Re: 2.6.9-rc1-bk15-VP-R9 latency traces

[Ingo Molnar <mingo@elte.hu>]

* William Stearns <wstearns@pobox.com> wrote:

> Good day, Ingo,
> 	Thanks for all your work on latency.
> 
> 	I just rebooted my Dell Inspiron 8200 into 2.6.9-rc1-bk15-VP-R9
> (using your bk12-R9 patch on top of bk15).  I got three latency traces
> during boot.  I realize you're not as worried about those, but I thought
> I'd report them anyways.

the boot ones can be pretty bad at times and usually they are not a
worry: there's no user functionality during bootup so latencies have no
ill effects - the bootup itself is one huge 30-60 second latency to the
user!

If they happen during regular use too they are a problem. (not including
latencies that happen when suspending/resuming the laptop.)

> 	The above came from an untainted kernel.  Please let me know if
> you need any more details.  Thanks again for your work.

i'd suggest to reset the latency max via this line in
/etc/rc.d/rc.local:

   echo 30 > /proc/sys/kernel/preempt_max_latency

this way you can delimit the boot-time ones from the ones that happen
later during normal use.

	Ingo