Visit The New, Modern Unix Linux Community

AIX_timeout_thread using lot of cpu time

Thread Tools Search this Thread
Operating Systems AIX AIX_timeout_thread using lot of cpu time
# 1  
AIX_timeout_thread using lot of cpu time


i am seeing some strange things on a lpar which we have at this moment.
With nmon i see a process aix_timeout_thread which is using lots of cpu (70-80%, all cpu which is "free" is used). This is a kernel process (for as far i can find out) but i am wondering what is causing this to happen and what this process is used for. We have a second partition (setup as a load balanced environment) with the same setup, but no problems with aix_timeout_thread can be seen on that one.
Partition is running aix 5.3, edge and has been moved to P770 (from P595) half a year ago.

In the morning we are going to stop and start the application to see if the process will still be active.

Anyone has an idea or have seen a similar problem?


# 2  
Any process/lwp/concurrent thread can waste CPU cycles if the author does not bother/cannot afford to sleep(). Non-concurrent threads can just yield() to each other in rotation when all are waiting for some flag or other. You can peek at the system calls it is making using truss.
# 3  
Thank you for the reply DGPickett but truss doesn't work for this process. I think that truss is not possible for this specific kernel process. I receive the message:

truss: 0915-023 Cannot control process #458894

Last edited by aixvinnie; 08-21-2013 at 10:05 AM..
# 4  
Perhaps it's more of a symptom than a cause. It may be involved in controlling user threads.
# 5  
This morning we stopped and started the application Edge..... The process aix_timeout_thread was also stopped and started during the stop and start of the application. Now the cpu utilization is back to normal so it looks like it was an internal application problem, not related to AIX.
Thanks to all,

This User Gave Thanks to aixvinnie For This Post:
# 6  
Are you using truss as root or the process owner? I have been denied calls but not so much processes ever I recall. Sometimes I had to truss earlier, like:
(sleep 2 ; exec app app_args)& truss . . . -p $!

This starts the truss during sleep 2 and shows the entire app startup,

I recall once a developer added some check to the idle loop of the X windows, to minimize A if child B was minimized and vice versa. It turned the app into a 100% cpu pig, rechecking constantly. I added a 'poll(0,0,50)' and it was fine, gave back the CPU (50 milliseconds is a blink of the eye). What do your threads do when idle?

Last edited by DGPickett; 08-23-2013 at 03:23 PM..

Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #710
Difficulty: Easy
Chrome DevTools. when you want to inspect the styles or attributes of a DOM node , right-click the element and select Inspect.
True or False?

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

Cpu time

Hi Experts, If a thread running on CPU needs some data from RAM (from near or far RAM) it requests the data (this moment of time is t0) and gets it in moment of time in t1, and continues his work. Between t0 and t1, while data is transferring from RAM, the thread is goes out from CPU? Is the... (2 Replies)
Discussion started by: sant
2 Replies

2. Shell Programming and Scripting

what would a script include to find CPU's %system time high and user time high?

Hi , I am trying to :wall: my head while scripting ..I am really new to this stuff , never did it before :( . how to find cpu's system high time and user time high in a script?? thanks , help would be appreciated ! :) (9 Replies)
Discussion started by: sushwey
9 Replies

3. Solaris

process CPU time

We are using JAVA program and strange thing is it takes 100% CPU when not in use. The program function is to stream a file on output port (one direction). It checks one directory and when there is a file in it, starts. While it is streaming the CPU usage is normal, about 20%. But, if... (9 Replies)
Discussion started by: orange47
9 Replies

4. UNIX for Advanced & Expert Users

command taking lot of time to execute

Hi, I am running the following command, and it tries to delete some dn from ldap, however, it takes lot of time before it finally request LDAP server to delete it. I am trying to find why it is taking lot of time. Could you anyone help me in this regard. I have copies the pstack output, and... (3 Replies)
Discussion started by: john_prince
3 Replies

5. Shell Programming and Scripting

Why CPU time is longer than Elasped time?

I thought a program's elapsed time, some program language call it real time, should be the time of a program from start to finish. And it should be equal or longer than CPU time. This is true for the most of the cases. However, I do see some of my programs CPU time is longer than Elapsed time. ... (1 Reply)
Discussion started by: visio2000
1 Replies

6. Solaris

Telnet/ssh connection takes a lot of time.

We have three Oracle instances running on our Sun-Blade-T6300. Telnet or SSH connection to one of the instance (or to user oramach) takes a lot of time whether using putty or SecureCRT but connection to any other user is very fast. Any idea what may be causing this slow connection to this... (5 Replies)
Discussion started by: esmgr
5 Replies

7. UNIX for Advanced & Expert Users

how to know which process consume CPU time more

Hi, I have problem like everyday i have to check which process consuming more cpu time. I have done it manually using top command.. Is there any script which will tell the exact process name which will consuming more time. I am using hpux. (1 Reply)
Discussion started by: rajesh08
1 Replies

8. Shell Programming and Scripting

find command takes a lot of time ( can I skip directories)

I have a file called "library" with the following content libnxrdbmgr.a libnxtk.a I am trying to locate if these libraries are on my machine or not. find command runs for about few seconds and hangs after this. Can someone please help me and... (3 Replies)
Discussion started by: knijjar
3 Replies

9. UNIX for Advanced & Expert Users

CPU time on multitask applications

Hello all, I'm using clock() function (from ctime) to realize how long it takes my threaded application to complete an algorithm. I would like to know how this function behaves in multicore boxes, that is: does it return the sum of the clock ticks of each processor the program was runned on ?... (0 Replies)
Discussion started by: clalfa
0 Replies

10. HP-UX

how to calculate CPU time under HP-UX

Hi, I am loking for a c++ function that calculate CPU time under HP-UX Thank you (1 Reply)
Discussion started by: limame
1 Replies

Featured Tech Videos