1

2 years using linux, reasonably comfortable and confident at it now, but this is something that keeps plaguing me and I have lost so many work hours because of freezes/lockups.

My understanding of memory reporting in linux is probably incomplete, as I'm no mathematician, but when the system monitor memory graph jacks right up to full, determining the total memory being used by adding up all the processes memory usage doesn't even come close to matching. I have read in many linux discussions this is 'normal' and the graph is over-reporting memory usage (is this correct?)

For example: if we add up these memory usages

enter image description here

It's not close to what the graph is reporting: (6.3gb) enter image description here

I'm ok with the graph 'over-reporting' memory use, however as soon as that graph hits the top, the whole system locks up. I have watched it real time whilst trying to pin down the exact problem. So is it really over-reporting?

When I open the same file in the same program (blender) under windows, there is no problems. Please there is no need to explain that blender is a memory intensive program, as I know, and I watch the available memory closely while I work, but why does it work fine under windows, yet very, very, very frequently lock up the whole system needing a hard reboot under linux?

I hope someone can shed some light on this, and thankyou in advance for your time.

John October Rage
  • 11
  • 4
    Does this answer your question? Memory watchdog for hungry applications TLDR: install and enable earlyoom and check if it helps. – Artem S. Tashkinov Jan 04 '22 at 03:21
  • thankyou Artem I shall try this immediately and update this question with results. – John October Rage Jan 04 '22 at 03:24
  • Well it certainly stops the lockups, instead it kills blender when it gets to about 9gb of memory use, which means the system is using the other 7gb to just idle in the background? It feels like the graph on system monitor is not over-reporting, rather the process table is under-reporting memory use. It makes me wonder why the system monitor memory reporting exists at all if it is so inaccurate/unreliable. Thankyou for the idea though Artem :) I do hope there is a way to not have to use windows ;) – John October Rage Jan 04 '22 at 05:09
  • 1
    The normal is not this normal. The 'normal' is the one free says, including cache and buffer. – Abdullah Ibn Fulan Jan 04 '22 at 05:09
  • Hi Abdullah are you referring to a different system monitor? – John October Rage Jan 04 '22 at 05:24
  • @JohnOctoberRage, I am talking about free command. Run free -h. Graphically, see Memory in KDE Infocenter. – Abdullah Ibn Fulan Jan 04 '22 at 13:12
  • 1
    Have you taken Shared memory in account ? Your Plasma System Monitor isn't showing the column. – Abdullah Ibn Fulan Jan 04 '22 at 13:15
  • 1
    The unexplained RAM utilization could also be due to a tmpfs being mounted in RAM. Check the size of your tmpfs filesystems and see if it matches up. I ran into a similar issue and was annoyed by 50% of my RAM being used. – dcom-launch Jan 04 '22 at 14:49
  • @Abdullah thankyou for pointing this out it says 2gb is shared, I'm trying to understand why the system seems to not be allowing the memory to be used as needed. I do comprehend that the system allocates memory to optimize performance, but I'm confused, because not being able to use the memory as required does not seem very optimal to me. I would do anything to avoid using vile windows, but in this case it seems to be winning :O – John October Rage Jan 04 '22 at 15:45
  • Hi Dcom-launch thanks for that suggestion. This is probably completely wrong but here goes... the /tmp folder is empty and the info centre disk cache is reporting 7gb used. Could this be the culprit? Disk cache? Its a nice thought that the system is trying so hard to optimize everything so much but if that memory is unusable then that is, well the opposite of optimal. I probably have terminology wrong here sorry. – John October Rage Jan 04 '22 at 16:03

0 Answers0