White screen when connecting after one day

[jnko]

Hi

I’m running NX server 6.3.6 on a Linux machine and everything runs fine for a while. But after one or two days NX suddenly stops working. I can still logon but the client shows a white screen only – regardless which client I use (Windows, Linux, Android). Every component is on the latest version available.

The NX machine itself still runs fine without any problems. After restarting the whole machine NX will run for one or two days again…

I’ve attached NX logfiles with debugging enabled. If you need additional logs or something else I’d be glad to help.

Any idea what’s going on?

Thanks in advance

jnko

 

[Britgirl]

Hi, the logs didn’t attach (they might have been too big). Can you try sending them directly to forum[at]nomachine[dot]com?

[jnko]

Sure, they’re on the way.

[brotech]

Hello jnko,

could you please send also NX/var/log/node directory from server side, and
.nx from nxplayer side ?

Regards

[jnko]

Here they are.

Attachments:

1. logs.zip

[jnko]

Since I’m using the enterprise client there are no logs. I there is some switch to enable client logs, please let me know. But I strongly guess that this is no client related problem because it does not work in Linux- nor Android nor Windows client.

 

The interesting info seems to be on node/C*/session file – This was exactly the moment where it failed.

Info: Screen capture running with pid 30734.
Session: Connected to display server ‘:0’ at ‘Wed Oct 24 09:57:17 2018’.
Session: Connected to events server ‘:0’ at ‘Wed Oct 24 09:57:17 2018’.
Info: Using damage extension for screen updates.
Info: Screen analysis running with pid 30735.
Info: Using grab method ‘CopyArea’.
Info: Using screen size 1600×900.
Info: RT handler running with pid 30755.
Info: Display server for 166BC9550FD75BA6F74F40C8F17261CE connected on Wed Oct 24 09:57:17 2018.
Info: Audio server for 166BC9550FD75BA6F74F40C8F17261CE connected on Wed Oct 24 09:57:17 2018.
Info: Audio client for 166BC9550FD75BA6F74F40C8F17261CE connected on Wed Oct 24 09:57:17 2018.
913 30734 09:57:17 690.110 DisplayEncoder/DisplayEncoder: ERROR! Failed to encode H.264 frame.
Info: Using Vp8 software encoder.
Info: Audio reader running with pid 30793.
913 30734 09:57:50 673.895 Writer/Writer: WARNING! Buffer for FD#30 reached 226905 bytes.
913 30734 09:59:04 502.263 Writer/Writer: WARNING! Buffer for FD#30 reached 174079 bytes.
913 30734 09:59:04 620.045 Writer/Writer: WARNING! Buffer for FD#30 reached 174079 bytes.
913 30734 09:59:19 712.922 Writer/Writer: WARNING! Buffer for FD#30 reached 147033 bytes.
913 30734 09:59:19 867.393 Writer/Writer: WARNING! Buffer for FD#30 reached 147033 bytes.
913 30734 10:01:22 782.142 Writer/Writer: WARNING! Buffer for FD#30 reached 169422 bytes.
913 30734 10:01:40 555.524 Writer/Writer: WARNING! Buffer for FD#30 reached 205466 bytes.
913 30793 10:02:21 481.573 AudioIoPulseaudioClientConnection: WARNING! Shutting down with Pulseaudio connection errors.
913 30734 10:06:27 178.954 Writer/Writer: WARNING! Buffer for FD#30 reached 162945 bytes.
nxagentSharedMemoryInit: WARNING! Failed to allocate shared memory segment of 33554432 bytes.
nxagentSharedMemoryInit: WARNING! Trying to allocate 16777216 bytes.
nxagentSharedMemoryInit: ERROR! Failed to allocate shared memory segment of 16777216 bytes.
nxagentDisplayServerInit: ERROR! Failed to initialize the shared memory.
Info: RT handler running with pid 3308.
Info: Display server for C00B6FE711D383E0E49CA9D28A950A95 connected on Wed Oct 24 10:07:54 2018.
Info: Audio server for C00B6FE711D383E0E49CA9D28A950A95 connected on Wed Oct 24 10:07:54 2018.
Info: Audio client for C00B6FE711D383E0E49CA9D28A950A95 connected on Wed Oct 24 10:07:54 2018.
Info: Audio reader running with pid 3340.
913 930 10:08:43 898.424 DisplayServerApplication/MediaServerApplication: WARNING! Invalid encoder in method ‘removeEncoder’.
nxagentSharedMemoryInit: WARNING! Failed to allocate shared memory segment of 33554432 bytes.
nxagentSharedMemoryInit: WARNING! Trying to allocate 16777216 bytes.
nxagentSharedMemoryInit: ERROR! Failed to allocate shared memory segment of 16777216 bytes.
nxagentDisplayServerInit: ERROR! Failed to initialize the shared memory.

[brotech]

Hello jnko,

it seems that the white screen problem is related to shared memory.
Please share here output of commands:
ipcs -s

sysctl -a | grep shm

top -b -n 1

run through sudo or as root user.

regards

[jnko]

it seems that the white screen problem is related to shared memory.

Yes, of course, but why? It worked well for more than one year but now, suddenly….
Nothing has been changed besides updates from time to time. No new software or config changes.

 

root@l ~# ipcs -s

—— Semaphore Arrays ——–
key        semid      owner      perms      nsems
0xeb01542e 32768      l          600        1
root@l ~# sysctl -a | grep shm
kernel.shm_next_id = -1
kernel.shm_rmid_forced = 0
kernel.shmall = 18446744073692774399
kernel.shmmax = 18446744073692774399
kernel.shmmni = 4096
vm.hugetlb_shm_group = 0

 

root@l ~# top -b -n 1
top – 16:19:34 up 1 day,  4:25,  2 users,  load average: 0.02, 1.55, 1.96
Tasks: 179 total,   1 running, 177 sleeping,   0 stopped,   1 zombie
%Cpu(s):  0.0 us,  0.0 sy,  0.0 ni,100.0 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   7976.6 total,   3042.2 free,    807.0 used,   4127.4 buff/cache
MiB Swap:   2048.0 total,   2048.0 free,      0.0 used.   5561.7 avail Mem

PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
1 root      20   0  215728   9252   7032 S   0.0   0.1   0:00.97 systemd
2 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kthreadd
3 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_gp
4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rcu_par_gp
6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/0:0H-kblockd
8 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_percpu_wq
9 root      20   0       0      0      0 S   0.0   0.0   0:00.71 ksoftirqd/0
10 root      -2   0       0      0      0 I   0.0   0.0   0:05.78 rcu_preempt
11 root      -2   0       0      0      0 I   0.0   0.0   0:01.85 rcu_sched
12 root      -2   0       0      0      0 I   0.0   0.0   0:00.00 rcu_bh
13 root      -2   0       0      0      0 S   0.0   0.0   0:00.85 rcuc/0
14 root      -2   0       0      0      0 S   0.0   0.0   0:00.00 rcub/0
15 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/0
16 root      rt   0       0      0      0 S   0.0   0.0   0:00.07 watchdog/0
17 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/0
18 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/1
19 root      rt   0       0      0      0 S   0.0   0.0   0:00.06 watchdog/1
20 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/1
21 root      -2   0       0      0      0 S   0.0   0.0   0:01.08 rcuc/1
22 root      20   0       0      0      0 S   0.0   0.0   0:01.86 ksoftirqd/1
24 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/1:0H-kblockd
25 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/2
26 root      rt   0       0      0      0 S   0.0   0.0   0:00.07 watchdog/2
27 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/2
28 root      -2   0       0      0      0 S   0.0   0.0   0:00.70 rcuc/2
29 root      20   0       0      0      0 S   0.0   0.0   0:00.45 ksoftirqd/2
31 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/2:0H-kblockd
32 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/3
33 root      rt   0       0      0      0 S   0.0   0.0   0:00.07 watchdog/3
34 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/3
35 root      -2   0       0      0      0 S   0.0   0.0   0:00.61 rcuc/3
36 root      20   0       0      0      0 S   0.0   0.0   0:00.36 ksoftirqd/3
38 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/3:0H
39 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/4
40 root      rt   0       0      0      0 S   0.0   0.0   0:00.07 watchdog/4
41 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/4
42 root      -2   0       0      0      0 S   0.0   0.0   0:00.60 rcuc/4
43 root      20   0       0      0      0 S   0.0   0.0   0:00.34 ksoftirqd/4
45 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/4:0H-kblockd
46 root      20   0       0      0      0 S   0.0   0.0   0:00.00 cpuhp/5
47 root      rt   0       0      0      0 S   0.0   0.0   0:00.07 watchdog/5
48 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 migration/5
49 root      -2   0       0      0      0 S   0.0   0.0   0:00.58 rcuc/5
50 root      20   0       0      0      0 S   0.0   0.0   0:00.33 ksoftirqd/5
51 root      20   0       0      0      0 I   0.0   0.0   0:00.01 kworker/5:0-mm_percpu_wq
52 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/5:0H-kblockd
53 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kdevtmpfs
54 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 netns
55 root      20   0       0      0      0 S   0.0   0.0   0:00.00 rcu_tasks_kthre
56 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kauditd
59 root      20   0       0      0      0 S   0.0   0.0   0:00.03 khungtaskd
60 root      20   0       0      0      0 S   0.0   0.0   0:00.00 oom_reaper
61 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 writeback
62 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kcompactd0
63 root      25   5       0      0      0 S   0.0   0.0   0:00.00 ksmd
64 root      39  19       0      0      0 S   0.0   0.0   0:00.00 khugepaged
65 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 crypto
66 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kintegrityd
67 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kblockd
68 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 edac-poller
69 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 devfreq_wq
70 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 watchdogd
72 root      20   0       0      0      0 I   0.0   0.0   0:00.34 kworker/3:1-mm_percpu_wq
74 root      20   0       0      0      0 I   0.0   0.0   0:00.28 kworker/5:1-cgroup_destroy
76 root      20   0       0      0      0 S   0.0   0.0   0:00.02 kswapd0
117 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kthrotld
118 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 acpi_thermal_pm
119 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 nvme-wq
120 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 nvme-reset-wq
121 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 nvme-delete-wq
122 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 vfio-irqfd-clea
123 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kstrp
136 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 charger_manager
167 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 ata_sff
169 root      20   0       0      0      0 S   0.0   0.0   0:00.00 scsi_eh_0
170 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 scsi_tmf_0
171 root      20   0       0      0      0 S   0.0   0.0   0:00.00 scsi_eh_1
172 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 scsi_tmf_1
175 root      20   0       0      0      0 S   0.0   0.0   0:00.00 scsi_eh_2
176 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 scsi_tmf_2
179 root       0 -20       0      0      0 I   0.0   0.0   0:00.03 kworker/1:1H-kblockd
181 root       0 -20       0      0      0 I   0.0   0.0   0:00.29 kworker/0:1H-kblockd
185 root       0 -20       0      0      0 I   0.0   0.0   0:00.04 kworker/2:1H-kblockd
208 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/5:1H-kblockd
209 root      20   0       0      0      0 S   0.0   0.0   0:00.42 jbd2/sda1-8
210 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 ext4-rsv-conver
218 root       0 -20       0      0      0 I   0.0   0.0   0:00.01 kworker/4:1H-kblockd
230 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/3:1H-kblockd
236 root      20   0  112632  42196  41112 S   0.0   0.5   0:00.47 systemd-journal
245 root      20   0   80296   1464   1328 S   0.0   0.0   0:00.00 lvmetad
255 root      20   0   67188   7032   5712 S   0.0   0.1   0:00.13 systemd-udevd
302 systemd+  20   0  124544   6548   5796 S   0.0   0.1   0:00.10 systemd-timesyn
309 root      20   0    8420   3136   2876 S   0.0   0.0   0:17.20 qemu-ga
311 root      20   0   50332   6112   5332 S   0.0   0.1   0:01.05 systemd-logind
312 dbus      20   0   13016   4464   3360 S   0.0   0.1   0:01.81 dbus-daemon
338 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 cfg80211
397 root      20   0    2812   1516   1192 S   0.0   0.0   0:00.02 dhcpcd
398 root      20   0   20700   5600   4912 S   0.0   0.1   0:00.00 sshd
401 nx        20   0  376164  81932  10732 S   0.0   1.0   1:04.17 nxserver.bin
402 root      20   0  860204  51824  40532 S   0.0   0.6   0:33.53 fail2ban-server
403 l         20   0   60308   8236   6916 S   0.0   0.1   0:00.05 systemd
405 root      20   0  144296  14096  12864 S   0.0   0.2   0:00.00 sddm
413 l         20   0  104284   2228     20 S   0.0   0.0   0:00.00 (sd-pam)
444 nx        20   0  398140   7128   6332 S   0.0   0.1   0:00.01 nxd
470 root      20   0 2042840 992668 925724 S   0.0  12.2  56:09.50 Xorg
489 root      20   0  106752  13812  12484 S   0.0   0.2   0:00.00 sddm-helper
491 l         20   0    9100   3280   2808 S   0.0   0.0   0:00.00 startkde
501 l         20   0   12804   4428   3408 S   0.0   0.1   0:01.61 dbus-daemon
521 l         20   0    4240     84      0 S   0.0   0.0   0:00.00 start_kdeinit
522 l         20   0  127700  19176  16480 S   0.0   0.2   0:00.04 kdeinit5
523 l         20   0  327536  37832  33256 S   0.0   0.5   0:00.89 klauncher
526 l         20   0  864072  43292  36068 S   0.0   0.5   0:03.06 kded5
538 l         20   0  348732  38528  33992 S   0.0   0.5   0:00.69 kaccess
540 l         20   0   56452   7108   6540 S   0.0   0.1   0:00.00 kwrapper5
542 l         20   0  427616  45608  39980 S   0.0   0.6   0:01.93 ksmserver
544 l         20   0  327300  36788  31712 S   0.0   0.5   0:00.70 kglobalaccel5
550 l         20   0  257976  17540  15760 S   0.0   0.2   0:00.54 kscreen_backend
557 root      20   0  286552   8648   7404 S   0.0   0.1   0:00.02 upowerd
558 l         20   0 3271392 105344  82084 S   0.0   1.3   4:16.98 kwin_x11
563 l         20   0  167180   5008   4432 S   0.0   0.1   0:00.00 dconf-service
565 l         20   0  976608  90188  72552 S   0.0   1.1   0:06.37 krunner
567 l         20   0 2082676 223472 121288 S   0.0   2.7   2:39.92 plasmashell
572 l         20   0  486096  39816  35184 S   0.0   0.5   0:00.62 polkit-kde-auth
577 l         20   0  266692  19628  17564 S   0.0   0.2   0:00.61 xembedsniproxy
584 polkitd   20   0 2141000  21272  14672 S   0.0   0.3   0:00.73 polkitd
596 l         20   0  265688  21008  18908 S   0.0   0.3   0:00.55 gmenudbusmenupr
599 l         20   0  899388  89800  72636 S   0.0   1.1   0:14.54 konsole
643 l         20   0  582880  32936  29064 S   0.0   0.4   0:00.78 kactivitymanage
661 l         20   0    8968   2804   2524 S   0.0   0.0   0:00.00 JDStartup
755 l         20   0  939684  87368  56456 S   0.0   1.1   0:01.00 onboard
790 root      20   0  430348  11624   9612 S   0.0   0.1   0:00.08 udisksd
815 l         20   0  320348   6016   5244 S   0.0   0.1   0:00.02 at-spi-bus-laun
822 l         20   0   12268   3688   3280 S   0.0   0.0   0:00.10 dbus-daemon
826 l         20   0  187940   6312   5524 S   0.0   0.1   0:00.61 at-spi2-registr
850 l         20   0  331376  37644  33336 S   0.0   0.5   0:00.66 kuiserver5
853 l         20   0    6324   2196   1936 S   0.0   0.0   0:12.17 ksysguardd
876 root       0 -20   23076   4696   4212 S   0.0   0.1   0:00.00 nxexec
881 l          0 -20 2840584 217952  25788 S   0.0   2.7 153:28.59 nxnode.bin
909 l         20   0 2403620  38816  26900 S   0.0   0.5   0:13.01 nxclient.bin
1087 l         20   0  128612  17148  13908 S   0.0   0.2   0:00.44 file.so
1145 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kdmflush
1150 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kcryptd_io
1151 root       0 -20       0      0      0 I   0.0   0.0   0:00.02 kcryptd
1152 root      20   0       0      0      0 S   0.0   0.0   0:00.46 dmcrypt_write
1168 root      20   0       0      0      0 S   0.0   0.0   0:00.27 jbd2/dm-0-8
1169 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 ext4-rsv-conver
1180 l         20   0   23812  13712   7388 S   0.0   0.2   1:41.31 transcode
1289 l         20   0  232756   6360   4896 S   0.0   0.1   0:00.17 fish
1437 l         20   0 1554724 146736 102776 S   0.0   1.8   4:50.43 doublecmd
1988 root      20   0       0      0      0 I   0.0   0.0   0:02.55 kworker/2:4-events
3442 systemd+  20   0   67748  10136   8116 S   0.0   0.1   0:00.80 systemd-resolve
9868 root      20   0       0      0      0 I   0.0   0.0   0:00.20 kworker/4:2-mm_percpu_wq
9879 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/3:2-cgroup_destroy
11349 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/2:0
16114 l         20   0       0      0      0 Z   0.0   0.0   0:00.00 xdg-open
21159 root      20   0       0      0      0 I   0.0   0.0   0:00.09 kworker/u12:1-flush-254:0
21251 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/1:2-mm_percpu_wq
21345 root       0 -20       0      0      0 I   0.0   0.0   0:00.43 kworker/u13:5-kcryptd
23635 root       0 -20       0      0      0 I   0.0   0.0   0:00.14 kworker/u13:1-kcryptd
24723 root      20   0       0      0      0 I   0.0   0.0   0:00.04 kworker/u12:0-events_unbound
25055 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/0:1-rcu_par_gp
25391 l         20   0   95504  19584  12832 S   0.0   0.2   0:03.23 x11vnc
25493 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/1:0-cgroup_destroy
25714 root      20   0   50128   6456   5568 S   0.0   0.1   0:00.01 sshd
25717 l         20   0   50816   4668   3720 S   0.0   0.1   0:00.04 sshd
25718 l         20   0  159312   7016   5440 S   0.0   0.1   0:00.23 fish
25807 root      20   0       0      0      0 I   0.0   0.0   0:00.16 kworker/u12:2-events_unbound
25927 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/4:0-events
25954 root      20   0       0      0      0 I   0.0   0.0   0:00.00 kworker/0:3-events
25959 root      20   0   50128   6400   5504 S   0.0   0.1   0:00.01 sshd
25962 l         20   0   50812   4992   4036 S   0.0   0.1   0:00.17 sshd
26117 root      20   0   24748   3308   2904 S   0.0   0.0   0:00.00 su
26118 root      20   0  159412   6956   5572 S   0.0   0.1   0:00.10 fish
26197 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/u13:0-kcryptd
26198 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/u13:2-kcryptd
26245 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/u13:3-kcryptd
26246 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/u13:4-kcryptd
26249 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/u13:6-kcryptd
26291 root      20   0   17232   3292   2932 R   0.0   0.0   0:00.00 top

[brotech]

Hello jnko,

sorry I made a typo, it should be ipcs -m instead of -s.

For question ‘why there is problem with shared memory’ – we suspect an application is leaking shared memory.

[brotech]

About the ‘there is problem with shared memory’ I need to explain better. It all depends on how Unix is dealing with MIT-SHM shared memory. We suspect an application is leaking shared memory. The operating system is not dealing with these memory leaks by its own. The available shared memory, in the end, is all taken and other applications, like NX, can’t allocate more. Why now? Well, can be some application upgrade… The solution is simple: find out which application is leaking shared memory and fix it. It’s unlikely that the application leaking shared memory is NX, since NX is in use on millions of machines and we had not similar reports from other users, but can be, of course, that’s why we need to investigate on your machine. We are also discussing the option of checking the shared memory in use, and recovering the segments that are clearly the fruit of some application’s leak. And! We have planned to move away from MIT-SHM, and use some shared memory interface that is more modern, multiple times… But the time is never enough.

[jnko]

Thanks for explanation.

Here’s the output from ipcs -m attached

root@l ~# ipcs -m

—— Shared Memory Segments ——–
key        shmid      owner      perms      bytes      nattch     status
0x00000000 1563983872 l          777        3200       2
0x00000000 1564016641 l          777        2880000    2
0x00000000 1564049410 l          777        2048       2
…. and 4000 more lines of this. See attachment.

 

root@l ~# df -k /dev/shm
Filesystem     1K-blocks  Used Available Use% Mounted on
tmpfs            4084020 66760   4017260   2% /dev/shm

 

root@l ~# ipcs -lm

—— Shared Memory Limits ——–
max number of segments = 4096
max seg size (kbytes) = 18014398509465599
max total shared memory (kbytes) = 18014398509481980
min seg size (bytes) = 1

 

Another hint, whenever this happens, VLC (VideoLANClient) fails to playback too with error:

main error: video output creation failed
main error: failed to create video output
xcb_x11 error: shared memory allocation error: No space left on device

While the same content in mplayer works.

Now there are exactly 4096 lines output of ‘ipcs -m’ and ‘max number of segments = 4096’

I bet it would run a little bit longe if I would increase ‘kernel.shmmni = 4096’ but this would just delay the error at all. Any idea how to identify that process that leaks shm memory? Just watch the output of ‘ipcs -m’ while running the usual apps?

 

 

Attachments:

1. ipcs-m.out_.zip

[brotech]

You could find more detailed information by using ‘ipcs -mp’: columns ‘cpi’ and ‘lpid’ will provide some clues about the involved processes.

[jnko]

I’ve written a small few-liner which shows which PID has how man entries in ‘ipcs -m’

It turns out that plasmashell is using the most resources so far

l@l ~> ./shmleak
#shm:353 CMD:/bin/plasmashell (pid:576)
#shm:52 CMD:/usr/bin/x11vnc -localhost -display :0 -auth /home/l/.Xauthority -ncache_cr -noxinerama -noncache -repeat -usepw -once -nevershared (pid:4474)
#shm:2 CMD:/usr/NX/bin/nxnode.bin (pid:881)
#shm:1 CMD:/usr/bin/python3 /bin/onboard (pid:804)
#shm:1 CMD:/usr/lib/kscreenlocker_greet –graceTime 5000 –ksldfd 30 (pid:18400)

 

Thanks brotech for the time and all the kindly information and hints. I guessed that NoMachine is not the root of those problems but didn’t know how to track them down. I’ve learned much, thank you!

 

 

For anyone who wants to use my small script:

#!/bin/bash
#
# Show which Program and PID is using how much entries in kernel.shmmni
#
ownpid=$$
cntpid=ipcs -m -p | awk '{print $3}' | tail -n +4 | sort -n | uniq -c | awk '{print $1"_"$2}' | sort -rn
for p in $cntpid; do
num=echo $p | cut -d_ -f1
pid=echo $p | cut -d_ -f2
cmd=ps -o command $pid | tail -n +2
if [ ! -z “$pid” ]; then
if [ “$ownpid” -ne “$pid” ]; then
echo “#shm:$num CMD:$cmd (pid:$pid)”
fi
fi
done

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