Subject: Re: -ve RSS back again!
To: Simon Burge <firstname.lastname@example.org>
From: Michael L. Hitch <email@example.com>
Date: 04/28/1999 22:12:18
On Thu, 29 Apr 1999, Simon Burge wrote:
> Just a quick note that I've got some kernel processes with negative RSS
> on my latest (3 day old) 1.4BETA kernel:
> USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND
> root 0 0.0 -119.5 0 -117480 ?? DLs 10:31AM 0:00.03 (swapper)
> root 2 0.0 -119.5 0 -117480 ?? DL 10:31AM 0:00.01 (pagedaemon)
> root 3 0.0 -119.5 0 -117480 ?? DL 10:31AM 0:05.04 (reaper)
> I thought Michael's pmap changes in mips/mips/pmap.c rev 1.52 (from
> early March) had fixed this. Is anyone seeing this problem?
My changes only fix page counts for user processes. The kernel pmap
On mips boxes, doing I/O on character disk devices will decrement the
kernel pmap count: vmapbuf() maps the buffer by directly inserting the
pages into the kernel pmap, but then vunmapbuf() uses uvm_km_free_wakeup()
to remove the mappings - which then decrements the pmap page count.