Subject: Re: ioflush process
To: Jason R Thorpe <thorpej@wasabisystems.com>
From: Chuck Silvers <chuq@chuq.com>
List: port-alpha
Date: 09/24/2002 23:25:55
On Tue, Sep 24, 2002 at 01:16:41PM -0700, Jason R Thorpe wrote:
> On Tue, Sep 24, 2002 at 09:11:19PM +0200, Riccardo.Veraldi@fi.infn.it wrote:
> 
>  > the same also for other kernel related processes which gets 10% of memory
>  > each. I had not notices this behaviour on NetBSD-1.5.x
>  > 
>  > dijkstra: {19} ps -auwx | sort +4 | less
>  > root      2  0.0 10.9     0 17712 ?? DK    1:50PM  0:00.00 [scsibus0]
>  > root      3  0.0 10.9     0 17712 ?? DK    1:50PM  0:00.67 [pagedaemon]
>  > root      6  0.0 10.9     0 17712 ?? DK    1:50PM  0:00.81 [aiodoned]
>  > root      4  0.0 10.9     0 17712 ?? DK    1:50PM  0:02.32 [reaper]
>  > root      5  0.0 10.9     0 17712 ?? DK    1:50PM  1:15.71 [ioflush]
>  > root      0  0.0 10.9     0 17712 ?? DKs   1:50PM  0:00.15 [swapper]
>  > 
>  > is all this normal?
>  > thanks
> 
> Note... They each look like they consume 10% of memory .. but in fact
> all of the "kernel processes" (like the ones listed here) share the
> same address space (the kernel address space), and thus it is only a
> single 10%.


and to muddy the waters even further, this is just UVM-managed physical memory
that the kernel happens to have mapped.  this doesn't count the buffer cache
or some other types of memory that the kernel uses, but it does count
(some) cached file data that may also be mapped into applications.
in short, this number doesn't mean all that much.

-Chuck