Re: [dpdk-dev] [PATCH 4/5] net/netvsc: implement link state change callback

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 31 Aug 2018 10:25:47 +0200
Gaëtan Rivet <gaetan.rivet@6wind.com> wrote:

> Hi Stephen,
> 
> On Thu, Aug 30, 2018 at 03:35:11PM -0700, Stephen Hemminger wrote:
> > From: Stephen Hemminger <sthemmin@microsoft.com>
> > 
> > Implement callback functionality on link state changes.
> > This is not really driven off of interrupt file descriptor like most other
> > PMD's. Instead, it happens when a link state change message arrives
> > in the common ring buffer.
> >   
> 
> Does this mean that the lsc event will be processed in a dataplane
> thread? Looking at the _rte_eth_dev_callback_process() call, it seems
> so.
> 
> Shouldn't this be executed in the context of the eal-intr-thread
> instead? This thread is marked control and should be configured with the
> proper afinity, unless dataplane threads.
> 
> Maybe I missed something, it's just to double-check that this will
> behave nicely with applications relying on the eal-intr-thread afinity.
> 
> -- 
> Gaëtan Rivet
> 6WIND

There is no EAL API to take the event and propogate it over to the eal interrupt
thread. The interrupt thread is buried in the internals of EAL.