> With 1.3.95 and some kernels before (i don't know exactly when it started)
> I notice unnecessary heavy swapping activity when the system is up some time.
> ...
> As long as the working set does not change everything is normal, but even
> the smallest change results in heavy swapping (while the output of free
> looks normal).
> ...
> What can I do to fine out more about the nature of this problem (yes I will
> try the normal ncr driver...) ?
It may be a problem in the buffer cache management. How big is your buffer
cache when performance is so bad ?
To know if the buffer cache is too small, run 'hdparm -t /dev/hda'. If hdparm
complains, there is one more victim of the page cache vs buffer cache fight...
If you want to join the club, try this :
# dd if=/dev/zero of=foobar bs=$[1024*1024] count=32
32+0 records in
32+0 records out
# cp foobar /dev/null
# hdparm -t /dev/hda
/dev/hda:
Timing buffer-cache reads: 32 MB in 6.03 seconds = 5.31 MB/sec
Timing buffered disk reads: 16 MB in 2.66 seconds = 6.02 MB/sec
Hmm.. suspicious results: probably not enough free memory for a proper test.
-- Benoit