kern/104406: [ufs] Processes get stuck in "ufs" state under
persistent CPU load
rhurlin at gwdg.de
Thu Nov 1 11:32:59 PDT 2007
Kris Kennaway schrieb:
> Rainer Hurling wrote:
>> Thanks for your answer.
>> Kris Kennaway schrieb:
>>> Rainer Hurling wrote:
>>>> Looking into PR kern/104406 it seems, that this describes exactly
>>>> what I am experiencing on three of my systems over the last weeks.
>>>> They are running FreeBSD 8.0-CURRENT (known as 7.0-CURRENT not long
>>>> ago ;-) ).
>>> Actually it sounds nothing like it at all ;)
>>>> On these machines I often observe hangings, sometimes only a few
>>>> seconds, on other times 20-30 seconds before input/output is back.
>>>> This seems to happen when more extensive disk usage is needed
>>>> (portupgrade, buildworld, browsing complicated websites etc.).
>>>> During the hang even xterm is not responding any more, other
>>>> (diskless) applications like xclock keep to continue. I have no
>>>> panics, only UFS (and MSDOSFS) are mounted, no NTFS. About two
>>>> months ago none of my systems showed these hangings.
>>> Is your system swapping? This is the usual cause of pauses during
>>> high application (actually memory) load.
>> No, I am working with 2GB RAM, without swapping at all.
>> In the meantime I tested the above described behaviour a little more.
>> The hangings even appeared without using Xorg, only working on
>> consoles under heavy disk usage (portupgrade etc.).
> OK, configure the system with the debugger and when it is "hung", break
> to DDB and obtain the data requested in the developers handbook to try
> and investigate what is going on. You may want to do this a few times
> to make sure you capture a representative sample.
I hope to find some time on tomorrow for my first session in kernel
Am I right with chapter 'on-line kernel debugging using ddb'?
What kind of information is most usefull?
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