Re: [PATCH RFC] blk-mq: Don't IPI requests on PREEMPT_RT

[Christoph Hellwig]

On Tue, Oct 27, 2020 at 11:11:02AM +0100, Sebastian Andrzej Siewior wrote:
> Right. I found this David Runge's log:

True, ->bi_end_io instances can do a lot of things as long as they
are hardirq safe.

And in the end the IPI case isn't the super fast path anyway, as it
means we don't use a queue per CPU.

Is there a way to raise a softirq and preferably place it on a given
CPU without our IPI dance?  That should be a win-win situation for
everyone.