lkml.org 
[lkml]   [2006]   [Dec]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] procfs: export context switch counts in /proc/*/stat
From
Date
On Wed, 2006-12-20 at 13:20 +0000, David Wragg wrote:
> "Albert Cahalan" <acahalan@gmail.com> writes:
> > On Mon, Dec 18, 2006 at 11:50:08PM +0000, David Wragg wrote:
> >> This patch (against 2.6.19/2.6.19.1) adds the four context
> >> switch values (voluntary context switches, involuntary
> >> context switches, and the same values accumulated from
> >> terminated child processes) to the end of /proc/*/stat,
> >> similarly to min_flt, maj_flt and the time used values.
> > Hmmm, OK, do people have a use for these values?
>
> My reason for writing the patch was to track which processes are
> active (i.e. got scheduled to run) by polling these context switch
> values. The time used values are not a reliable way to detect process
> activity on fast machines. So for example, when sorting by %CPU, top
> often shows many processes using 0% CPU, despite the fact that these
> processes are running occasionally. If top sorted by (%CPU, context
> switch count delta), it might give a more useful display of which
> processes are active on the system.


if all you care is the number of context switches, you can use the
following system tap script as well:

http://www.fenrus.org/cstop.stp


--
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

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

\
 
 \ /
  Last update: 2006-12-20 14:53    [from the cache]
©2003-2011 Jasper Spaans