Re: excessive kworker activity when idle. (was Re: vma corruption intoday's -git)

From: Arnaldo Carvalho de Melo
Date: Thu Mar 31 2011 - 10:21:49 EST


Em Wed, Mar 30, 2011 at 10:32:11PM -0700, Linus Torvalds escreveu:
> On Wed, Mar 30, 2011 at 8:55 PM, Dave Jones <davej@xxxxxxxxxx> wrote:
> > I tried that, and wasn't particularly enlightened.
> >
> > +      6.53%  kworker/1:2  [kernel.kallsyms]  [k] read_hpet
> > +      4.83%  kworker/0:0  [kernel.kallsyms]  [k] read_hpet
>
> Go into those, deeper into the callchain. That's how to see what the
> upper-level problem is - by seeing who actually calls it. The leafs
> themselves (where the time is obviously spent) don't tend to be very
> informative, no.

Yeah, please press 'E' since you're using the TUI, where you can expand
collapse callchains in all its levels.

Pressing 'E' will expand all of them, 'C' will collapse it all. Enter on
lines with a '+' will expand just that one, etc.

Press 'h' to get more help.

Or use 'perf report --stdio' and you'll get it all expanded and in plain
text.

- Arnaldo
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