18cc>] schedule_timeout+0x1ec/0x260
[<ffffffff8159a504>] ? printk+0x5c/0x5e
[<ffffffff815a3406>] wait_for_completion+0x96/0x100
[<ffffffff81080c90>] ? try_to_wake_up+0x2b0/0x2b0
[<ffffffffa0314039>] cma_remove_one+0x1a9/0x220 [rdma_cm]
[<ffffffffa01fea86>] ib_unregister_device+0x46/0x120 [ib_core]
[<ffffffffa02c5dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
[<ffffffffa04319d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
[<ffffffffa0431a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
[<ffffffffa02d74cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
[<ffffffff810bd612>] SyS_delete_module+0x152/0x220
[<ffffffff81149684>] ? vm_munmap+0x54/0x70
[<ffffffff815ad5a6>] system_call_fastpath+0x1a/0x1f

With the nfs-rdma-client I got following results:
o module unloading blocks forever, dmesg shows:
nfsd: last server has exited, flushing export cache
svc_xprt_enqueue: threads and transports both waiting??
o BUG: unable to handle kernel paging request at 0000000000004dec
IP: [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
PGD 107ba9a067 PUD 105c093067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry svcrdma
dm_mod cpuid nfs fscache lockd sunrpc af_packet 8021q garp stp llc
rdma_ucm ib_ucm rdma_cm iw_cm ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en
mlx4_ib(-) ib_sa ib_mad ib_core ib_addr sr_mod cdrom usb_storage joydev
mlx4_core usbhid x86_pkg_temp_thermal coretemp kvm_intel kvm
ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul
glue_helper ehci_pci aes_x86_64 ehci_hcd isci iTCO_wdt libsas pcspkr
iTCO_vendor_support igb i2c_algo_bit sb_edac lpc_ich edac_core ioatdma
usbcore tpm_tis ptp microcode i2c_i801 sg mfd_core scsi_transport_sas
ipmi_si usb_common tpm wmi pps_core dca ipmi_msghandler acpi_cpufreq
button edd autofs4 xfs libcrc32c crc32c_intel processor thermal_sys
scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh
CPU: 14 PID: 4813 Comm: modprobe Not tainted
3.15.0-rc5-cel-nfs-rdma-client-unpatched+ #2
Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
task: ffff88085bf96190 ti: ffff88085d42a000 task.ti: ffff88085d42a000
RIP: 0010:[<ffffffff815a63b5>] [<ffffffff815a63b5>]
_raw_spin_lock_bh+0x15/0x40
RSP: 0018:ffff88085d42bd18 EFLAGS: 00010286
RAX: 0000000000010000 RBX: 0000000000004de8 RCX: 0000000000000000
RDX: 000000000000000b RSI: 000000000000000e RDI: 0000000000004dec
RBP: ffff88085d42bd18 R08: ffff88087c611f38 R09: 000000000000a140
R10: 000000000000002b R11: 0000000000000000 R12: ffff88085dcc3c00
R13: ffff88105ca13280 R14: 0000000000004dec R15: 0000000000004df0
FS: 00007f0e49fb5700(0000) GS:ffff88107fcc0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000004dec CR3: 000000105b027000 CR4: 00000000000407e0
Stack:
ffff88085d42bd58 ffffffffa03bd9f0 0000000001328b88 ffff88085dcc3c00
ffff88085dce8000 ffff88105ca13280 ffff88085dce8260 ffff88085dce81c8
ffff88085d42bd78 ffffffffa0441ce9 ffff88085dce8000 ffff88105ca13240
Call Trace:
[<ffffffffa03bd9f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
[<ffffffffa0441ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
[<ffffffffa031a086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
[<ffffffffa0261a86>] ib_unregister_device+0x46/0x120 [ib_core]
[<ffffffffa02b9dc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
[<ffffffffa02329d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
[<ffffffffa0232a2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
[<ffffffffa02cb4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
[<ffffffff810bd6f0>] SyS_delete_module+0x170/0x1f0
[<ffffffff811497f4>] ? vm_munmap+0x54/0x70
[<ffffffff815ae426>] system_call_fastpath+0x1a/0x1f
Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d
c3 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0>
0f c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
RIP [<ffffffff815a63b5>] _raw_spin_lock_bh+0x15/0x40
RSP <ffff88085d42bd18>
CR2: 0000000000004dec
---[ end trace bf1fd548a33cbfc4 ]---
Kernel panic - not syncing: Fatal exception in interrupt
Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffff9fffffff)
---[ end Kernel panic - not syncing: Fatal exception in interrupt


Regards,
Klemens


On 05/08/2014 05:59 PM, Anna Schumaker wrote:
> I haven't applied Chuck's recent (v3) patches to that kernel yet (I've been waiting to see if people have comments). I'll try to push something out today.
>
> On 05/08/2014 10:28 AM, Senn Klemens wrote:
>> Hi,
>>
>> I am getting a soft lockup on the NFS server on its reboot if at least
>> one client mount is established. I am using OpenSUSE 12.3 with the
>> nfs-rdma kernel from Anna Schumaker
>> (git://git.linux-nfs.org/projects/anna/nfs-rdma.git).
>>
>> The export on the server side is done with
>> /data *(fsid=0,crossmnt,rw,mp,no_root_squash,sync,no_subtree_check,insecure)
>>
>> Following command is used for mounting the NFSv4 share:
>> mount -t nfs -o port=20049,rdma,vers=4.0,timeo=900 172.16.100.19:/ /mnt
>>
>> The HCA is a Mellanox MT4099 on the server and the client.
>>
>> The soft lockup can be reproduced by following steps:
>> o server: Start the nfs server
>> o client: Mount the share
>> o client: Do a "ls" in the mounted directory
>> o server: Stop the nfs server
>> o server: Unload the nfs and mlx4 modules or reboot the server (I used
>> the openibd init script from the Mellanox driver without having the
>> Mellanox stack installed)
>>
>> The server reports a soft lockup
>> BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:6146]
>> most times.
>>
>> Sometimes I get following kernel panic
>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
>> IP: [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>> PGD 82a820067 PUD 857832067 PMD 0
>> Oops: 0002 [#1] SMP
>> Modules linked in: nfsd nfs_acl auth_rpcgss oid_registry nfnetlink_log
>> nfnetlink bluetooth rfkill nfsv4 svcrdma dm_mod cpuid nfs fscache lockd
>> sunrpc af_packet 8021q garp stp llc rdma_ucm ib_ucm rdma_cm iw_cm
>> ib_ipoib ib_cm ib_uverbs ib_umad mlx4_en mlx4_ib(-) ib_sa ib_mad ib_core
>> ib_addr sr_mod cdrom usb_storage joydev mlx4_core usbhid
>> x86_pkg_temp_thermal coretemp kvm_intel kvm ghash_clmulni_intel
>> aesni_intel ablk_helper cryptd iTCO_wdt lrw igb gf128mul
>> iTCO_vendor_support ehci_pci glue_helper pcspkr i2c_algo_bit isci
>> ehci_hcd aes_x86_64 ptp libsas ioatdma lpc_ich microcode sb_edac sg
>> pps_core usbcore ipmi_si tpm_tis edac_core scsi_transport_sas i2c_i801
>> mfd_core dca usb_common tpm ipmi_msghandler wmi acpi_cpufreq button edd
>> autofs4 xfs libcrc32c crc32c_intel processor thermal_sys scsi_dh_rdac
>> scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh [last unloaded: oid_registry]
>> CPU: 0 PID: 6603 Comm: modprobe Not tainted 3.15.0-rc2-anna-nfs-rdma+ #3
>> Hardware name: Supermicro B9DRG-E/B9DRG-E, BIOS 3.0 09/04/2013
>> task: ffff88105b8c6050 ti: ffff88105d814000 task.ti: ffff88105d814000
>> RIP: 0010:[<ffffffff815a5c35>] [<ffffffff815a5c35>]
>> _raw_spin_lock_bh+0x15/0x40
>> RSP: 0018:ffff88105d815d18 EFLAGS: 00010286
>> RAX: 0000000000010000 RBX: ffffffffffffffff RCX: 0000000000000000
>> RDX: 000000000000000b RSI: 0000000000000000 RDI: 0000000000000003
>> RBP: ffff88105d815d18 R08: ffff88087c611f38 R09: 0000000000000001
>> R10: 0000000000000000 R11: 0000000000000000 R12: ffff88087c3c9800
>> R13: ffff88107b82ab00 R14: 0000000000000003 R15: 0000000000000007
>> FS: 00007fef64612700(0000) GS:ffff88087fc00000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 0000000000000003 CR3: 000000087c2c7000 CR4: 00000000000407f0
>> Stack:
>> ffff88105d815d58 ffffffffa05199f0 ffff88105d815d88 ffff88087c3c9800
>> ffff88087c3c9400 ffff88107b82ab00 ffff88087c3c9660 ffff88087c3c95c8
>> ffff88105d815d78 ffffffffa0421ce9 ffff88087c3c9400 ffff88107b82aac0
>> Call Trace:
>> [<ffffffffa05199f0>] svc_xprt_enqueue+0x50/0x220 [sunrpc]
>> [<ffffffffa0421ce9>] rdma_cma_handler+0x69/0x180 [svcrdma]
>> [<ffffffffa039d086>] cma_remove_one+0x1f6/0x220 [rdma_cm]
>> [<ffffffffa01dca86>] ib_unregister_device+0x46/0x120 [ib_core]
>> [<ffffffffa032ddc9>] mlx4_ib_remove+0x29/0x260 [mlx4_ib]
>> [<ffffffffa02fb9d0>] mlx4_remove_device+0xa0/0xc0 [mlx4_core]
>> [<ffffffffa02fba2b>] mlx4_unregister_interface+0x3b/0xa0 [mlx4_core]
>> [<ffffffffa033f4cc>] mlx4_ib_cleanup+0x10/0x23 [mlx4_ib]
>> [<ffffffff810bd6b2>] SyS_delete_module+0x152/0x220
>> [<ffffffff811496e4>] ? vm_munmap+0x54/0x70
>> [<ffffffff815adca6>] system_call_fastpath+0x1a/0x1f
>> Code: 5d c3 0f b7 17 66 39 ca 74 f6 f3 90 0f b7 17 66 39 d1 75 f6 5d c3
>> 55 65 81 04 25 20 b9 00 00 00 02 00 00 48 89 e5 b8 00 00 01 00 <f0> 0f
>> c1 07 89 c2 c1 ea 10 66 39 c2 75 04 5d c3 f3 90 0f b7 07
>> RIP [<ffffffff815a5c35>] _raw_spin_lock_bh+0x15/0x40
>> RSP <ffff88105d815d18>
>> CR2: 0000000000000003
>> ---[ end trace 18e02ff413ac4b9b ]---
>> Kernel panic - not syncing: Fatal exception in interrupt
>> Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range:
>> 0xffffffff80000000-0xffffffff9fffffff)
>> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>>
>> Kind regards,
>> Klemens
>>
>> --
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