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I'm interested in the current usage of cpu - precisely cpu% and wait% - for each thread in a specific application. Is it possible to get that information from somewhere?

I know that top can split information per real thread (ones with pid), but it doesn't show the system/user/wait cpu usage split for each of them. I would also like some way to log that info. Do you know any apps (or apis) that can do that?

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7 Answers 7

Reset to default
5

I'd look into SystemTap. This tool will certainly give you what you want. There is this example of profiling threads; don't know if it has all you want, but you could modify it so that it does.

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24 
top -H -p pid

hope it can help

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14

Percent of cpu usage per thread you can get with ps command:

 ps -emo %cpu,pid,user,args

The way it is calculated is described in ps manpage:

Currently, it is the CPU time used divided by the time the process has been running (cputime/realtime ratio), expressed as a percentage.

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  • I'm really interested in both cpu time and io-wait time. ps can't handle the second one unfortunately.
    – viraptor
    Jul 9, 2009 at 12:41
  • note to self: replace -e by -C java and pid by spid for thread Ids in java app
    – kellogs
    Jan 25, 2015 at 11:12
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    greater note to self: ps -To pcpu,tid -C java | sort -r -k1 | more for hog threads in a java app. ps --sort=pcpu achieves nothing; better rely on shell for the sorting part.
    – kellogs
    Jan 25, 2015 at 11:35
  • 1
    Very useful @kellogs, thanks. I would add -n or -g to sort, so that "10" shows up above "2", for example.
    – EM0
    Nov 8, 2019 at 10:19
  • ...it is the CPU time used divided by the time the process has been running... IMHO usually we need to know the CPU usage over a given period, not over the whole process lifetime. :(
    – pabouk - Ukraine stay strong
    Nov 15, 2023 at 15:23
1

Maybe have a look at htop, you can configure quite a lot with it.

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2
  • unfortunately it cannot split the cpu on user/system/wait time for a specific thread - only for the whole machine
    – viraptor
    Jul 9, 2009 at 12:37
  • Yes, but how would I go about doing that?
    – rmobis
    Feb 4, 2019 at 18:48
0

Did you tried sar? It can fetch a lot of information even on pid level.

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0

Nagios and PNP http://docs.pnp4nagios.org/pnp-0.4/start

Works awesome... little configuration.

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0

I have stumbled on this on a embedded system where we don't have the fancy tools to look in to this stuff.

For this, I have used cpuacct cgroup and placed each thread into its own folder. This way I was able to measure their usage.

Hierarchy was looking like this:

my-app.service
|-tid1
|-tid2
|-tid3

Then I changed it to

my-app.service
|-dir1
|  -tid1
|-dir2
|  -tid2
|-dir3
|  -tid3
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