"Expensive timeout(9) function..."

[Yar Tikhiy]

On Tue, Apr 01, 2003 at 02:37:45PM +0200, Poul-Henning Kamp wrote:
> In message <20030401123319.GA8399 at comp.chem.msu.su>, Yar Tikhiy writes:
> >Hello,
> >
> >I'm getting the following DIAGNOSTIC messages on my -CURRENT box:
> >
> >  Expensive timeout(9) function: 0xc02677e0(0) 0.006095064 s
> >
> >(it's uma_timeout(), which triggers the warning once per boot)
> >
> >  Expensive timeout(9) function: 0xc0141610(0xc0dfcc00) 0.006581587 s
> >  Expensive timeout(9) function: 0xc0141610(0xc0dfcc00) 0.008510173 s
> >
> >(and this one is fxp_tick(); it triggers the warning from time to time)
> >
> >Are those warnings harmless?
> 
> Yes, but indicative of code which needs attention, but harmless.
> 
> >As far as my understanding of the issue reaches, a timeout function
> >is called under protection of the Giant mutex unless it's marked
> >as MP-safe, and that's the reason to spend as little time as possible
> >in it.  Right?
> 
> Yes, but there are other reasons why you would generally not want
> to spend too much time in the timeout function, mostly that it may
> screw up other time-critical things in the system.

Thanks for your explanation!

I hope this little thread will draw the attention of the
responsible or interested parties to the warnings ;-)

-- 
Yar