last week I wrote with a problem using r.watershed for basin
deliniation. My elev map is large (rougly 1700 x 750 cells). I am
using a min outside basin of 150 sq. km. The problem is that I do not
have enough mem to run up front. As a result, r.watershed allocates
disk space and swaps to this space within the grass dir. structure.
The code has been running for 4-5 days ( forgot when I started it), and
is nowhere near to being finished.
Jan Hartman responded with a suggestion of redefining SEG_INDEX ( in
ramseg.h ) as a function. I did this to no avail.
The system I am on has a large area set aside for disk swapping
shavano.lance: pstat -s
81912k swap configured
19732k reserved virtual address space
15944k used (4928k text, 96k smem)
65968k free, 3980k wasted, 0k missing
avail: 2054*32k 240*1k
However, r.watershed apparently does not recognize this. In fact,
because it is running in 'slow' mode it is only utilizing 1.0 M of memory
USER PID %CPU %MEM SZ RSS TT STAT TIME COMMAND
de584438 5773 7.8 5.2 1000 600 p0 D N 1473:23 /USH0/GRAD/CE/de584438/grass4
As you can see, this job has been running for a long time, with most of
it spent with disk access.
Can anyone suggest a way for r.watershed to ID the system swap space?
This in itself will allow the job to run much much faster.
I would also appreciate any input some of the CERL programmers might have.
thanks a lot
Dan Epstein