dhclient taking all cpu

[Eric Anderson]

Wilko Bulte wrote:
> On Tue, Jul 26, 2005 at 02:56:36PM -0500, Eric Anderson wrote..
> 
>>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.
>>
>>I have the same issue (with ath0).  However, running it in the 
>>foreground doesn't show the problem.  It seems to only break on bootup 
> 
> 
> In my case it does happend with dhclient in the foreground, and on ath(4)
> 
> 
>>for me.  Even running netif stop/start seems ok after I've killed it 
>>initially.  It seems to be bringing ath0 up/down/up/down/etc when it's 
>>hogging CPU.

You know, the second I sent that email, it went crazy.  Looks like it 
was 5 minutes.  But if I kill it, and run with -d, I don't see any extra 
output.

Eric





-- 
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Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
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