Re: FYI for aarch64 main [14] running a mid March version: I ended up with [usb{usbus2}] stuck at (near) 100% cpu
Date: Fri, 14 May 2021 21:51:27 UTC
On 2021-May-14, at 13:48, Rodney W. Grimes <freebsd-rwg at gndrsh.dnsmgr.net> wrote:
>>
>> On 2021-May-14, at 05:52, Rodney W. Grimes <freebsd-rwg at gndrsh.dnsmgr.net> wrote:
>>
>>>> Note: The context was using a non-debug main build
>>>> from mid-2021-Mar. (More details identified
>>>> later.)
>>>>
>>>> The issue happend while attempting a:
>>>>
>>>> # zfs send -R zpold@for-copy | zfs recv -Fdv zpnew
>>>>
>>>> where the drives involved in the command were:
>>>>
>>>> zpold: a USB3 SSD, using /dev/da0p3
>>>> zpnew: an 480 GiByte Optane in the PCIe slot, using /dev/nda0p3
>>>>
>>>> with:
>>>>
>>>> # gpart show -pl
>>>> => 40 468862048 da0 GPT (224G)
>>>> 40 532480 da0p1 4C8GCA72EFI (260M)
>>>> 532520 2008 - free - (1.0M)
>>>> 534528 29360128 da0p2 4C8GCA72swp14 (14G)
>>>> 29894656 4194304 - free - (2.0G)
>>>> 34088960 33554432 da0p4 4C8GCA72swp16 (16G)
>>>> 67643392 401217536 da0p3 4C8GCA72zfs (191G)
>>>> 468860928 1160 - free - (580K)
>>>>
>>>> => 40 2000409184 ada0 GPT (954G)
>>>> 40 409600 ada0p1 (null) (200M)
>>>> 409640 1740636160 ada0p2 FBSDmacchroot (830G)
>>>> 1741045800 58720256 ada0p3 FBSDmacchswp0 (28G)
>>>> 1799766056 176160768 ada0p4 FBSDmacchswp1 (84G)
>>>> 1975926824 24482400 - free - (12G)
>>>>
>>>> => 40 937703008 nda0 GPT (447G)
>>>> 40 532480 nda0p1 CA72opt0EFI (260M)
>>>> 532520 2008 - free - (1.0M)
>>>> 534528 117440512 nda0p2 CA72opt0swp56 (56G)
>>>> 117975040 16777216 - free - (8.0G)
>>>> 134752256 134217728 nda0p4 CA72opt0swp64 (64G)
>>>> 268969984 668731392 nda0p3 CA72opt0zfs (319G)
>>>> 937701376 1672 - free - (836K)
>>>>
>>>> The system running was that on /dev/ada0p2 (FBSDmacchroot,
>>>> which is UFS instead of ZFS).
>>>>
>>>> The [usb{usbus2}] process eventually got stuck-busy, no
>>>> more I/O:
>>>>
>>>> CPU 0: 0.0% user, 0.0% nice, 100% system, 0.0% interrupt, 0.0% idle
>>>> CPU 1: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle
>>>> CPU 2: 0.0% user, 0.0% nice, 0.0% system, 0.0% interrupt, 100% idle
>>>> CPU 3: 0.4% user, 0.0% nice, 0.0% system, 0.0% interrupt, 99.6% idle
>>>>
>>>> PID USERNAME PRI NICE SIZE RES STATE C TIME CPU COMMAND
>>>> 15 root -72 - 0B 262144B CPU0 0 8:51 99.95% [usb{usbus2}]
>>>>
>>>> 1295 root -8 0 20108Ki 8092Ki q->bq_ 2 0:04 0.00% zfs recv -Fdv zpnew{receive_writer_thre}
>>>> 1295 root 48 0 20108Ki 8092Ki piperd 2 0:22 0.00% zfs recv -Fdv zpnew{zfs}
>>>> 1294 root -8 0 17544Ki 7740Ki q->bq_ 2 0:01 0.00% zfs send -R zpold@for-copy{send_reader_thread}
>>>> 1294 root -8 0 17544Ki 7740Ki q->bq_ 0 0:00 0.00% zfs send -R zpold@for-copy{send_merge_thread}
>>>> 1294 root -8 0 17544Ki 7740Ki hdr->b 2 0:00 0.00% zfs send -R zpold@for-copy{send_traverse_threa}
>>>> 1294 root 52 0 17544Ki 7740Ki range- 3 0:20 0.00% zfs send -R zpold@for-copy{zfs}
>>>>
>>>> 1036 root -8 - 0B 1488Ki t->zth 0 0:00 0.00% [zfskern{z_checkpoint_discar}]
>>>> 1036 root -8 - 0B 1488Ki t->zth 1 0:00 0.00% [zfskern{z_livelist_condense}]
>>>> 1036 root -8 - 0B 1488Ki t->zth 2 0:00 0.00% [zfskern{z_livelist_destroy}]
>>>> 1036 root -8 - 0B 1488Ki t->zth 1 0:00 0.00% [zfskern{z_indirect_condense}]
>>>> 1036 root -8 - 0B 1488Ki mmp->m 3 0:00 0.00% [zfskern{mmp_thread_enter}]
>>>> 1036 root -8 - 0B 1488Ki tx->tx 1 0:00 0.00% [zfskern{txg_thread_enter}]
>>>> 1036 root -8 - 0B 1488Ki tx->tx 2 0:00 0.00% [zfskern{txg_thread_enter}]
>>>>
>>>> I was unable to ^c or ^z the process where I
>>>> typed the command. I eventually stopped the
>>>> system with "shutdown -p now" from a ssh
>>>> session (that had already been in place).
>>>
>>> Should this occur again before doing the shutdown run a
>>> zpool status &
>>> I have gotten in this state when the recv pool was a usb device
>>
>> The USB device had the send pool in my example.
>>
>>> and for some reason it had a timeout and gone offline.
>>
>> No messages about timeouts or other such were made.
>>
>>> The clue
>>> this occured are in dmesg, and zpool status.
>>
>> No console, dmesg -a, or /var/log/messages output were
>> generated. (And the system was running from a SATA SSD
>> that was operating well.)
>>
>> For reference, the USB EtherNet device that was in a
>> USB2 port continued to operate just fine, allowing the
>> use of existing ssh sessions that were displaying
>> gstat -spod and top -Samio -ototal until I started
>> looking at the problem. (I did not try making a new
>> ssh session).
>>
>> I did not do the "zpool status" so I can not report
>> about it.
>>
>>> Unplug/plug the USB device, check dmesg that it came online,
>>> and do a zpool clear.
>>
>> Okay. I normally avoid unplugging USB storage media
>> if the system overall does not hang up: hopes of
>> a clean shutdown leaving things better.
>
> Do the zpool status, and only if that indicates a device offline
> or other problem would you proceed to do the unplug/plug, as at
> that point zfs has stopped doing anything to the device and
> your shutdown wont do anything as far as zfs for that pool anyway.
>
>>
>> The system did appear to shutdown to completion.
>
> Yes, you can shutdown a system with a zpool in failed state.
I still have the console output available and I was
wrong: the shutdown hung up and apparently I cut
power before "All buffers synced". All it got to
was:
Stopping cron.
Waiting for PIDS: 858.
Stopping sshd.
Waiting for PIDS: 852.
fstab: /etc/fstab:6: Inappropriate file type or format
Stopping ntpd.
Waiting for PIDS: 807.
Stopping nfsd.
Waiting for PIDS: 781 782.
Stopping mountd.
Waiting for PIDS: 779.
Stopping rpcbind.
Waiting for PIDS: 741.
Stopping devd.
Waiting for PIDS: 431.
Writing entropy file: .
Writing early boot entropy file: .
.
Terminated
May 13 20:16:26 FBSDmacch syslogd: exiting on signal 15
It did not get to any of the usual sort of (from a different
shutdown):
Waiting (max 60 seconds) for system process `vnlru' to stop... done
Waiting (max 60 seconds) for system process `syncer' to stop...
Syncing disks, vnodes remaining... 0 0 0 0 0 0 0 0 0 0 done
Waiting (max 60 seconds) for system thread `bufdaemon' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-1' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-3' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-4' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-5' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-0' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-2' to stop... done
Waiting (max 60 seconds) for system thread `bufspacedaemon-6' to stop... done
All buffers synced.
Uptime: 8m12s
>>
>>>>
>>>> When I retried after rebooting and scrubbing (no
>>>> problems found), the problem did not repeat.
>>>>
>>>> I do not have more information nor a way to repeat
>>>> the problem on demand, unfortunately.
>>>>
>>>> Details of the vintage of the system software and
>>>> such:
>>>>
>>>> # ~/fbsd-based-on-what-freebsd-main.sh
>>>> FreeBSD FBSDmacch 14.0-CURRENT FreeBSD 14.0-CURRENT mm-src-n245445-def0058cc690 GENERIC-NODBG arm64 aarch64 1400005 1400005
>>>> def0058cc690 (HEAD -> mm-src) mm-src snapshot for mm's patched build in git context.
>>>> merge-base: 7381bbee29df959e88ec59866cf2878263e7f3b2
>>>> merge-base: CommitDate: 2021-03-12 20:29:42 +0000
>>>> 7381bbee29df (freebsd/main, freebsd/HEAD, pure-src, main) cam: Run all XPT_ASYNC ccbs in a dedicated thread
>>>> n245444 (--first-parent --count for merge-base)
>>>>
>>>> The system was a MACCHIATObin Double Shot.
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)