Messages in this thread | | | Date | Mon, 4 Feb 2008 20:44:51 +0100 | From | "Remy Bohmer" <> | Subject | Re: [PATCH -mm v4 6/9] atmel_serial: Split the interrupt handler |
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Hello Haavard,
> That's what I was thinking too. If this is indeed the cause, the > dev_err() added by the debug patch I posted should trigger and we may > consider boosting the priority of the tasklet (using > tasklet_hi_schedule.)
Notice that we are talking about Preempt-RT here. Everything is running in thread context, even tasklets, softirqs etc. They are _all_ preemptible, and if Michael has some RT-thread in the system that has a higher priority than this tasklet or softirq, than the buffer will eventually overflow. I wonder also if Michael has set the RT-priorities correctly, on RT _every_ softirq/irq thread starts by default on priority 50, SCHED_FIFO. If they are still at 50, any other softirq/tasklet, or irq can make this behavior worse. Notice that the default 50 thingy rarely gives a decent behaving system. (But any other default will also give problems anyway, so it _has_ to be customized/tuned by the end user)
Kind Regards,
Remy
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