Re: dhclient taking all cpu

On 7/27/05, Eric Anderson <anderson_at_centtech.com> wrote:
> Eric Anderson wrote:
> > Brooks Davis wrote:
> > 
> >> On Tue, Jul 26, 2005 at 06:53:17PM -0400, Jung-uk Kim wrote:
> >>
> >>> On Tuesday 26 July 2005 04:00 pm, Wilko Bulte wrote:
> >>>
> >>>> On Tue, Jul 26, 2005 at 12:33:24PM -0700, Brooks Davis wrote..
> >>>>
> >>>>
> >>>>> On Mon, Jul 25, 2005 at 10:39:09PM -0400, Mike Jakubik wrote:
> >>>>>
> >>>>>> On Mon, July 25, 2005 9:54 pm, Brooks Davis said:
> >>>>>>
> >>>>>>>>> Probably something wrong with your interface, but you
> >>>>>>>>> havent't provided any useful information so who knows.  At
> >>>>>>>>> the very least, I need to know what interface you are
> >>>>>>>>> running on, something about it's status, and if both
> >>>>>>>>> dhclient processes are running.
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> The interface is xl0 (3Com 3c905C-TX Fast Etherlink XL), and
> >>>>>>>> it worked in this machine fine for as long as i remember.
> >>>>>>>> This seems to have happened since a recent cvsup and
> >>>>>>>> buildworld from ~6-BETA to 7-CURRENT. I rebooted three
> >>>>>>>> times, and the problem occured rougly a minute after bootup.
> >>>>>>>> On the fourth time however, it seems to be ok so far.
> >>>>>>>
> >>>>>>>
> >>>>>>> That sounds like a problem with the code that handles the
> >>>>>>> link state notifications in the interface driver.  The
> >>>>>>> notifications are a reletivly new feature that we're only now
> >>>>>>> starting to use heavily so there are going to be bumps in the
> >>>>>>> road.  It would be intresting to know if you see link state
> >>>>>>> messages promptly if you plug and unplug the network cable.
> >>>>>>
> >>>>>>
> >>>>>> It seems to be back at it again, this time it took longer to
> >>>>>> kick in. Here is a "ps auxw|grep dhclient" :
> >>>>>>
> >>>>>> _dhcp      219 93.5  0.2  1484  1136  ??  Rs    8:49PM  5:06.00 
> >>>>>> dhclient: xl0 (dhclient)
> >>>>>> root       193  0.0  0.2  1484  1088  d0- S     8:49PM  0:00.02 
> >>>>>> dhclient: xl0 [priv] (dhclient)
> >>>>>>
> >>>>>> top:
> >>>>>>
> >>>>>>  PID USERNAME      THR PRI NICE   SIZE    RES STATE    TIME  WCPU 
> >>>>>> COMMAND 219 _dhcp           1 129    0  1484K  1136K RUN    9:33 
> >>>>>> 94.24% dhclient
> >>>>>>
> >>>>>> Nothing in dmesg about link state changes on xl0. Unplugging
> >>>>>> and replugging the network cable results in link state
> >>>>>> notification within a couple seconds.
> >>>>>
> >>>>>
> >>>>> Could you see what happens if you run dhclient in the foreground?
> >>>>> Just running "dhclient -d xl0" should do it.  I'd like to know
> >>>>> what sort of output it's generating.
> >>>>
> >>>>
> >>>> In my case it is not displaying anything:
> >>>>
> >>>>
> >>>> chuck#dhclient -d ath0
> >>>> DHCPREQUEST on ath0 to 255.255.255.255 port 67
> >>>> DHCPACK from 192.168.5.254
> >>>> bound to 192.168.5.20 -- renewal in 21600 seconds.
> >>>>
> >>>> <nothing>
> >>>>
> >>>> I can tell the phenomenon occurs when my laptop fan springs to
> >>>> life:
> >>>>
> >>>> CPU states: 96.5% user,  0.0% nice,  2.7% system,  0.8% interrupt, 
> >>>> 0.0% idle
> >>>> Mem: 48M Active, 28M Inact, 50M Wired, 680K Cache, 34M Buf, 115M
> >>>> Free Swap: 257M Total, 257M Free
> >>>>
> >>>>  PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU
> >>>> COMMAND 719 _dhcp       1 129    0  1384K  1092K RUN      2:14
> >>>> 93.55% dhclient 607 root        1  98    0 34584K 21212K select  
> >>>> 0:09  1.81% Xorg 663 wb          4  20    0 46712K 40224K kserel  
> >>>> 0:27  0.00% mozilla-bin 503 root        1   8    0  1184K   796K
> >>>> nanslp   0:07  0.00% powerd
> >>>>
> >>>> Took (best guess) approx 5-10 minutes for the effect to kick in.
> >>>
> >>>
> >>> FYI, I have the same issues with bge(4) and ndis(4).
> >>
> >>
> >>
> >> I've seen it on ath and em interfaces now, but am not sure what's going
> >> on. and have no idea how to reproduce the problem.  As also reported by
> >> Bakul Shah, we seem to be getting into a state where receive_packet() is
> >> spinning.  I'm not seeing an obvious way for this to be possible.
> > 
> > 
> > It's the latest change to tables.c that breaks it.  Reverting that 
> > single line back, fixes it.
> 
> Sigh.. It ran for about 15 minutes, without problems.  Of course, again, 
> as soon as I hit send, I see dhclient start chugging a moment later.  I 
> suppose it took longer this time since my CPU is already maxed out doing 
> portupgrade.
> 
> So, nevermind.  All I know, is that about 2 weeks ago, it worked just 
> fine.
> 
> Eric

I'm having the same problem, ath on -CURRENT the only new info that
might be useful that I can add right now, is that it wasn't happening
on my 3 - 5 (closer to 3, I think) day old build.

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