Page fault in Linux 5

[kanis]

We are using RHEL 5(64 bit). We have physical memory as 4GB.
But we are seeing process are using virtual memory even if there are avalable physical memory and causing good amount of page fault.

in RHEL 4(32 bit ) we are not facing this problem .

Any reason ? Is any parameter setting is missing ...

Please help

[coopstah13]

post output of free -m command and vmstat 5 5 from offending machine

[kanis]

free -m
total used free shared buffers cached
Mem: 3776 1313 2462 0 6 27
-/+ buffers/cache: 1278 2497
Swap: 4095 1767 2328

vmstat 5 5
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 1 1809684 2519284 8112 29508 13 11 29 39 14 9 5 3 91 2 0
0 0 1809684 2519284 8140 29528 0 0 0 20 1022 441 1 3 95 2 0
0 0 1809684 2519284 8164 29552 0 0 0 14 1014 433 0 1 99 0 0
0 0 1809684 2518912 8204 29552 0 0 0 33 1016 448 1 2 97 0 0
0 0 1809684 2518912 8220 29552 0 0 0 21 1016 470 0 1 99 0 0

[coopstah13]

you certainly are heavily into swap based on that, though the vmstat doesn't indicate there is a whole lot of swapping going on currently

I'm not sure why so much is in swap, when you definitely have enough free memory

the only thing i can think of is try to mess around with swappiness value, you can see current value in /proc/sys/vm/swappiness

[kanis]

The value is as below
$cat /proc/sys/vm/swappiness
60

[Rubberman]

Depending upon how the system is configured, idle processes can become swapped out, even if there is adequate memory to keep them in core. Why the difference (perceived) between 32-bit and 64-bit I'm not sure.