In article <[email protected]>,
Mike Kravetz <[email protected]> wrote:
| On a somewhat related note ...
|
| We (Big Blue) have a performance reporting application that
| would like to know how long a task sits on a runqueue before
| it is actually given the CPU. In other words, it wants to
| know how long the 'runnable task' was delayed due to contention
| for the CPU(s). Of course, one could get an overall feel for
| this based on total runqueue length. However, this app would
| really like this info on a per-task basis.
This is certainly a useful number. It's easy to tell when the CPU is "in
use," but it's not easy to tell when it's "busy" and processes are
waiting for a CPU.
--
bill davidsen <[email protected]>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.
>>>>> "bill" == bill davidsen <[email protected]> writes:
>>>>> "Mike" == Mike Kravetz <[email protected]>
Mike> On a somewhat related note ... We (Big Blue) have a
Mike> performance reporting application that would like to know how
Mike> long a task sits on a runqueue before it is actually given the
Mike> CPU. In other words, it wants to know how long the 'runnable
Mike> task' was delayed due to contention for the CPU(s). Of
Mike> course, one could get an overall feel for this based on total
Mike> runqueue length. However, this app would really like this
Mike> info on a per-task basis.
bill> This is certainly a useful number.
This is exactly what's measured by the microstate accounting patches
I've been pushing to LKML, along with a few other useful statistics.
If you try it, please let me know: see
http://marc.theaimsgroup.com/?l=linux-kernel&m=105884469205748&w=2
--
Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au
You are lost in a maze of BitKeeper repositories, all slightly different.