Re: Softirq priority inversion from "softirq: reduce latencies"

On Sat, 2016-02-27 at 10:19 -0800, Peter Hurley wrote:

Hi Eric,

For a while now, we've been struggling to understand why we've been
observing missed uart rx DMA.

Because both the uart driver (omap8250) and the dmaengine driver
(edma) were (relatively) new, we assumed there was some race between
starting a new rx DMA and processing the previous one.

Hrm, relatively new + tasklet woes rings a bell.  Ah, that..

<quote>
What's worse is that at the point where this code was written it was
already well known that tasklets are a steaming pile of crap and
should die.
</quote>

Source thereof https://lwn.net/Articles/588457/

	-Mike