Stuck processes

Question

Stuck processes

In the Terminal, when using the top command I can have:

Processes: 64 total, 3 running, 3 stuck, 58 sleeping... 309 threads 17:39:12
Load Avg: 0.34, 0.21, 0.13 CPU usage: 3.81% user, 3.33% sys, 92.86% idle
SharedLibs: num = 7, resident = 41M code, 2592K data, 3068K linkedit.
MemRegions: num = 8115, resident = 238M + 20M private, 313M shared.
PhysMem: 244M wired, 470M active, 1299M inactive, 2017M used, 31M free.
VM: 7177M + 373M 90075(0) pageins, 1095(0) pageouts

What are stuck processes? I have read somewhere that I can identify them with ps -Aj and the Stautus code E.

I find S, Ss, R, U, S+, R etc but no E.

Are these processes harmless? So called Zombies? Or what else?

iMac 24, Mac OS X (10.5.6)

Posted on Jun 5, 2009 8:43 AM

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Answer 1

Kappy

Level 10

362,007 points

Jun 5, 2009 9:47 AM in response to Urs Gruetzner

If you run ps -Aj in the Terminal an "E" only appears for a process that will not quit. A stuck process, I believe, is one that is not responding. If you open Activity Monitor, select All Processes from the Processes drop down menu, click on the Process Name column, then look for a process displayed in red. That would be a non-responding process.

The top output you put in your post does not display any processes, so it's impossible to know which ones are stuck. You might also check the console log using the Console application in the Utilities folder to see if there's any information there regarding processes that are malfunctioning.

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Answer 2

glsmith

Level 3

875 points

Jun 5, 2009 10:10 AM in response to Urs Gruetzner

Take a look at the man page for "ps". Under the section called "State", you'll see each flag explained.

Having zombie processes doesn't necessarily indicate things are wrong, but having lots of them probably is an indication that you have parent processes that aren't behaving nicely. One negative about having zombies is that if unchecked, they can fill up your process table. A reboot will clear them up.

You can read about zombie processes here:

http://en.wikipedia.org/wiki/Zombie_process

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Answer 3

nerowolfe

Level 6

13,090 points

Jun 5, 2009 10:03 AM in response to Urs Gruetzner

I often get "stuck" processes. They are not really stuck because the number of them changes 🙂 Sometimes 2, sometimes 3, sometimes 1 - as I watch them the number changes.

More serious is that you show many pageouts. These are not good. It usually indicates too little RAM, requiring temporary storage on the HD, which, of course, slows things down considerably.
http://www.thexlab.com/faqs/lackofram.html
I have never seen any pageouts on my computers.

Message was edited by: nerowolfe

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Answer 4

Kappy

Level 10

362,007 points

Jun 5, 2009 10:24 AM in response to nerowolfe

Nero,

The Pageouts reads 1095(0). Since the figure in parentheses is zero this indicates there are no instantaneous pageouts occurring, so his memory situation is fine. And, that's also confirmed by the amount of inactive RAM. I don't see an indication of a RAM shortage. The 1095 figure is the cumulative number of pageouts that have occurred during the system's uptime. The more critical figure is the one in parentheses. If that is positive and increasing, then there's definitely not enough RAM installed for the number of concurrent applications running.

The snapshot provided does not suggest a RAM shortage. Of course adding more RAM can't hurt.

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