Re: Urgent Bug report: PPPoE ioctl(PPPIOCCONNECT): Transport endpoint is not connected

Hi 
Sorry for delay but not easy to catch moment .


See this is mpstatl 1 :

Linux 5.14.1 (demobng) 	09/07/21 	_x86_64_	(12 CPU)

11:12:16     CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal  %guest  %gnice   %idle
11:12:17     all    0.17    0.00    6.66    0.00    0.00    4.13    0.00    0.00    0.00   89.05
11:12:18     all    0.25    0.00    8.36    0.00    0.00    4.88    0.00    0.00    0.00   86.51
11:12:19     all    0.26    0.00    9.62    0.00    0.00    3.91    0.00    0.00    0.00   86.21
11:12:20     all    0.85    0.00    6.00    0.00    0.00    4.31    0.00    0.00    0.00   88.84
11:12:21     all    0.08    0.00    4.45    0.00    0.00    4.79    0.00    0.00    0.00   90.67
11:12:22     all    0.17    0.00    9.50    0.00    0.00    4.58    0.00    0.00    0.00   85.75
11:12:23     all    0.00    0.00    6.92    0.00    0.00    2.48    0.00    0.00    0.00   90.61
11:12:24     all    0.17    0.00    5.45    0.00    0.00    4.27    0.00    0.00    0.00   90.11
11:12:25     all    0.25    0.00    5.38    0.00    0.00    4.79    0.00    0.00    0.00   89.58
11:12:26     all    0.60    0.00    1.45    0.00    0.00    2.65    0.00    0.00    0.00   95.30
11:12:27     all    0.42    0.00    6.91    0.00    0.00    4.47    0.00    0.00    0.00   88.20
11:12:28     all    0.00    0.00    6.75    0.00    0.00    4.18    0.00    0.00    0.00   89.07
11:12:29     all    0.17    0.00    3.52    0.00    0.00    5.11    0.00    0.00    0.00   91.20
11:12:30     all    1.45    0.00   10.14    0.00    0.00    3.49    0.00    0.00    0.00   84.92
11:12:31     all    0.09    0.00    5.11    0.00    0.00    4.77    0.00    0.00    0.00   90.03
11:12:32     all    0.25    0.00    3.11    0.00    0.00    4.46    0.00    0.00    0.00   92.17
Average:     all    0.32    0.00    6.21    0.00    0.00    4.21    0.00    0.00    0.00   89.26


I attache and one screenshot from perf top (Screenshot is send on preview mail)

And I see in lsmod 

pppoe                  20480  8198
pppox                  16384  1 pppoe
ppp_generic            45056  16364 pppox,pppoe
slhc                   16384  1 ppp_generic

To slow remove pppoe session .

And from log : 

[2021-09-07 11:01:11.129] vlan3020: ebdd1c5d8b5900f6: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:01:53.621] vlan643: ebdd1c5d8b59014e: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:00.359] vlan1616: ebdd1c5d8b590195: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:05.859] vlan3020: ebdd1c5d8b5900d8: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:08.258] vlan3005: ebdd1c5d8b590190: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:13.820] vlan643: ebdd1c5d8b590152: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:15.839] vlan727: ebdd1c5d8b590144: ioctl(PPPIOCCONNECT): Transport endpoint is not connected
[2021-09-07 11:02:20.139] vlan1693: ebdd1c5d8b59019f: ioctl(PPPIOCCONNECT): Transport endpoint is not connected

On 11 Aug 2021, at 19:48, Guillaume Nault [off-list ref] wrote:

On Wed, Aug 11, 2021 at 02:10:32PM +0300, Martin Zaharinov wrote:

quoted

And one more that see.

Problem is come when accel start finishing sessions,
Now in server have 2k users and restart on one of vlans 3 Olt with 400 users and affect other vlans ,
And problem is start when start destroying dead sessions from vlan with 3 Olt and this affect all other vlans.
May be kernel destroy old session slow and entrained other users by locking other sessions.
is there a way to speed up the closing of stopped/dead sessions.

What are the CPU stats when that happen? Is it users space or kernel
space that keeps it busy?

One easy way to check is to run "mpstat 1" for a few seconds when the
problem occurs.