There appears to be at least a workaround to a problem that's been giving me grief on my BeagleBoard-xM for months now after switching to Ubuntu 10.10.

After running in circles for quite a while without much success, a fix (or at least a workaround) to the problem of 'kevent 2 may have been dropped' messages filling the system logs appears to have been found: increase the minimum amount of free system memory in the kernel. Beyond the problems of large log files, processes were crashing due to out of memory problems and the system would periodically become unresponsive for seconds to minutes any time there was an I/O intensive task running (at least that's when I usually seemed to see it on my system) such as recording or playing back video in MythTV, transferring large files, etc.

The default value is 2884 and the fix appears to be to increase it at least to 4096, though others have had better results with 8192. When I did this, these messages were dramatically reduced but didn't appear to go away entirely so I've been playing with the setting and currently have it set to 12288 and haven't had a single log message or occurrence of the system becoming unresponsive in days.

If you're experiencing this problem and want to temporarily change the setting to see if it works for you, just type the following while logged in as root:

echo 8192 > /proc/sys/vm/min_free_kbytes

The change can be made to persist across reboots by adding the following to /etc/sysctl.conf:

vm.min_free_kbytes = 8192

There doesn't appear to be a magic number that works in every situation, so you might have to play around with the value for your specific situation.