On Thu, 11 Aug 2011, Mahmood Naderan wrote:

quoted

The default behavior is to kill all eligible and unkillable threads until 
there are none left to sacrifice (i.e. all kthreads and OOM_DISABLE).

 
In a simple test with virtualbox, I reduced the amount of ram to 300MB. 
Then I ran "swapoff -a" and opened some applications. I noticed that the free
spaces is kept around 2-3MB and "kswapd" is running. Also I saw that disk
activity was very high. 
That mean although "swap" partition is turned off, "kswapd" was trying to do
something. I wonder how that behavior can be explained?

Despite it's name, kswapd is still active, it's trying to reclaim memory 
to prevent having to kill a process as the last resort.

If /proc/sys/vm/panic_on_oom is not set, as previously mentioned, then 
we'll need the kernel log to diagnose this further.