Re: Inaccurate process time accounting

From: Pavel Machek (pavel@suse.cz)
Date: Fri Jan 21 2000 - 12:24:34 EST

Next message: Alan Cox: "Re: Interesting analysis of linux kernel threading by IBM"
Previous message: William Scott Lockwood III: "Release date"
In reply to: Jan Astalos: "Inaccurate process time accounting"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hi!

> I'm working on monitoring system for Linux clusters and I need to get
> dynamicaly CPU time consumed by process (no matter in which mode) for
> performance prediction. It seems that time accounting in my kernel
> (2.2.14) does not count time slices shorter than one jiffie. I made
> process that runs for less than jiffie and then sleeps one jiffie (in
> cycle). Although benchmarking showed that test takes around 30% of CPU
> time, accounting said that it had consumed less than 1%.
>
> I tested patch from Pavel Machek
> http://www.tux.org/hypermail/linux-kernel/1999week20/0232.html
>
> Results are more accurate but only if there is no other CPU bound
> process.

Yes, that's expected. Main thing I wanted to avoid machine saying 99%
idle if it is in fact 90% busy.
Pavel

-- I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care." Panos Katsaloulis describing me w.r.t. patents me at discuss@linmodems.org

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/

Next message: Alan Cox: "Re: Interesting analysis of linux kernel threading by IBM"
Previous message: William Scott Lockwood III: "Release date"
In reply to: Jan Astalos: "Inaccurate process time accounting"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This archive was generated by hypermail 2b29 : Sun Jan 23 2000 - 21:00:28 EST