Comment # 11 on bug 1200487 from Jiri Slaby

(In reply to Mel Gorman from comment #10)
> Results show some small improvements for some workloads and at least one
> functional failure. The mmtests configuration that failed is
> functional-ltp-cve-xfs for the pty03. The other tests were not complete as I
> write this as the machine had frozen but will be started shortly. The dmesg
> for the failure was
> 
> [ 2465.240179] INFO: task pty03:10270 blocked for more than 491 seconds.
> [ 2465.240188]       Tainted: G            E     5.18.4-lto-enabled #1
> [ 2465.240192] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables
> this message.
> [ 2465.240195] task:pty03           state:D stack:    0 pid:10270 ppid:    
> 1 flags:0x00004004
> [ 2465.240204] Call Trace:
> [ 2465.240207]  <TASK>
> [ 2465.240212]  __schedule+0x344/0x12e0
> [ 2465.240231]  ? number+0x349/0x400
> [ 2465.240242]  schedule+0x5b/0xd0
> [ 2465.240249]  schedule_timeout+0x9f/0xd0
> [ 2465.240260]  wait_for_completion+0x7d/0x130
> [ 2465.240267]  devtmpfs_delete_node+0xc7/0x100
> [ 2465.240276]  ? kernfs_put+0x107/0x1c0
> [ 2465.240290]  device_del+0x408/0x4f0
> [ 2465.240304]  ? class_find_device+0xde/0x1a0
> [ 2465.240313]  device_unregister+0xe/0x60
> [ 2465.240320]  tty_unregister_device+0x5c/0xc0
> [ 2465.240335]  gsmld_close+0x41/0xc0 [n_gsm
> 3758e2ed62c48c2b7e0f63935531528aa58bfb68]

I'm afraid this is a consequence of 5.18 changes in n_gsm done by D. Starke.
We've exchanged few messages with him, but he is unable to reproduce. I'm not
sure anyone cares about n_gsm except him. Maybe Siemens is trying to resurrect
it...

So the easiest way to work around this is simply disabling CONFIG_N_GSM --
would it be possible to restart the functional tests without n_gsm?

> [ 2465.240348]  tty_ldisc_hangup+0x131/0x240
> [ 2465.240358]  __tty_hangup+0x1f3/0x370
> [ 2465.240366]  tty_ioctl+0x74e/0x9d0

...

> Otherwise it was marginal differences.

Thanks for the measurements. I'm a bit surprised there are any differences.
I'll look into the results more deeply.