Monday, January 23rd, 2012, 2:00 pm
When KDE Eats up the Swap
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N my most powerful desktop I only have 2 gigabytes of RAM. Usually it’s fine for everything to be run simultaneously, but under certain circumstances it’s possible for the swap file to kick in and typically start to be accommodated with active processes, notably KDE applications that exist in view all the time. So I got some scripts together to clean up the swap file and move those processes back to RAM, which makes them quicker (no need for disk I/O).
I have identified processes that typically enter the swap file first and can be restarted uncleanly without loss of data. So I got a script called clean-kde.sh , in which I put:
killall plasma-desktop krunner kmix
kxkb klauncher klipper && plasma-desktop &&
krunner && kmix && klipper && kxkb
&& ~/getswap-sorted.sh
That last one helps show me what other applications have data that still sits in the swap file.
getswap-sorted.sh just has
./getswap.sh | sort -n -k 5
This, in turn, is just a script I found elsewhere. getswap.sh goes as follows
#!/bin/bash
# Get current swap usage for all running processes
# Erik Ljungstrom 27/05/2011
SUM=0
OVERALL=0
for DIR in `find /proc/ -maxdepth 1 -type d | egrep "^/proc/[0-9]"` ; do
PID=`echo $DIR | cut -d / -f 3`
PROGNAME=`ps -p $PID -o comm --no-headers`
for SWAP in `grep Swap $DIR/smaps 2>/dev/null| awk '{ print $2 }'`
do
let SUM=$SUM+$SWAP
done
echo "PID=$PID - Swap used: $SUM - ($PROGNAME )"
let OVERALL=$OVERALL+$SUM
SUM=0
done
echo "Overall swap used: $OVERALL"
That’s about it. The list of swap hoarders helps guide manual restarting of applications that got stuck in the swap file. It’s often worth doing this, even it it takes a couple of minutes. The desktop can stay snappy for months (without a restart of KDE or Linux).
