On 6/3/21 11:37 AM, Thomas Hartwig wrote:
I am wondering if there is any kernel available by default which offers kernel interrupt timer (CONFIG_HZ) at 1000 Hz. I checked preempt in 15.2 but there it is 250 Hz. Why this is kept at 250 Hz there?
Primarily for historical reasons; 250 Hz was found to be a good compromise between interactive and non-interactive tasks.
My use case is very special: my environment is dealing with high speed cameras and the low frequency is needed to be able to manage high frame speed at several thousand frames per second. Right now I am using a special desktop kernel from a foreign source however I am wondering if there is any chance to have this into mainline LEAP distro available? I know my use case is very special and I should be able to maintain my own kernel for this, however I am wondering if this would be a nice benefit of the LEAP distribution in general and why the preempt kernel is kept at lower frequency still...
Actually this sounds like a case for the realtime kernel. If you have hardware with specific timing needs I would have thought that the driver/application/what have you should be moved to employing a 'realtime' scheduling policy, and manage the frame capture from within the driver rather than relying on the kernel interrupt timer to do it for you. If you had a need for raising the interrupt timer it really sounds like a bad driver design to me ... If, OTOH, you can convert your application to leveraging realtime priority you can look a the -rt kernel, which is geared up for precisely such usecases. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions Germany GmbH, 90409 Nürnberg GF: F. Imendörffer, HRB 36809 (AG Nürnberg)