Download Driver-to-Program Signal Tester

Download the file archive backfire-0.5.tgz and type:

# tar -zxvf backfire-0.5.tgz
# cd backfire-0.5
# make
# modprobe backfire

Test the principle of the backfire driver:

# head -1 /dev/backfire
0,0
# trap "echo Got signal 7" 7
# echo 7 >/dev/backfire
Got signal 7
# head -1 /dev/backfire
1234567890,123456

Start a measurement loop to check out your kernel's signal sending performance:

# ./sendme -a -p99 -l1000000
Samples:  1000000
To:   Min    0, Cur    0, Avg    1, Max   11
From: Min    2, Cur    3, Avg    3, Max   43

Some more details are given in the respective man pages backfire.4 and sendme.8.