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I'll have like 2 applications open and be at 9GB of RAM. (lemmy.today)
submitted 3 days ago* (last edited 1 day ago) by rounding_error@lemmy.today to c/linux@lemmy.world
45 comments fedilink hide all child comments
 

edit for this wondering, the reason is:

Also something called GTT slab exists?

original post: This is bullshit. I wanted to play Terraria last night but I looked at my RAM usage and it was sitting uncomfortably high at 13 GB (of my 15). So, I close Terraria, and it drops about 2 GB. I close Firefox, Thunderbird, and Zed, and that drops about 2.5 GB. Then I close basically everything and it's still super high! Each time this happens, I have to restart my computer in order to get the RAM usage lower.

Whenever I look this up it's usually two camps:

  • KDE is just bloated.
  • Unused RAM is wasted RAM.

To address both of these:

I disabled a few things in KDE like file indexing (which was my home directory). Cool, so that saved like 100 MB. KDE is supposed to idle at around 3GB anyways, so what now?

The "unused RAM" belief is like a folktale at this point. It's not true anymore, and buffered/cache memory is shown separately. Plus, I can drop those caches whenever I want... Which I did. File inode cache only really became a problem for me when I was doing Minecraft Datapack development and I was creating hundreds of files on a regular basis as part of hot reload. Then I'd have to drop the entire cache because it wasn't being free'd...

However, the RAM I'm complaining about is actually not that, because it steps on my available RAM meter. Having a game freeze up because I was out of memory is a pain in the ass.

I even tried installing Zram, which only made matters worse since the active memory allocations seemed to be robbing the CPU of time it would be running game code, just so it could compress file pages. (My system has also just had major lag problems with swap, in general, during high memory pressure, which I should probably report as a bug). My swappiness was probably way too high, but regardless I didn't see major improvements from that and it only seemed like a bandaid to the real problem. Also, why should I need to use swap when I have 16 GB of RAM and only a few programs open at a time?

This whole thing is pretty annoying. Whenever I have like 11 hours of uptime my memory is unusually high. I also can't seem to track it down to any particular application...

System: OpenSUSE Tumbleweed

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[–] fraksken@infosec.pub 45 points 3 days ago (2 children)

Memory free ≠ memory available.

[–] daychilde@lemmy.world 10 points 3 days ago (1 children)

Memory free

Memory free? I'll take a half dozen!

[–] hansolo@lemmy.today 5 points 3 days ago (1 children)

I'll take the other half!

[–] JigglySackles@lemmy.world 4 points 3 days ago (1 children)

Dammit, I'm too late.

[–] daychilde@lemmy.world 3 points 3 days ago (1 children)

You get the third half :)

[–] JigglySackles@lemmy.world 3 points 2 days ago

Fuck yeah!

[–] Treczoks@lemmy.world 12 points 3 days ago

Learn to read RAM usage data. Even after short use, a lot of RAM is in use instead of just free, and that is by design. Look at what it is used for. Because since about the moment Linux got block devices, unused RAM is used as disk buffers.

[–] passenger@sopuli.xyz 29 points 3 days ago* (last edited 3 days ago) (1 children)

Read this

https://www.linuxatemyram.com/

Edit: seems im in unused ram is wasted ram camp

[–] scrubbles@poptalk.scrubbles.tech 12 points 3 days ago

I am too. Why not use your ram, you paid for it. Else you're writing to slow files and and caching things. I'd gladly have everything I need in ram if it fits.

What I'm more concerned about is applications releasing ram when I need it back. If I start a game will the browser give back the ram? That's my only concern though

[–] ninekeysdown@lemmy.world 12 points 3 days ago

Just from that screenshot, I don’t see anything wrong. Your load is fine, you’re not swapping, and you have plenty of stuff cached with plenty of room to spare.

Linux will try to cache as much as possible into memory; it doesn’t mean that it’s “using” it. So it seems like you’re conflating memory used with memory availability.

If you start spilling into swap, then you’re getting a little high on your usage. For most people, the default settings for everything are fine; it’s also possible to over-optimize your system into worse performance.

[–] bjoern_tantau@swg-empire.de 22 points 3 days ago (1 children)

I'm in the unused RAM is wasted RAM camp. Unless I run into problems I don't care about memory usage. So in your case I would've kept playing unless I got constant stutters.

And I think KDE is surprisingly light. Especially compared to older versions.

[–] mantricx@lemmy.world 4 points 3 days ago

I mean I think KDE is the heaviest it’s ever been, it just started out heavier than its competitors but grew slower. So it’s light enough now that we’re not using pentium 4 with 1GB RAM.

[–] WereCat@lemmy.world 9 points 3 days ago* (last edited 3 days ago)

If unused RAM is wasted RAM then:

1.) Windows must be using more RAM to be slower a lot faster

2.) Your name is Sam Altman

[–] anamethatisnt@sopuli.xyz 14 points 3 days ago (1 children)

What does the following commands show?

df -h -t tmpfs  

free -h
[–] anamethatisnt@sopuli.xyz 1 points 3 days ago

Followup on this, if free -h show a lot of buff/cache but df -h -t tmpfs shows little usage then ti's time to look into btrfs.
You can configure snapper to use less snapshots which makes the RAM usage to handle the different snapshots lower.

[–] castironfan@lemmy.world 11 points 3 days ago

Use something like ps to list out what is using the RAM

You mention you closed Firefox and it didn’t change but you did not say how you actually measured it.

Start the system up fresh and run this command.

ps faux --sort=-%mem

Or

ps faux --sort=-rss

That will help you track down what is actually using it.

Note: browsers will soak up a ton of memory on modern systems as almost all of them sandbox tabs at this point. If you open a ton of tabs, that will be half your problem.

[–] frongt@lemmy.zip 11 points 3 days ago (1 children)

Like half the lines in that screenshot say Firefox, so I'm gonna guess it's mostly that

[–] rounding_error@lemmy.today 3 points 3 days ago

Yeah I thought so too. I saved about 1 GB after I took this screenshot by closing Firefox.

[–] chillxjr@lemmy.world 10 points 3 days ago* (last edited 3 days ago)

my debian KDE processes all together idle at around 2.5 gb, you must have a crapload of autostart background processes?

when I have youtube in firefox open, that takes up 4 gigs by itself

[–] LodeMike@lemmy.today 7 points 3 days ago

If you have a trillion tabs open it's a trillion applications, not one.

[–] HouseWolf@pawb.social 5 points 3 days ago* (last edited 3 days ago) (1 children)

You apparently can limit programs memory cap using cgroups. I haven't tried it however.

Wouldn't be the first....or 5th time I've seen Minecraft max out ram.

Me and some friends managed to crash a guys 64Gig server rack because the modpack my friend made had a bad memory leak.

[–] frongt@lemmy.zip 0 points 3 days ago

Meh. My desktop has 64gb and I broke it this morning by loading too much stuff into RAM.

[–] Die4Ever@retrolemmy.com 6 points 3 days ago* (last edited 3 days ago) (2 children)

don't use Zram, use Zswap

[–] rounding_error@lemmy.today 1 points 3 days ago

I agree, it makes much more sense

[–] lemmyng@piefed.ca 5 points 3 days ago (1 children)

buffered/cached memory shows separately

Some of it does. Let's try an experiment: does the reported amount of used memory drop if you run the following command?

sudo sh -c 'echo 3 >  /proc/sys/vm/drop_caches'

(obligatory don't blindly trust commands from strangers, type them out instead of copy/pasting, yaddayadda)

[–] rounding_error@lemmy.today 3 points 3 days ago

I think my buffer/cache fell 8GB and my available rose 0.8gb

[–] RickyRigatoni@piefed.zip 4 points 3 days ago (2 children)

"Unused ram is wasted ram" is the worst argument I ever heard because that ram is so I can run MORE THAN ONE PROGRAM instead of some SHITASS WEB BROWSER taking all of it.

If I wanted to go back to the days before multitasking OSes when all ram was taken up by one program cuz you could only run one I'd install FreeDOS. Sick of this shit.

[–] castironfan@lemmy.world 26 points 3 days ago (1 children)

That saying is because “unused RAM” is RAM that is not being used for buffers or cache.

That RAM is quickly freed for applications when it’s requested.

[–] morto@piefed.social 3 points 3 days ago

People keep saying that, but my experience with low end devices says the opposite. The less ram things take, the better. Programs will gladly fill the "unused ram", but won't give back as easily, and when we need to open something else, the oom killer isn't fast enough, and the system freezes with the disk led flashing like crazy, so we have to restart the system and lose recent activity. Unused ram is wasted ram my ass. It's easy to say that when you have the ram to spare, but without a bit of free unclaimed space, the system goes to shit very often

[–] mhzawadi@lemmy.horwood.cloud 4 points 3 days ago

I would kill all Firefox processes and see if it's a memory leak, also free -mh will show you what's in use. Most nix systems will have a load of memory in caches

[–] Zen_Shinobi@lemmy.world 3 points 3 days ago

Specs?

Terraria is hardly resource friendly. What were you doing on FF, livestreaming?

Installing zram seems to me you have low end specs. You need a lightweight DE

[–] possiblylinux127@lemmy.zip 2 points 3 days ago

How many Firefox tabs do you have open? Close Firefox and then look at ram usage

[–] daggermoon@piefed.world 3 points 3 days ago (1 children)

Try using ZFS. My RAM is often ~53 GB idle.

[–] 2ndDegreeOWO@lemmy.world 6 points 3 days ago* (last edited 3 days ago) (1 children)

That's just because ZFS's disc cache shows up as application-used memory, instead of disc cache memory. (Disc cache memory is often reported in system monitor tools as 'free' memory, because it can be freed up as soon as you need it. ZFS's disc cache works the same way, but it's not reported separately to the OS, so that makes it look like ZFS is using a shitload of RAM.) If it bothers you, you can set a maximum amount of RAM for ZFS to use, and that will clear it up. It will mean that your performance is slightly worse, though, because ZFS won't be able to use disc caching optimally.

[–] daggermoon@piefed.world 2 points 3 days ago

Oh, it doesn't bother me. Unused RAM is wasted RAM after all. LMAO.

[–] BooBees@fedinsfw.app 3 points 3 days ago

It’s called ram spreading, it’s out of control

[–] MangoPenguin@lemmy.blahaj.zone 2 points 3 days ago

What processes were using all the ram? I'm curious if there was one huge one or if nothing seemed to be the culprit specifically.

[–] UnfortunateShort@lemmy.world 2 points 3 days ago (1 children)

You should use zwap with swappiness 100 if you want zram + swap. You can also enable and configure systemd-oomd (out of memory demon) if you actually run out of memory at times - it goes about things smarter than the kernel (for example killing processes that wait on memory all the time).

[–] Die4Ever@retrolemmy.com 1 points 3 days ago* (last edited 3 days ago)

yea, absolutely DO NOT combine Zram with regular swap, in fact don't combine any different types of swap, they don't mix

[–] Sanctus@anarchist.nexus 1 points 3 days ago

Firefox memory leak?

[–] underscores@lemmy.zip -3 points 3 days ago

KDE is bloated and buggy af. it's the first DE I used as a beginner and the bugs were just too much for me