Date: Thu, 16 Jun 2005 02:04:42 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: jeremie@le-hen.org Cc: freebsd-current@freebsd.org Subject: Re: incorrect ping(8) interval with powerd(8) Message-ID: <20050616.020442.31252848.imp@bsdimp.com> In-Reply-To: <20050616075743.GE2239@obiwan.tataz.chchile.org> References: <20050616070445.GD2239@obiwan.tataz.chchile.org> <20050616.012302.48201645.imp@bsdimp.com> <20050616075743.GE2239@obiwan.tataz.chchile.org>
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In message: <20050616075743.GE2239@obiwan.tataz.chchile.org>
Jeremie Le Hen <jeremie@le-hen.org> writes:
: > : 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.
Dang, I was hoping it was one of the easy explainations.... Maybe it
is the idle code not waking up fast enough when it has been asleep for
a bit. But that's pure speculation at this point...
Warner
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