Expensive timeout?

[Robert Watson]

On Wed, 28 Jun 2006, User Freebsd wrote:

> On Wed, 28 Jun 2006, Jonathan Noack wrote:
>
>> Please don't top-post...
>> 
>> User Freebsd wrote:
>>> On Wed, 28 Jun 2006, User Freebsd wrote:
>>>> Just got this on the console of one of hte servers that has been causing 
>>>> problems ...
>>>> 
>>>> Expensive timeout(9) function: 0xc0520e18(0xc8b223a0) 0.296959250 s
>>>> 
>>>> not a very informative error, and that is all that was there, nothing 
>>>> before, nothing after ...
>>> 
>>> Oh, wait, does this have something to do with the Deadlock options I just 
>>> added to the kernel?
>> 
>> Yes, if you look in /sys/kern/kern_timeout.c you'll note that the 
>> "Expensive timeout(9) function" printf is inside an "#ifdef DIAGNOSTIC".
>
> 'k, but is this something that I should be concerned about, or just ignore?

You can convert it to a function name using the addr2line command combining 
the function pointer, 0xc0520e18, with your kernel.debug, then let us know. 
This is an advisory diagnostic message to let developers know a kernel 
function running in a time-critical path is taking too long to run, and is 
worth reporting.  You probably don't want to run with DIAGNOSTIC unless you 
really want to.  INVARIANTS+WITNESS are sufficient for most debugging.

Robert N M Watson
Computer Laboratory
University of Cambridge