Improve (potentially halve) login time by using readahead

[gregili]

Before this how to about 35 secs.
After the reboot it did about 8 secs after the login screen.

Really nice ! Thanx...

[loadeddreams]

I mkdir readahead, issue sudo readahead-watch -o readahead/gnome.root, I then login and sudo killall readahead-watch
but there is never a gnome.root file inside of my readahead directory.... just empty file.

readahead-watch did spin the disk the first time ran for about 30 seconds, but from then on it runs instantly.

why is there no gnome.root file?

EDIT: well, using the full directory (/home/user/readahead/gnome.root) seemed to work. not sure why it didn't before, considering I was in my home dir, used sudo and issued it to readahead/gnome.root
but whatever

[jdong]

Try using the full path to your home directory. Relative paths might not work (look for /gnome.root to confirm that suspicion)

[loadeddreams]

yep, you were exactly right. using relative path didn't work, but /gnome.root was empty as well. either way I have it solved now
thanks for the very quick response, and this is a very great post. It worked wonders, even on my very slim laptop setup.

The biggest improvement I saw was with my icons. I use a custom icon pkg that was taking a while to load at start, and I could definitely feel an improvement.

[nickless]

Aww man... I had the same problem missing the gnome.root, but I decided to work on it today. So I log in this morning only to find using compiz my window borders are lost! I really didn't do anything else yesterday... what the hell?
EDIT: Ok fixed that... Compiz disabled Window Decoration... what a way to start the day

[trishacupra]

Now, log out, and press CTRL+ALT+F1 to log into a terminal. Start the profiler:

sudo readahead-watch -o ~/.readahead/gnome.root /

I have a n00bie question. I bet it's painfully obvious but I don't have any experience with this.

I logged out and pressed CTRL+ALT+F1, but all I got was a black screen and a flashing cursor. I couldn't type anything. I gave it a while, but nothing changed, so I had to power down manually. I restarted, tried again, but the same thing happened.

What's supposed to happen when I click CTRL+ALT+F1?

BTW, I'm not pressing the +. Just holding down the CTRL, ALT and F1 buttons together.

[ayates]

Looks like you might have this bug - https://bugs.launchpad.net/bugs/129910

[trishacupra]

Thanks. At least now I know I have a real bug, and I'm not just a n00b.

[double1116]

Hello, thanks for the tip. I modified your 00readahead script to include recording and filtering the list when "profile" is in the kernel command line.

# This script will provide readahead support for an Xsession.
# Place in /etc/X11/Xsession.d/00readahead

# Added by Pat Double

# Check that the package is still installed
if [ -x /sbin/readahead-list ] && [ -x /sbin/readahead-watch ]; then

if grep -qs "profile" /proc/cmdline; then

	# Prepare directory
	[ -d $HOME/.readahead ] || mkdir $HOME/.readahead
	rm $HOME/.readahead/* 2>/dev/null

	# Start future job that will either wait for user (if zenity or xmessage is available) or 30s to save readahead lists
	cat >/tmp/${USER}.readahead.sh <<EOF
#!/bin/sh
if [ -x /usr/bin/zenity ]; then
	sleep 5s
	/usr/bin/zenity --info --text="Your session is being profiled for future speed improvements. Please click OK when your desktop has finished loading."
elif [ -x /usr/bin/xmessage ]; then
	sleep 5s
	/usr/bin/xmessage -center -buttons "Stop" "Your session is being profiled for future speed improvements. Please click Stop when your desktop has finished loading."
else
	sleep 30s
fi

# Stop watching
killall /sbin/readahead-watch
while pidof readahead-watch >/dev/null; do sleep 1s; done

# Filter out large or unuseful files
for F in ${FILES}; do
	while [ ! -e \${F} ]; do sleep 1s; done
	TSZ=0
	while read L; do
		[ -r "\${L}" ] || continue
		[ "\${L#/tmp/}" = "\${L}" ] || continue
		[ "\${L#/var/tmp/}" = "\${L}" ] || continue
		[ "\${L#/var/cache/}" = "\${L}" ] || continue
		LSZ=\$(stat "\${L}" --printf "%s")
		[ \${LSZ} -lt 8000000 ] || continue
		echo "\${L}"
		TSZ=\$(( \${TSZ} + \${LSZ} ))
	done <\${F} >> $HOME/.readahead/\${F#/tmp/${USER}.}
	rm \${F}
	logger -i -t "readahead" "Will readahead \${TSZ} bytes for \${F#/tmp/${USER}.}"
done
rm \$0
EOF
	chmod +x /tmp/${USER}.readahead.sh
	/tmp/${USER}.readahead.sh &

	# Start watching
	FILES="/tmp/${USER}.root"
        /sbin/readahead-watch -o /tmp/${USER}.root /
	if mountpoint -q /home; then
		FILES="${FILES} /tmp/${USER}.home"
                /sbin/readahead-watch -o /tmp/${USER}.home /home
	fi


elif [ -d $HOME/.readahead ]; then

	# Do not background readahead-list as several partitions on the same disk may be
	# referenced and concurrent instances will cause thrashing
	for list in $HOME/.readahead/*; do
	  readahead-list $list
	done
fi

fi # package existance check

[jdong]

Wow, very nice man, that's quite a polished solution. Thanks for posting it