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
counts.

  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.

Michael