system/rtirq: Added (set priorities on kernel IRQ threads).

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/system/rtirq/README b/system/rtirq/README
new file mode 100644
index 0000000000..17f6b1cd99
--- /dev/null
+++ b/system/rtirq/README
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+rtirq (set priorities on kernel IRQ threads)
+
+The rtirq script is a bash script written by Rui Nuno Capela which works
+in conjunction with the IRQ threading facility of the Linux kernel. The
+script takes advantage of the fact that the kernel can use threads for
+IRQs management, and as such these threads (like any other thread running
+on your system) can be given maximum priority in an effort to minimize
+the latency of audio peripherals.
+
+Modern kernels (3.0 and newer) incorporate IRQ threads, so there's no
+need for a patched kernel on Slackware 14.0 or newer. Older systems
+would need the realtime kernel patch.
+
+The script is installed as /etc/rc.d/rc.rtirq. To actually run it at
+boot time, add code like this to /etc/rc.d/rc.local:
+
+if [ -x /etc/rc.d/rc.rtirq ]; then
+  /etc/rc.d/rc.rtirq start
+fi
+
+The script can be disabled with "chmod -x /etc/rc.d/rc.rtirq".
+
+To enable IRQ threads, the option 'append="threadirqs"' needs to be
+added to the kernel section in /etc/lilo.conf. Example:
+
+# Linux bootable partition config begins
+image = /boot/vmlinuz-huge-3.10.17
+  root = /dev/sda1
+  label = Linux
+  append = "threadirqs"
+  read-only
+# Linux bootable partition config ends
+
+If there's already an 'append', add a space and 'threadirqs', like so:
+  append = "noapic acpi=off threadirqs"
+
+Don't forget to run lilo after editing lilo.conf. The threadirqs option
+will take effect on the next reboot.