[mythtv-users] MythFrontend out of memory problem

[Kenneth Emerson]

On Sun, Apr 10, 2022 at 10:23 PM Stephen Worthington <
stephen_agent at jsw.gen.nz> wrote:

> On Sun, 10 Apr 2022 17:03:35 -0500, you wrote:
>
> >Looking for a little help from the group:
> >I'm running v31 fixes on Xubuntu v20.04 and have recently and only
> >occasionally have the kernel kill mythfrontend.re for the reason of "Out
> of
> >memory".  It has happened 3 times in the last 4 weeks and a total of 6
> >times since 2020.  It's not a show-stopper, as it does recover after about
> >5-10 minutes (I assume that's the amount of time it's using chewing up all
> >the RAM).   There isn't anything of interest in the mythfrontend.log file.
> >Just normal stuff while watching a recording.  This is a snippet from
> >kern.log specifically about mythfrontend:
> >
> >Apr  9 22:00:03 MythTV kernel: [703811.529409] [  pid  ]   uid  tgid
> >total_vm      rss pgtables_bytes swapents oom_score_adj name
> >Apr  9 22:00:03 MythTV kernel: [703811.529507] [   3635]  1000  3635
> > 97165     1257   204800      987             0 xfce4-terminal
> >Apr  9 22:00:03 MythTV kernel: [703811.529508] [   3640]  1000  3640
> >2751      196    61440      248             0 bash
> >Apr  9 22:00:03 MythTV kernel: [703811.529510] [   3753]  1000  3753
> > 652        1    45056       30             0 mythfrontend
> >Apr  9 22:00:03 MythTV kernel: [703811.529511] [   3762]  1000  3762
> > 3609880  1093884 12263424   307492             0 mythfrontend.re
> >Apr  9 22:00:03 MythTV kernel: [703811.529512] [   5513]   107  5513
> >2648       37    53248        5             0 uuidd
> >Apr  9 22:00:03 MythTV kernel: [703811.529513] [   8712]   127  8712
> > 652        0    40960       23             0 sh
> >Apr  9 22:00:03 MythTV kernel: [703811.529514] [   8713]   127  8713
> >768613   462526  4624384    46665             0 mythcommflag
> >
> >Has anyone else seen this anomaly?
> >
> >Regards,
> >
> >Ken Emerson
>
> There have been some memory leak problems with mythfrontend in the
> past, but I have not seen any in v31 or v32.  It is possible that you
> have just accumulated too many recordings now.  Mythfrontend is quite
> memory hungry - it keeps the full recording list in RAM.  So, how much
> RAM does the system have?  How much swap space is allocated?  How much
> swap space is mythfrontend.real using?  How many recordings are there?
>
> In general, these days I would recommend using at least 8 Gibytes of
> RAM for systems where there are lots of recordings.
>
> To find out what is using swap space, I use this script:
>
> https://gist.github.com/samqiu/5954487
>
> The pmap command will show the RAM usage of a process, but its output
> is not easy to interpret.  You can get all the available information
> about a process from its /proc entry (under its PID number).  Pmap
> just copies information from some of those entries.
> _______________________________________________
> Stephen:



The system RAM is 8Gb.  There is a 2Gb swap space.  There are about 3,000
recordings.  Here is the output from swap.sh:


ken at mythtv:~$ ./swap.sh


..............................

Overall swap used: 798096 kB


========================================

kB      pid     name


========================================

404072  1408    mythfrontend.re

77376   1365    xfdesktop

42080   1277    xfwm4

38504   1377    applet.py

37120   1509    blueman-tray

34504   1426    blueman-applet

15624   1131    xfce4-session

14224   1310    panel-1-whisker

12480   1321    panel-10-pulsea

12224   1317    panel-8-statusn

11536   1314    panel-6-notific

10552   1401    update-notifier

10216   1411    nm-applet

9408    1360    Thunar

9336    1282    xfsettingsd

8608    1313    panel-5-systray

8576    1318    panel-9-power-m

8528    1385    xfce4-power-man

8240    1315    panel-7-indicat

5840    1283    xfce4-panel

3280    12076   bash

3272    1382    xiccd

3032    3791    bash

2688    1123    systemd

2640    1442    polkit-gnome-au

1920    1130    pulseaudio

1224    1437    agent

504     1145    dbus-daemon

248     3784    tmux: server

240     1368    mythfrontend


ken at mythtv:~$ free -m


                    total        used        free      shared  buff/cache
available
Mem:           7934        2964         202           7        4768
 4668

If it's meaningful the CPU is an Intel i5-2500K 3.3GHz

Perhaps I am hitting some limit on number of recordings, but I don't ever
remember there being a (soft?) limit.
The system is a bit old, but I would hope it's powerful enough.  I only use
it as a media center with only MythTv as the main application.

Regards,

Ken Emerson
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