memory management

[gusl]

In my experience, Linux is as bad as Windows. I'm routinely having to wait 5 minutes for my screen to process a simple "minimize" click.

What the hell is my computer doing that's keeping it so busy? My guess is it's swapping memory with the HD, since this only happens when I have "too many" things open.

Another solution would be to save the inactive current processes to the HD, free up the memory, and *only* load them up when requested (instead of juggling things around all the time).

Does anyone know how to turn off memory swapping? I would prefer to get an error message: "memory is full". Does anyone know which process corresponds to the screen / user input, so I can up its priority?

Why is the software of today still oblivious to the user's experience?

Comments

[bondage-and-tea.livejournal.com]

I agree about Linux's crapness. It totally thrashes my harddrive even when I'm doing nothing spectacular!

I am always surprised by that...

[dwagoner.livejournal.com]

I have a Linux box set up in my study [old machine, low memory] with a small SuSE distro and I am always amazed at the ferocity with which it is whacking the harddrive while doing nothing but waiting for me to use my KVM switch to get back to twiddling with it. If I look at the jobs running, none of them seem to justify the furious way it is chewing up the lifespan of that drive.

I am a Linux newbie though, so I assumed that I had something set incorrectly.

[krasnoludek.livejournal.com]

Windows is still oblivious to the user's experience because it only focuses on studying users who are afraid of computers or don't know how to use them. That's why most of the user interface improvements to Windows over the past few editions have all involved assisting you with hints on how to do tasks. It drives more experienced users nuts, and Windows has finally implemented a couple options to turn some of these hints off, but still far too few to make experienced users not feel insulted every time a hint pops up. At least that stupid fucking paperclip in Office can be turned off now.

Linux probably faces the opposite problem: they have such a more experienced and smaller user base, that they probably don't feel they need to invest as much time in studying user experience. They figure that computer experts don't want to be coddled. This slightly elitist "we don't need to be pandered with fancy user improvements" view prevents even useful user interface improvements from being implemented (or even worked on).

Perhaps Macs should be applauded for falling somewhere in between? Although they are beginning to follow the Windows track.

[gustavolacerda.livejournal.com]

I guess you interpreted my question as "why don't they do some usability tests?"

But what I meant was more like AI question: "why don't these systems have a model of the person behind the computer?"

While I don't want computers interfering with my decisions,

While the experienced user doesn't want the computer interfering with what he sees because he wants his actions to be predictable (we hate too much automation), decisions about memory management should be delegated to the system: they are fair game because they don't affect the structure of the "virtual world" that the user sees.

Also, I hold that "user-friendly vs. powerful" is a false dichotomy.

[jbouwens.livejournal.com]

I don't recommend this, but if you insist:

Your swap partition has a device name such as "/dev/hda2". Use this in combination with the "swapoff" and "swapon" commands to turn this partition on or off.

[gustavolacerda.livejournal.com]

why is this not recommended?

[jbouwens.livejournal.com]

No rational reason. It's just something I would be reluctant to experiment with. Swapping in itself is not a bad thing, and there are usually better ways to reduce thrashing than disabling swapping altogether (Which can lead to weird system behavior).

[gustavolacerda.livejournal.com]

there are usually better ways to reduce thrashing than disabling swapping altogether

please?


I don't have the swapon / swapoff commands in my system.

[gustavolacerda.livejournal.com]

Do you know how to use swapoff in a Fedora system?

Any other suggestions to reduce thrashing are welcome too!

[peamasii.livejournal.com]

The linux kernel is not at fault, there is some process hogging your system. Most likely it's not memory usage but some other interrupt issue or high load condition. Try these commands in a shell:

ps -ef (will tell you the processes that are running, mem used, cpu used, time it ran, etc)
top (you may need to install this separately, it has a dynamic refresh of processes)
sar (install separately, this is a sysadmin utility which logs cpu load over time)
mrtg (install separately, this creates graphs of cpu load and other system parameters over time)

Probably as far as user experience goes, MAC OS X is by far the best of all worlds.

[gustavolacerda.livejournal.com]

I've tried "ps -ef" to try to give my graphics/windowing processes high priority, but I don't know which processes they are.

I'll look into these tools. Thanks.

What I'm looking for is a tool that will show me which process is so busy.

[peamasii.livejournal.com]

"nice" changes priority (the NI column below), "ps -ef" just shows you proc info so you can see the actual processes and their parameters, and "top" shows you dynamic refreshing lists of cpu/mem/resource usage. first, get top installed if you don't have it for some reason. for example this is output from "top":

19:51:31 up 14 days, 2 min, 2 users, load average: 0.04, 0.11, 0.20
192 processes: 190 sleeping, 1 running, 1 zombie, 0 stopped
CPU states: cpu user nice system irq softirq iowait idle
total 0.0% 0.0% 1.5% 0.0% 0.0% 0.0% 98.4%
Mem: 506532k av, 502156k used, 4376k free, 0k shrd, 11820k buff
234364k active, 238888k inactive
Swap: 1012084k av, 606476k used, 405608k free 30532k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND
29142 root 17 0 1320 1320 896 R 1.7 0.2 0:00 0 top
1 root 16 0 412 384 356 S 0.0 0.0 0:08 0 init

I only copied the first two processes, out of 192. The "load average" showing values under 1 means everything is A-OK. If I wanted to track down some intermittent CPU load issue, I could log top output to a file to take 20-second interval snapshots of the system processes.

Come to think of it, what I really mistrust in Linux is that if you crash the filesystem you end up having to re-install. Fortunately it doesn't happen often. :-)

[smandal.livejournal.com]

You can tweak how actively heavily-used apps are swapped off the hard disk and into physical memory with /proc/sys/vm/swappiness. For example, I set mine "echo 60 > /proc/sys/vm/swappiness" at root when on AC power, and "echo 20 > /proc/sys/vm/swappiness" when I switch to battery power.

Oh, and buy more RAM -- it's cheaper than a Windows license.

[dusc.livejournal.com]

I routinly turn off swapping on Windows machines, and I've seen similar problems on other systems, but not for many years. It could be the you're overusing RAM, and forcing the thing to swap like mad.
Kill the swap space, and you'll probably get an error return on a process or two, which may be nothing more than a number representing an "out of memory error". The memory hog itself may cause another app to die before it kills itself, or it may back off on the memory grabbing, letting others die around it; depends on the coders.
If it's not a configuration error, and it is just a memory overuse, then having more physical memory is the best responce.

[gustavolacerda.livejournal.com]

However much memory you give me, I will leave too many things open, unless the system reminds me to clean up my shit (but as I argued in the post, that shouldn't be necessary if they saved my memory to HD instead of swapping).

[dusc.livejournal.com]

Shouldn't take too long for anyone who makes GUIs to slap togeather a little warning app, which periodically monitors free memory and opens a live report window if it falls/stays below a warning level, ironically consuming more resources. It wont use much CPU time at all if you sleep 1 full second between each check cycle.

Your suggestion for saving things to the HD is basically what swapping does. The only difference seems to be in the application being fully inactive until the user (you) reactivates it, instead of waking up to do trivial little things. Sounds like an application level edit to me.
I don't know what you're running, but does your OS allow you to manually "Pause" a process?