swap_pager complaints but not using swap

Dieter freebsd at sopwith.solgatos.com
Mon Jan 26 21:10:54 PST 2009


In message <200901252247.29775.fbsd.questions at rachie.is-a-geek.net>, Mel writes:
> On Sunday 25 January 2009 04:28:47 Dieter wrote:
> > >>>> AMD64  FreeBSD 7.0  2 GiB main memory
> > >>>>
> 
> > So the machine doesn't normally use swap much at all, but messing with
> > the large ISO apparently kicked something out of memory, and the disk
> > with the swap partition was already busy writing at the other end of
> > the disk.
> >
> > Do you consider writing a large file to disk a "truly unspeakable" load?
> 
> Just curious, since you're running 7.0: SCHED_4BSD or SCHED_ULE? And if you 
> have a chance to change it, does the scenario persist?

kern.sched.name: 4BSD

Right now I'm trying to collect enough info to fix the Seagate 2700.11
firmware fubar.  Once that is resolved, I plan to update to 7.1.  IIRC
7.1 defaults to ULE.  If not I can try switching.  But my understanding
is that the scheduler pays little if any attention to I/O, a holdover
from the days when CPU was the main thing that needed rationing.  These
days it is just the opposite.  CPUs have gotten much much faster, but
I/O is only slightly faster.


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