Re: incorrect ping(8) interval with powerd(8)

From: Jeremie Le Hen <jeremie_at_le-hen.org>
Date: Thu, 16 Jun 2005 09:57:43 +0200
> : May you delve into this a little bit more please ?  The ping(8) manual
> : page states that the -i flags makes ping(8) to wait a given couple of
> : seconds.  If I use the flags "-i 1", I expect ECHO Requests to be sent
> : with one second between each, whatever the AC line status is.
> : (Note that I didn't explicitely specified "-i 1" in the above example,
> : but this doesn't change the behaviour.)
> 
> Well, the rount trip times went way up (3x longer).  That's normal for
> a 200MHz CPU...  My 333MHz EISA machine can't do much better than
> that.
> 
> But the 2.252s run time is a little longish.  Do you see this
> consistantly?  If you ran it a second time would you get identical
> results.  I've seen ARP take a while...  What else do you have running
> on the system?  Maybe a daemon that takes almost no time at 1.7GHz
> takes a lot longer at 200Mhz and that's starving the ping process...
> Or some driver has gone insane...

Yes, I ran this test multiple times, and I almost get always this same
result although I got 2.208s sometimes, but I don't think this is
significant.

FYI,
my powerd(8) is configured to tastes AC-line four times per seconds.
I tried reducing it's freqency from 4 to 1, but it doesn't change
anything.

ARP is not the culprit, the MAC address is already in cache.

My kernel is compiled with INVARIANTS, but I don't have WITNESS.  My
network interface uses the bge(4) driver.  No firewall rule or complex
network setup.

Anyway this doesn't hurt much.  Thanks for lightening me.

Best regards,
-- 
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >
Received on Thu Jun 16 2005 - 05:57:31 UTC

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