[Klonoar]

This is getting really, really old.

Modern RAM doesn't work the way people who complain about Slack/et al think it does. The operating system will cull it from other places when it needs it; even a native Cocoa app will not dump memory you're done with until the system decides it needs it for something else, because on the off-chance your app ends up needing it again, it's already allocated. "purge" exists for a reason.

It's like when you pull up a StackOverflow answer for "how can I judge how much memory usage my process has?", and the top voted answer is some bash script to determine peak ps, when every other answer tries to explain that that's only one measure of memory and isn't even totally accurate.

Furthermore, that nice feature of most modern apps where you're scrolling up rapidly and an image is nice and ready to present? Images are big, especially when we all use retina displays. They take up memory. There was a blog post that went on HN a few months ago but didn't seem to make the front page, wherein the author determined that forcing Electron to dump image cache junk lowers the memory usage substantially.

Could Electron & co do better? For sure. Loading an entire browser for a UI does kind of suck. But stop acting like all the stuff that the browser does for you _for free_ is or should be zero-cost.

End rant, I guess.

[nottorp]

If the memory consumption of a process grows from 200 M (which is about what the chat apps use when freshly started) to 2 Gb, something is rotten by any metric. The system was responding slowly when I made that screenshot because it started using swap. Which got instafreed the moment i restarted the memory hogs.

If i don't restart the machine for a year, is the pretty chat app going to keep in ram, uncompressed, all the cat pictures that people posted in the last 12 months then? Do you think that's sane?

[mbell]

> If the memory consumption of a process grows from 200 M (which is about what the chat apps use when freshly started) to 2 Gb, something is rotten by any metric.

That is just not how memory works anymore, at least not how the OS reports it to you.

> The system was responding slowly when I made that screenshot because it started using swap.

How did you determine this? If you're looking at swap usage in activity monitor, this is also not an accurate metric. I'm sitting here with 14GB used, 18GB free and 2GB of swap usage. Using swap does _not_ mean you are out of ram, it just doesn't work like that.

Is the memory pressure graph in activity monitor yellow or red? If not, which is likely the case, you don't have memory issues. You don't need more memory and it doesn't matter how much memory your applications are using.

[smichel17]

I don't know the details of "how memory works anymore", but I do know that on my Fedora 27 laptop, everything stays nice and snappy, with under 200mb swap used, as reported by the system monitor...

...until I hit 8 gb of ram (the amount installed on my machine). The second that happens, the entire OS grinds to a halt. It starts with 5-10 seconds to change focus, and can go as high as 5 minutes if I don't do something about it. My best option for dealing with it is usually opening a new console (Ctrl-Alt-F3) and killing Android studio or the gradle daemon (the most common culprits). If I'm able and patient enough to open system monitor at this point, I can see that my swap usage has increased dramatically.

Again, I can't speak to "how memory works", but I am absolutely the expert on how my computer performs, as described above.

[opan]

I've had similar experiences. Often Firefox is what's eating all the RAM, and I'm viewing it with htop. I've had cases where the freeze is indefinite and I had to hold in the power button. Couldn't change to another TTY or even ssh into the machine. When people say SWAP isn't needed, I just get mad. I've delayed these halts a bit by having some SWAP available. If I ever get slowed mouse movement, I panic and quickly check RAM usage and determine what has to be killed or restarted. I don't really understand why people pretend this doesn't happen and that unused RAM is always wasted RAM.

[mbell]

> ...until I hit 8 gb of ram (the amount installed on my machine).

I'm assuming you mean 8GB of ram 'used', by some metric of 'used'. What tends to confuse the hell out of people is what 'used' means. It varies by how it's measured, what OS you are using and how that OS is configured. I haven't a clue how Fedora 27 is configured nor how you are determining 'used' RAM, so my comment may well not apply to your use case.

[_Tev]

I have exactly the same experience with Fedora.

And frankly, it seems to me like the issue is the OS being unoptimized or apps being leaky on it, because my Windows 7 machine with worse specs almost never has such issues, under any kind of similar load (and exactly the same apps).

[nottorp]

Quit it. It was 32 Gb used (i.e. all of it, maybe 1-2 G left for cache) plus 5-6 G of swap.

I don't know how your OS X works, but mine tends to not go into swap before running out of ram. It does not come out of swap when ram is freed indeed, but when you freshly boot it it will stay at swap used: 0 bytes until someone posts too many cat pictures in Slack or Discord.

Or until i forget how many VMs I opened, but that's work and actually useful.

Edit: I can't reply to your reply because HN doesn't like so many indents. I also don't want to continue a flame war about observed behaviour vs the theory of shared libraries and memory mapped files etc so I'll stop here.

[mbell]

What was the state of memory pressure? It's really the only thing that matters.

[jdietrich]

RAM is fast, disk is slow, network is really slow. Your operating system optimises for performance. Minimising RAM usage is bad for performance, because empty RAM is wasted RAM.

If your RAM is full, there is a probability that something will need to be read from disk. If your RAM is empty, there is a certainty that something will need to be read from disk or from the network. A probability of a slow operation is preferable to the certainty of a slow operation. Something in RAM is preferable to nothing in RAM.

The pretty chat app will not keep all of your cat pictures in RAM indefinitely, because the OS won't let it. If something else needs that RAM, then the cat pictures will be paged to disk. The OS is incredibly good at figuring out what belongs in RAM and what belongs on disk at any given moment.

[lev99]

> RAM is fast, disk is slow, network is really slow.

(all speeds are read time) RAM speed: 35 GB/s Disk speed: 3.2 GB/s Network speed: 0.87 GB/s

While you aren't wrong, I have no problem loading cat pictures at network speed instead of ram speed.

I think the real issue here is network consumption is expensive. It's better if you store all your cat pictures for as long as possible. People would complain in discord generated gigabits of temporary disk files, but RAM usage can always be freed if the OS demands it.

[Dylan16807]

Paging to disk makes it act much slower than simply releasing the memory when that cat has been off the screen for a moment. It is not a good solution.

[michaelmrose]

It's really just kind of OK at doing that and machines running lots of apps like that tend to perform badly.

You probably run a machine with above average ram and ship apps with below average performance for lack of this understanding.

[nalllar]

The 2GB in his screenshot means that 2GB has been malloc'd and used. RAM reported as in use by an application is not being used by the OS to cache things.

RAM that's reported as "free" by OS X's activity monitor/windows' task manager is used for disk caching.

RAM reported as in use by an application is in use by that application. It could be using some sort of internal cache, but it does not give that memory up to other apps under memory pressure except by the OS swapping it out which gets very slow.

[michaelmrose]

If I understand correctly this is true for the memory allocated by the os to cache files which makes intuitive sense as a file can just be read from disk if needed.

Its not clear to me how it would apply to other memory how does the os communicate to Firefox that it needs to clear out some memory for Chrome save by moving less used pages to swap with the probable high cost, of moving it back later. Further while some intelligence may be exercised insofar as which pages to swap it won't be made with the benefit of the app deciding which chunks of data to keep closer at hand.

Modern memory works the same way it always has and the best performance has always been maintained by staying within the boundaries of available ram and not needing to swap much.

When most computers have no more than 8gb of ram and consumer machines are likely to have 4 its kind of silly for a chat app to use 1-2 sillier yet to claim that the os will fix the matter.

[__sb__]

Were you thinking of this post? http://seenaburns.com/debugging-electron-memory-usage/ Curious if other people have more on it

[Klonoar]

Ah, missed the responses on this thread due to some work stuff - this looks like it, yeah! Thanks for digging it up. :)

[krispbyte]

https://www.linuxatemyram.com/

[Dylan16807]

OS cache actually gets released when there's memory pressure, which is very different from a program eating memory.