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

From: Francois Romieu
Date: Sun Feb 28 2016 - 12:01:36 EST

Mike Galbraith <umgwanakikbuti@xxxxxxxxx> :
> 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

tasklets are ingrained in the dmaengine API (see Documentation/dmaengine/client.txt
and drivers/dma/virt-dma.h::vchan_cookie_complete).

Moving everything to irq context or handling his own sub-{jiffy/ms} timer
while losing async dma doesn't exactly smell like roses either. :o(