On Monday 2012-11-26 17:38, Andrew Wafaa wrote:

On 26 November 2012 16:34, Jan Engelhardt wrote:

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On Monday 2012-11-26 11:53, Andrew Wafaa wrote:

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Could someone provide a link to the RT kernel that is used in SUSE, please? I've looked on OBS but can't find anything. I'd like to see what patches are applied etc, and also to see how it well it works on ARM.

openSUSE does not provide kernel-rt at this time.

That's a shame, is there a way of getting the SLE src.rpm or at least the patches to try and build an openSUSE based kernel-rt?

The patches are available from the RT homepage, and integration with kernel-source is already possible thanks to work from the Kernel team and me; I used to make kernel-rt s, but that was a task that did not have too much ROI. Resolving conflicts against the load of patches that suse-kernel has is time-consuming, especially when it comes to Xen. -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org

Le 26/11/2012 19:19, Greg KH a écrit :

On Mon, Nov 26, 2012 at 10:53:31AM +0000, Andrew Wafaa wrote:

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Could someone provide a link to the RT kernel that is used in SUSE, please? I've looked on OBS but can't find anything. I'd like to see what patches are applied etc, and also to see how it well it works on ARM. Just curious, but why would you want a RT kernel at all, especially on a ARM system? Your overall throughput is usually slower, and unless you have a very specific hardware task, you don't need the latency guarantees that the -rt kernel provides, right?

RT may be wanted for various reasons, _especially_ on ARM systems: * audio related functions * Embedded systems controlling hardware things (motors, etc.) * and much more... Guillaume

thanks,

greg k-h

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On Tue, Nov 27, 2012 at 09:13:48AM +0000, Andrew Wafaa wrote:

Hi Greg,

On 26 November 2012 18:19, Greg KH wrote:

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On Mon, Nov 26, 2012 at 10:53:31AM +0000, Andrew Wafaa wrote:

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Could someone provide a link to the RT kernel that is used in SUSE, please? I've looked on OBS but can't find anything. I'd like to see what patches are applied etc, and also to see how it well it works on ARM.

Just curious, but why would you want a RT kernel at all, especially on a ARM system? Your overall throughput is usually slower, and unless you have a very specific hardware task, you don't need the latency guarantees that the -rt kernel provides, right?

Well, there are a couple of reasons. One is I need to see how the architecture behaves in comparison to others, like MIPS/Power/x86, in different circumstances; two and probably more crucially, we have customers looking at deploying Linux and have a hard requirement for RT.

Bad pun :) Seriously, do they really need RT? Or do they just think they do because they haven't measured what they really want to do and what Linux can provide "out of the box"? There are real reasons to use RT, but they are getting more and more rare and seem to dwarf the actual users of the RT patches that really don't need to do so. Anyway, good luck. greg k-h -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org