Re: dhclient taking all cpu

From: Eric Anderson <anderson_at_centtech.com>
Date: Tue, 26 Jul 2005 14:56:36 -0500
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 
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.


Eric




-- 
------------------------------------------------------------------------
Eric Anderson        Sr. Systems Administrator        Centaur Technology
Anything that works is better than anything that doesn't.
------------------------------------------------------------------------
Received on Tue Jul 26 2005 - 17:56:43 UTC

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