Public bug reported:
SRU Justification
[Impact]
Hello Canonical Team,
This issue was found while doing the validation on CPC's Jammy CVM
image. We are up against a tight timeline to deliver this to a partner
on 10/5. Would appreciate prioritizing this.
While running fio, the command fails to exit after 2 minutes. I watched
`top` as the command hung and I saw kworkers getting blocked.
sudo fio --ioengine=libaio --bs=4K
--filename=/dev/sdc1:/dev/sdd1:/dev/sde1:/dev/sdf1:/dev/sdg1:/dev/sdh1:/dev/sdi1:/dev/sdj1:/dev/sdk1:/dev/sdl1:/dev/sdm1:/dev/sdn1:/dev/sdo1:/dev/sdp1:/dev/sdq1:/dev/sdr1
--readwrite=randwrite --runtime=120 --iodepth=1 --numjob=96
--name=iteration9 --direct=1 --size=8192M --group_reporting
--overwrite=1
Example system logs:
---------------------------------------------------------------------------------------------------------------
[ 1096.297641] INFO: task kworker/u192:0:8 blocked for more than 120 seconds.
[ 1096.302785] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.306312] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 1096.310489] INFO: task jbd2/sda1-8:1113 blocked for more than 120 seconds.
[ 1096.313900] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.317481] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
[ 1096.324117] INFO: task systemd-journal:1191 blocked for more than 120
seconds.
[ 1096.331219] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.335332] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
---------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------
[ 3241.013230] systemd-udevd[1221]: sdl1: Worker [6686] processing SEQNUM=13323
killed
[ 3261.492691] systemd-udevd[1221]: sdl1: Worker [6686] failed
---------------------------------------------------------------------------------------------------------------
TOP report:
---------------------------------------------------------------------------------------------------------------
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
417 root 20 0 0 0 0 R 66.2 0.0 0:34.61 ksoftirqd/59
435 root 20 0 0 0 0 I 24.5 0.0 0:09.03 kworker/59:1-mm_percpu_wq
416 root rt 0 0 0 0 S 23.5 0.0 0:01.86 migration/59
366 root 0 -20 0 0 0 I 19.2 0.0 0:16.64 kworker/49:1H-kblockd
378 root 0 -20 0 0 0 I 17.9 0.0 0:15.71 kworker/51:1H-kblockd
455 root 0 -20 0 0 0 I 17.9 0.0 0:14.76 kworker/62:1H-kblockd
135 root 0 -20 0 0 0 I 17.5 0.0 0:13.08 kworker/17:1H-kblockd
420 root 0 -20 0 0 0 I 16.9 0.0 0:14.63 kworker/58:1H-kblockd
...
---------------------------------------------------------------------------------------------------------------
LISAv3 Testcase: perf_premium_datadisks_4k
Image : "canonical-test 0001-com-ubuntu-confidential-vm-jammy-preview
22_04-lts-cvm latest"
VMSize : "Standard_DC96ads_v5"
For repro-ability, I am seeing this every time I run the storage perf
tests. It always seems to happen on iteration 9 or 10. When running
manually, I had to run the command three or four times to reproduce the
issue.
[Test Case]
Microsoft tested, requires lots of cores (96) and disks (16)
[Where things could go wrong]
swiotlb buffers could be double freed.
[Other Info]
SF: #00349781
** Affects: linux-azure (Ubuntu)
Importance: Undecided
Status: New
** Affects: linux-azure (Ubuntu Jammy)
Importance: Critical
Assignee: Tim Gardner (timg-tpi)
Status: In Progress
** Affects: linux-azure (Ubuntu Kinetic)
Importance: Undecided
Status: New
** Package changed: linux (Ubuntu) => linux-azure (Ubuntu)
** Also affects: linux-azure (Ubuntu Kinetic)
Importance: Undecided
Status: New
** Also affects: linux-azure (Ubuntu Jammy)
Importance: Undecided
Status: New
** Changed in: linux-azure (Ubuntu Jammy)
Importance: Undecided => Critical
** Changed in: linux-azure (Ubuntu Jammy)
Status: New => In Progress
** Changed in: linux-azure (Ubuntu Jammy)
Assignee: (unassigned) => Tim Gardner (timg-tpi)
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1998838
Title:
Azure: Jammy fio test hangs, swiotlb buffers exhausted
Status in linux-azure package in Ubuntu:
New
Status in linux-azure source package in Jammy:
In Progress
Status in linux-azure source package in Kinetic:
New
Bug description:
SRU Justification
[Impact]
Hello Canonical Team,
This issue was found while doing the validation on CPC's Jammy CVM
image. We are up against a tight timeline to deliver this to a partner
on 10/5. Would appreciate prioritizing this.
While running fio, the command fails to exit after 2 minutes. I
watched `top` as the command hung and I saw kworkers getting blocked.
sudo fio --ioengine=libaio --bs=4K
--filename=/dev/sdc1:/dev/sdd1:/dev/sde1:/dev/sdf1:/dev/sdg1:/dev/sdh1:/dev/sdi1:/dev/sdj1:/dev/sdk1:/dev/sdl1:/dev/sdm1:/dev/sdn1:/dev/sdo1:/dev/sdp1:/dev/sdq1:/dev/sdr1
--readwrite=randwrite --runtime=120 --iodepth=1 --numjob=96
--name=iteration9 --direct=1 --size=8192M --group_reporting
--overwrite=1
Example system logs:
---------------------------------------------------------------------------------------------------------------
[ 1096.297641] INFO: task kworker/u192:0:8 blocked for more than 120 seconds.
[ 1096.302785] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.306312] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[ 1096.310489] INFO: task jbd2/sda1-8:1113 blocked for more than 120 seconds.
[ 1096.313900] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.317481] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
[ 1096.324117] INFO: task systemd-journal:1191 blocked for more than 120
seconds.
[ 1096.331219] Tainted: G W 5.15.0-1024-azure #30-Ubuntu
[ 1096.335332] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
this message.
---------------------------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------------------------
[ 3241.013230] systemd-udevd[1221]: sdl1: Worker [6686] processing
SEQNUM=13323 killed
[ 3261.492691] systemd-udevd[1221]: sdl1: Worker [6686] failed
---------------------------------------------------------------------------------------------------------------
TOP report:
---------------------------------------------------------------------------------------------------------------
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
417 root 20 0 0 0 0 R 66.2 0.0 0:34.61 ksoftirqd/59
435 root 20 0 0 0 0 I 24.5 0.0 0:09.03 kworker/59:1-mm_percpu_wq
416 root rt 0 0 0 0 S 23.5 0.0 0:01.86 migration/59
366 root 0 -20 0 0 0 I 19.2 0.0 0:16.64 kworker/49:1H-kblockd
378 root 0 -20 0 0 0 I 17.9 0.0 0:15.71 kworker/51:1H-kblockd
455 root 0 -20 0 0 0 I 17.9 0.0 0:14.76 kworker/62:1H-kblockd
135 root 0 -20 0 0 0 I 17.5 0.0 0:13.08 kworker/17:1H-kblockd
420 root 0 -20 0 0 0 I 16.9 0.0 0:14.63 kworker/58:1H-kblockd
...
---------------------------------------------------------------------------------------------------------------
LISAv3 Testcase: perf_premium_datadisks_4k
Image : "canonical-test 0001-com-ubuntu-confidential-vm-jammy-preview
22_04-lts-cvm latest"
VMSize : "Standard_DC96ads_v5"
For repro-ability, I am seeing this every time I run the storage perf
tests. It always seems to happen on iteration 9 or 10. When running
manually, I had to run the command three or four times to reproduce
the issue.
[Test Case]
Microsoft tested, requires lots of cores (96) and disks (16)
[Where things could go wrong]
swiotlb buffers could be double freed.
[Other Info]
SF: #00349781
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