Re: [LAU] rtirq - what does it improve, and how can I measure it?

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]
To: Ralf Mardorf <ralf.mardorf@...>
Cc: A list for linux audio users <linux-audio-user@...>
Date: Tuesday, May 8, 2012 - 1:11 pm

Hi Ralf,

On 05/08/2012 12:14 PM, Ralf Mardorf wrote:

OOPS. Sorry about the typos above. That should have been 'PREEMPT_RT',
'threadirqs' and 'CONFIG_IRQ_FORCED_THREADING'.

>> http://anonscm.debian.org/viewvc/kernel/dists/trunk/linux-2.6/debian/pat...

What is "kernel-rt ex 3.0" ??

https://www.kernel.org/pub/linux/kernel/projects/rt/3.[024] includes
that patch. It's not debian specific but part of Thomas Gleixner's
PREEMPT_RT patch. (It's just that debian's SCM viewer is the only one I
know that allows to read the [PREEMT_RT split quilt queue] patches in a
browser.)

> On AV Linux I run the 3.0.23-avl-7-pae with and the self-build

Correct. IIRC the 'threadirq' option was introduced in vanilla 2.6.39
when a large part of the tasklet-threading code was merged into Linus'
tree. This option was not present for linux-kernels (incl PREEMPT_RT
patched kernels) before 2.6.39.

> But CONFIG_IRQ_FORCED_THREADING has to be set for a kernel-rt too?

You don't really have no choice:

When you configure your kernel with the PREEMPT_RT patch,
PREEMPT_RT_FULL depends on CONFIG_IRQ_FORCED_THREADING and forces it
anyway (PREEMPT_RT_BASE does not).

> spinymouse@precise:~$ grep FORCE /media/avlinux/boot/config-3.0.23-rt40

If you compile a recent kernel (>=3.0) with the PREEMPT_RT patch and set
"CONFIG_IRQ_FORCED_THREADING=y", the boot-option 'threadirqs' is implied
and using it makes no difference.

ciao,
robin
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user

Previous message: [thread] [date] [author]
Next message: [thread] [date] [author]

Messages in current thread:
Re: [LAU] rtirq - what does it improve, and how can I measur..., Robin Gareus, (Tue May 8, 1:11 pm)