[linux-audio-dev] Fw: Re: Low Latency patches and kernel 2.6.x - Linux-audio-dev

22 Dec 2003

Oops i messed up the quoting a little bit. Here's Morton's answer:

Begin forwarded message:

Date: Mon, 22 Dec 2003 11:58:54 -0800
From: Andrew Morton &lt;akpm(a)osdl.org&gt;
To: Florian Schmidt &lt;mista.tapas(a)gmx.net&gt;
Cc: linux-audio-dev(a)music.columbia.edu,
linux-audio-user(a)music.columbia.edu
Subject: Re: Low Latency patches and kernel 2.6.x

Florian Schmidt &lt;mista.tapas(a)gmx.net&gt; wrote:
...

 Hi Andrew,

 i'm a user of a 2.4.22 kernel patched with the preemption patches plus
 your Low Latency patches. It works very nicely for audio applications
 [like jackd, ardour, etc...]. 
Cool.

...
  Looking into the config menu of the 2.6.0 kernel i
only find a
 "preemptible kernel" config option. Your low latency patches seem not
 to be included. Do you have plans of including your patches in the
 2.6.x kernel? I heard rumors about merging the preemptible and your LL
 patches since they seem to go very nicely together.. Any truth to
 that? 
The objective in 2.6 is that the preemptible kernel achieve similar
worst-case latencies to the low-latency-patched kernel.  So 2.6 should
meet
your requirements out of the box.

That being said, last time I instrumented the 2.6 kernel it was not
achieving the targets.  The specific failure was occurring when the
machine
had a very large number of inodes in cache and the VM system was
reclaiming
those inodes.

It is unlikely that you will strike this problem in real-world usage, so
2.6 should work fine for you.  As ever, testing results would be
appreciated.

(The inode reclaim problem is fairly complex, but I just happen to see a
patch from Dipankar Sarma in my inbox this morning which is designed to
fix
it up).

End forwarded message

-- 
music: http://www.soundclick.com/bands/9/florianschmidt.htm