Multiple U4 freezes (with debug logs)
Multiple U4 freezes (with debug logs)
I've just had my U4 freeze (spinning wheel of doom on screen) two times in fairly quick succession, requiring a reboot via ssh each time. This happens probably a couple of times a month for me, but today is the first time that it has happened twice in a day. It always happens when I'm just changing channels using the up/down channel buttons. Nothing else special going on.
I have debug logs turned on, so I've attached the two from today.
I have debug logs turned on, so I've attached the two from today.
- Attachments
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- Enigma2-2021-08-29_12-32-36.log
- (194.8 KiB) Downloaded 40 times
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- Enigma2-2021-08-29_12-17-52.log
- (474.39 KiB) Downloaded 43 times
U4 500GB (beta update feed, OverlayHD)
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
-
- Wizard God
- Posts: 32714
- Joined: Tue Sep 04, 2007 13:49
- Location: Canberra; Black Mountain Tower transmitters
Re: Multiple U4 freezes (with debug logs)
What firmware version are you running? (MENU>Information>About>Revision)
Peter
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Sony BDV-9200W HT system
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Re: Multiple U4 freezes (with debug logs)
Looks like 19.3-20210826.0 beta that has not been update to the latest version.
I also notice that you are using OverlayHD. Please test for the issue after a USB reflash and without installing any additional plugins that are not already in the USB image.
I also notice that you are using OverlayHD. Please test for the issue after a USB reflash and without installing any additional plugins that are not already in the USB image.
Re: Multiple U4 freezes (with debug logs)
Yeah, I haven't yet installed today's beta update, but this issue has been going on for a year, maybe more, so it's not a recent update thing.
To be honest, I'm not going to reflash etc, etc because in general the issue happens just too rarely (other than today); I really can't "test for the issue" in any meaningful way. There's obviously a race condition somewhere in the code, and if you can't determine anything from the debug logs then there's not much to be gained by me having to go through all of that.
Note that someone else posted about a same/similar issue a few months ago (viewtopic.php?f=47&t=14707) although they posted the output from /var/log/messages, which I probably should have done but didn't think of it. Not sure if this is the same thing.
U4 500GB (beta update feed, OverlayHD)
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Re: Multiple U4 freezes (with debug logs)
gtwundke wrote: ↑Sun Aug 29, 2021 16:11this issue has been going on for a year, maybe more, so it's not a recent update thing.
To be honest, I'm not going to reflash etc, etc because in general the issue happens just too rarely (other than today); I really can't "test for the issue" in any meaningful way. There's obviously a race condition somewhere in the code, and if you can't determine anything from the debug logs then there's not much to be gained by me having to go through all of that.
Note that someone else posted about a same/similar issue a few months ago (viewtopic.php?f=47&t=14707) although they posted the output from /var/log/messages, which I probably should have done but didn't think of it. Not sure if this is the same thing.
Fair enough. If it is indeed the front panel icon deadlock, it would be nice to have a matching set of kernel and application logs. Not that this would guarantee a fix. The problem appears to be in the U4 hardware drivers and I don't really expect to see any further updates in the future. Reducing the likelihood of triggering the problem from within enigma2 is probably the best chance of addressing this, but it may just not be possible.
Re: Multiple U4 freezes (with debug logs)
Hmm, maybe something has changed that is making this more frequent, as it has happened again just now. I'm on the latest beta firmware (updated this morning).
Here's the debug log and /var/log/messages.
Here's the debug log and /var/log/messages.
- Attachments
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- var-log-messages.txt
- (67.82 KiB) Downloaded 41 times
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- Enigma2-2021-08-31_17-08-10.log
- (102.27 KiB) Downloaded 43 times
U4 500GB (beta update feed, OverlayHD)
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
-
- Wizard God
- Posts: 32714
- Joined: Tue Sep 04, 2007 13:49
- Location: Canberra; Black Mountain Tower transmitters
Re: Multiple U4 freezes (with debug logs)
There are definitely some problems:
kworker is an internal kernel process responsible for much of what the kernel does.
I'm having a bit of a problem matching up the place in the /var/log/messages file where the first of those errors happen with the timestamps in the Enigma2-*log file.
The messages file says that the system was started at about 15:30 and the firsd "task kworker blocked" message was at about 17:18 (132 min or about 7900 seconds after boot time).
The timestamp in the Enigma2-*.log file says that the enigma2 process (which runs the PVR functionality) started at about 17:08, but its latest timestamp is about 480 seconds (about 8 minutes) after boot time.
Code: Select all
Aug 31 17:18:02 beyonwizu4 user.err kernel: INFO: task kworker/0:0:4 blocked for more than 120 seconds.
I'm having a bit of a problem matching up the place in the /var/log/messages file where the first of those errors happen with the timestamps in the Enigma2-*log file.
The messages file says that the system was started at about 15:30 and the firsd "task kworker blocked" message was at about 17:18 (132 min or about 7900 seconds after boot time).
The timestamp in the Enigma2-*.log file says that the enigma2 process (which runs the PVR functionality) started at about 17:08, but its latest timestamp is about 480 seconds (about 8 minutes) after boot time.
Peter
T4 HDMI
U4, T4, T3, T2, V2 test/development machines
Sony BDV-9200W HT system
LG OLED55C9PTA 55" OLED TV
T4 HDMI
U4, T4, T3, T2, V2 test/development machines
Sony BDV-9200W HT system
LG OLED55C9PTA 55" OLED TV
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- Uber Wizard
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- Location: Perth
Re: Multiple U4 freezes (with debug logs)
The messages file timestamp starts in 1970. It gets current time at 17:08:10.
I make the last write to the debug log to be ~17:15:49.
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- Wizard God
- Posts: 32714
- Joined: Tue Sep 04, 2007 13:49
- Location: Canberra; Black Mountain Tower transmitters
Re: Multiple U4 freezes (with debug logs)
Hmm. Quite right. I don't know what I did there. I'll try to have another look at it tomorrow.
Peter
T4 HDMI
U4, T4, T3, T2, V2 test/development machines
Sony BDV-9200W HT system
LG OLED55C9PTA 55" OLED TV
T4 HDMI
U4, T4, T3, T2, V2 test/development machines
Sony BDV-9200W HT system
LG OLED55C9PTA 55" OLED TV
-
- Uber Wizard
- Posts: 6490
- Joined: Thu Mar 05, 2009 22:54
- Location: Perth
Re: Multiple U4 freezes (with debug logs)
It appears to be the same front panel icon deadlock that I've previously posted details about.
Re: Multiple U4 freezes (with debug logs)
Definitely front panel related deadlock issue. Piecing some of the clues together, it looks like there are three players involved. The recording indicator, the scrolling of a front panel message (one that is too long for the display) and an update of the front panel icons as a demux is being freed.
At a guess, the scrolling of the front panel is going to be the slowest to run and therefore increase the risk of deadlock the most. Sending shorter message strings to the front panel (to avoid scrolling) may be a feasible mitigation strategy.
At a guess, the scrolling of the front panel is going to be the slowest to run and therefore increase the risk of deadlock the most. Sending shorter message strings to the front panel (to avoid scrolling) may be a feasible mitigation strategy.
Re: Multiple U4 freezes (with debug logs)
peteru wrote: ↑Tue Aug 31, 2021 23:37Definitely front panel related deadlock issue. Piecing some of the clues together, it looks like there are three players involved. The recording indicator, the scrolling of a front panel message (one that is too long for the display) and an update of the front panel icons as a demux is being freed.
At a guess, the scrolling of the front panel is going to be the slowest to run and therefore increase the risk of deadlock the most. Sending shorter message strings to the front panel (to avoid scrolling) may be a feasible mitigation strategy.
To be perfectly honest, I'd be entirely happy if there was an option to turn off all of that information from the front panel display. I've never once looked at it for information, as it's just too small and too far away.
Maybe there's scope for multiple more nuanced options, in terms of what gets displayed, but I'm guessing that most people won't be that picky. Show it all, and risk the bug, or turn it all off (and just display the time, or whatever).
U4 500GB (beta update feed, OverlayHD)
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Re: Multiple U4 freezes (with debug logs)
gtwundke wrote: ↑Wed Sep 01, 2021 16:29To be perfectly honest, I'd be entirely happy if there was an option to turn off all of that information from the front panel display. I've never once looked at it for information, as it's just too small and too far away.
Maybe there's scope for multiple more nuanced options, in terms of what gets displayed, but I'm guessing that most people won't be that picky. Show it all, and risk the bug, or turn it all off (and just display the time, or whatever).
Note that I realise that you can turn the front display completely off (which I'm assuming would fix this issue?), but the one thing that it is actually helpful for is seeing whether the box is turned on or not, and what state it's in, so it would be nice to at least have the time or something displayed.
U4 500GB (beta update feed, OverlayHD)
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite
Synology DS918+
Pioneer SC-LX73 Receiver
Samsung PS50C7000 50" Plasma
Logitech Harmony Elite