Re: [linux-audio-user] Problems appling realtime preempt patch to 2.6.12 (general)

On Tue, 12 Jul 2005 12:47:21 -0400
Eric Dantan Rzewnicki <rzewnickie@email-addr-hidden> wrote:

> On Tue, Jul 12, 2005 at 06:11:55PM +0200, Marcel Karras wrote:
> > Hello,
> >
> > I've just joined the list and it's pretty interesting.
> > Can someone tell me something about the differences between the
> > preempt patch from Ingo and the "Realtime Linux Security Module"?
> > I currently use the latter one and I'm quite satisfied as jack works
> > really fast. Perhaps one should try this way instead of the vanilla
> > kernel patch. There have to be pros and cons I'm interested in. Can
> > someone point them out?
>
> The LSM and Ingo's patches are addressing 2 separate issues. Ingo's
> patch is working to minimize sources of latency in various code paths in
> the kernel. The rtlimits and the realtime-lsm are addressing the issue
> of providing a security model for realtime applications to get the
> capabilities they need to run in real-time. Ordinarilly these
> capabilities (CAP_SET_PCAP, mlockall(), and SCHED_FIFO()) are only
> accessible as root. rtlimits and the realtime-lsm provide infrastructure
> for allowing these capabilities to be granted to only a specified set of
> users/processes.

Thank you so far! I've just found an interesting approach to that issue:
http://aplawrence.com/Blog2005/drag4.html

BTW: How can I figure out my current latency time? (are there valuable
benchmark tools?)

Thank you
- Marcel

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