Hi Roger, Am 30.11.2017 um 10:59 schrieb Roger Oberholtzer: > We have written a minimal kernel interrupt handler for the Raspberry > Pi 3. It is running the current 64-bit Tumbleweed kernel. I am curious > about the rate of interrupts that we might be able to capture. > > The ISR does little other than run when a raising edge interrupt > happens. We are looking at /proc/interrupts to see how many interrupts > have happened. > > We see that at around 23 kHz we begin to loose interrupts. The system > is not doing anything else. > > Does that seem reasonable? I have not seen any good discussion of > this. I think it is rather low. I am guessing that the issue is how > the Linux kernel responds to interrupts. The housework in setting > things up so that the interrupt can run must be the resource hog. > > Opinions? Suggestions?
I don't see anything openSUSE-specific in here, so I'd suggest to ask on upstream linux-rpi-kernel list about any performance expectations. Personally I haven't had any success using GPIO interrupts on my rpi3, but that may be a matter of the device/driver (SX1276) I tried it with. Can you share any more details on DT overlay or driver init you're using to set up the interrupt? What's your interrupt source? Regards, Andreas https://github.com/afaerber/lora-modules/blob/9c5fcb64d7dac953c29da527d0f929efbef4c07e/sx1276.c#L315 -- SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
