Can I use VFP in work queue context ?

[Nicolas Pitre]

On Thu, 22 Apr 2010, Woodruff, Richard wrote:

> 
> > From: Nicolas Pitre [mailto:nico at fluxnic.net]
> > Sent: Thursday, April 22, 2010 12:20 PM
> 
> > > If the work queue executes in a unique context it could follow the
> > > same lazy strategy a user space one does.
> >
> > It could... but that begs the question: what is this that requires so
> > much processing power within the kernel?  This really needs to be fully
> > understood and justified before even considering a possible VFP usage in
> > the kernel.
> 
> A simple candidate is Neon memory copy. It can perform much better 
> than the ARM based one. There are a few unfortunate copies associated 
> with some networking devices which see decent benefit.

The benefit is often lost when you need to defer them to a schedulable 
kernel thread though.


Nicolas