dhclient taking all cpu

Wed Jul 27 19:57:24 GMT 2005

On Wed, Jul 27, 2005 at 02:47:21PM -0500, Eric Anderson wrote:
> Brooks Davis wrote:
> >On Wed, Jul 27, 2005 at 02:35:06PM -0500, Eric Anderson wrote:
> >
> >>Brooks Davis wrote:
> >>
> >>>On Tue, Jul 26, 2005 at 04:39:33PM -0700, 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.
> >>>
> >>>
> >>>I think I've found it.  There was a really odd typo (= instead of +) in
> >>>the code that handles undersized captures on the bpf socket.  Please try
> >>>the following patch and see if it solves the problem.  I'm testing here,
> >>>but I don't have a reliable way to trigger the bug.  The fix is fairly
> >>>obvious so I'll commit it to head shortly.
> >>
> >>It's been 20 minutes without any issues - I think that did it.  Thanks!
> >
> >
> >Great!  Thanks for the report.
> 
> I give up.  Now it's back to it's dirty ways.  Ran for 22 mins without 
> issue (with -d option), so I reran without the -d, and it spiked within 
> a few minutes.
> 
> 
> I'll now wait until someone else claims it works before commenting on it 
> since my computer seems to enjou making me look bad. :)

Crap.  You did remember to install the patched version before running it
the normal way, right?

If you could compile it with debugging and get me a dump and executable
that would help.

-- Brooks

-- 
Any statement of the form "X is the one, true Y" is FALSE.
PGP fingerprint 655D 519C 26A7 82E7 2529  9BF0 5D8E 8BE9 F238 1AD4
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