High RAM Usage RT-AC86U

[Makaveli]

It is normal unused Ram is wasted ram.

Stop worrying about it.

Linux knows how to handle ram management.

 

[Val D.]

Linux knows how to handle ram management.

In theory... in real life something stops working sooner or later. I did some torture tests recently with bad results:
https://www.snbforums.com/threads/s...-cat-6-cable-with-rt-ac87u.59444/#post-518441

RAM at 95% means something has to get out in order for something else to get in. Definitely not the best situation.

 

[cmkelley]

In theory... in real life something stops working sooner or later. I did some torture tests recently with bad results:
https://www.snbforums.com/threads/s...-cat-6-cable-with-rt-ac87u.59444/#post-518441

RAM at 95% means something has to get out in order for something else to get in. Definitely not the best situation.

Not necessarily. In any modern operating system, "free" and "used" are not the only states memory can be in. In fact, given the limited scope of what your router does, it could easily mean the thing you want to get "in" is already there from a previous instance and just has to be changed back from "available" to "in use" (this is a large over-simplification, I don't pretend to understand the details). It's slightly more likely that whatever needs to get "in" just overwrites "available" memory (that is already marked as "used") and that memory area is marked then marked "in use" without any change in "used" memory. The Linux kernel (again, as with any modern operating system) is very stingy about actually marking memory "free" even when it's not longer "in use".

Running certain scripts (I think Diversion is one of them) you should have a swap file on a USB stick because it will likely need it during certain operations. I run enough scripts and daemons and such that currently, after 6 days uptime, I have 95% memory "used" and 105 mb (out of 512 mb) swap file "used" on my AC86U. This is perfectly normal.

Free memory is wasted memory.

 

[Val D.]

you should have a swap file on a USB stick

This by itself sounds ridiculous. It’s equal to force the extra 100 passengers to walk behind the bus. In my tests the swap file was on a SSD drive connected to USB3 port using USB3 mode... >500Mb swap in use and the “modern OS” was still choked by the lack of RAM. Actually, RT-AC86U is killing services only with TrendMicro components enabled due to memory leaks. Just enable everything offered by TrendMicro and wait. First thing to stop working is usually the Traffic Analyzer Statistic. Bad software is also a wasted RAM.

This router needs 1GB RAM as in RT-AX88U.

 

[sfx2000]

ZRAM is cool... but maybe folks worry too much about memory...

root@cafeole:~# dmesg | grep zram
[   53.546889] zram: Added device: zram0
[   61.121939] zram0: detected capacity change from 0 to 16777216
[   61.145769] Adding 16380k swap on /dev/zram0.  Priority:-2 extents:1 across:16380k SS
root@ceafeole:~# free
              total        used        free      shared  buff/cache   available
Mem:          58668       23636       18972         624       16060       15520
Swap:         16380           0       16380
root@ccafeole:~# df -h
Filesystem                Size      Used Available Use% Mounted on
/dev/root                 4.3M      4.3M         0 100% /rom
tmpfs                    28.6M    624.0K     28.0M   2% /tmp
/dev/mtdblock5            9.8M    428.0K      9.3M   4% /overlay
overlayfs:/overlay        9.8M    428.0K      9.3M   4% /
tmpfs                   512.0K         0    512.0K   0% /dev

 

[sfx2000]

ZRAM is cool... but maybe folks worry too much about memory...

Had to change hostnames because of cloudflare... anyways - folks worry about RAM - consider living in a 64/16 environment

Linux cafeole 4.19.76 #0 Fri Oct 4 18:42:26 2019 mips GNU/Linux

 

[cmkelley]

This by itself sounds ridiculous. It’s equal to force the extra 100 passengers to walk behind the bus. In my tests the swap file was on a SSD drive connected to USB3 port using USB3 mode... >500Mb swap in use and the “modern OS” was still choked by the lack of RAM. Actually, RT-AC86U is killing services only with TrendMicro components enabled due to memory leaks. Just enable everything offered by TrendMicro and wait. First thing to stop working is usually the Traffic Analyzer Statistic. Bad software is also a wasted RAM.

This router needs 1GB RAM as in RT-AX88U.

No amount of memory will fix a memory leak. All putting a GB of ram in it will do is delay the inevitable, and then you'd want 2GB. You cannot fix bad software with more memory.

If the router needed a swap file running stock firmware with no additional scripts, then yes, it would be more than fair to say it needed more memory. But I can't blame ASUS for the fact that I need a swap file when I'm running some fairly heavy scripts (Diversion, Skynet, etc.) and daemons that aren't part of the base firmware (pixelserv, syslog-ng, etc.). Why should ASUS put more memory in their routers than what is required to run the firmware they supply?

ASUS not pressuring TrendMicro to fix their crap is another story, they definitely should be doing that.

 

[RMerlin]

ASUS not pressuring TrendMicro to fix their crap is another story, they definitely should be doing that.

I know that 384_81xxx contains bug fixes related to Trend Micro, so it's possible that any memory leak in there (if there really is one) might be fixed already.

I know that one memory leak in Asus's own code was recently fixed in 384_81116, more specifically in the httpd server.

 

[Val D.]

I'm running some fairly heavy scripts

Not really. None of those scripts uses much of the CPU time (on RT-AC86U at least), nor big amounts of RAM. The swap file is a "plan B" solution for routers with 256MB RAM like RT-AC68U. It just makes things possible on those routers, but it is far from optimal. On RT-AC86U swap file is not used even if most of the popular scripts are installed and running. I had like 6-7 scripts running for a week (including Diversion and Skynet) and the swap usage was always 0MB. If the swap is really needed and is in active use, you'll see/feel it right away. Even the WebUI slows down to unusable state.

and then you'd want 2GB

That would be great. Unfortunately, ASUS will give us only the minimum required. Business, every dollar counts, you know. No memory management will fix lack of RAM. More RAM is always better, even if part of it is not in use at the moment. This "better memory management" myth is around for decades, but in real life all electronics from computers through mobile devices to printers, if you like, slow down significantly or just start to kill processes in order to deal with low RAM conditions. A memory chip for $5 works much better than any kind of memory management. Windows 10 requires 2GB RAM only. How much RAM you have installed in your computer, for example, and why?

 

[Val D.]

Why should ASUS put more memory in their routers than what is required to run the firmware they supply?

Because if you enable whatever is offered in their firmware the router's RAM gets full and processes start getting kicked out. Do an experiment and enable all TrendMicro services. The RAM usage starts creeping up to the point only 25MB are still available. You'll have to reboot the router weekly in order to keep it going, otherwise something just stops working, including WebUI. Yes, part of the problem is software related, but this software was provided by ASUS. Two years after the router's release ASUS is struggling to fix the software. Good we have RMerlin around to make things better.

 

[gattaca]

It is normal unused Ram is wasted ram.
Stop worrying about it. Linux knows how to handle ram management.

Yes and Maybe. From my extensive performance and tuning knowledge of OSes, Linux thinks it knows how to manage pRAM and really what it does is create a huge "file cache" to supplement the slowest thing on the system. YMMV. There are cases where this is not a very good idea. BTW, did you guys see ABC's findings that the current Linux kernel full of previously unknown race conditions and that's in their initial scans...

https://www.phoronix.com/scan.php?page=news_item&px=Google-KCSAN-Sanitizer

Peace.

 

[Val D.]

Linux thinks it knows

Well, how many of you purchased an Android phone thinking it is the best phone you ever had in your hands? Lots of RAM, lots of CPU power, lots of everything... great! And one day you just want to smash the phone off the ground because the apps got bigger and more demanding and now the phone lags like crazy due to "excellent memory management". The fact is the amount of RAM installed is like future proofing. Manufacturers who release a device with minimum required RAM won't go too far. This is part of the business though. No manufacturer wants you to use a device for too long. They have to sell new products and keep the business going after all.

 

[Makaveli]

Well, how many of you purchased an Android phone thinking it is the best phone you ever had in your hands? Lots of RAM, lots of CPU power, lots of everything... great! And one day you just want to smash the phone off the ground because the apps got bigger and more demanding and now the phone lags like crazy due to "excellent memory management". The fact is the amount of RAM installed is like future proofing. Manufacturers who release a device with minimum required RAM won't go too far. This is part of the business though. No manufacturer wants you to use a device for too long. They have to sell new products and keep the business going after all.

So now were comparing Andriod Ram management vs linux?

Kinda apples vs oranges no?

 

[cmkelley]

Because if you enable whatever is offered in their firmware the router's RAM gets full and processes start getting kicked out. Do an experiment and enable all TrendMicro services. The RAM usage starts creeping up to the point only 25MB are still available. You'll have to reboot the router weekly in order to keep it going, otherwise something just stops working, including WebUI. Yes, part of the problem is software related, but this software was provided by ASUS. Two years after the router's release ASUS is struggling to fix the software. Good we have RMerlin around to make things better.

You missed the point entirely. If there's a memory leak, if they had put 16GB of ram in the thing, it would be once a month you'd have to reboot instead of weekly. If there are leaks in TrendMicro's code, RMerlin can't fix them, those sections are closed source.

 

[cmkelley]

Manufacturers who release a device with minimum required RAM won't go too far.

History says otherwise.

 

[Val D.]

So now were comparing Andriod Ram management vs linux?

Yes, Android is a Linux based OS, also claiming "excellent memory management".

You missed the point entirely. If there's a memory leak...

What I miss the most is proper engineering. You buy something and it works as advertised/expected.

 

[sfx2000]

What I miss the most is proper engineering. You buy something and it works as advertised/expected.

With consumer gear - you rarely get this...

With AsusWRT-RMerlin - you have a chance - but there are closed source items that just can't be solved...

 

[Butterfly Bones]

So now were comparing Andriod Ram management vs linux?

Kinda apples vs oranges no?

I know you got one reply that Android kernels are Linux based, I just want to provide a source with more info.
https://source.android.com/devices/architecture/kernel

Having been a long time Android geek, there is a tool called Android Debug Bridge that allows access to the Android (Linux) system, if one looks closely, the Android CLI commands are Linux commands.
https://developer.android.com/studio/command-line/adb.html

/OT

 

[TNCS]

With consumer gear - you rarely get this...

With AsusWRT-RMerlin - you have a chance - but there are closed source items that just can't be solved...

Yeah, when you work long enough in the industry, you'll not say that.... Ever seen a US$ 1mil router fail to deliver what it says? Ever seen a US$ 300k router went nuts due to continuous ping hog to much processor cycle?

 

[sfx2000]

Yeah, when you work long enough in the industry, you'll not say that.... Ever seen a US$ 1mil router fail to deliver what it says? Ever seen a US$ 300k router went nuts due to continuous ping hog to much processor cycle?

Oh, I have - I think the key difference with that $1M router is there is also a help desk and a service level agreement in place to get hot-fixes in a fair fast matter...

(as many long time members know, I've spent a fair amount of time at one of the big four wireless carriers here in the US - so yes, I've seen those $1M routers go nuts from time to time)