[Bloat] Hardware upticks

[Stephen Hemminger]

On Wed, 6 Jan 2016 01:22:13 +0100
"Steinar H. Gunderson" <sgunderson at bigfoot.com> wrote:

> On Tue, Jan 05, 2016 at 04:06:03PM -0800, Stephen Hemminger wrote:
> > The expensive part is often having to save and restore all the state in
> > registers and other bits on context switch.
> 
> Are you sure? There's not really all that much state to save, and all I've
> been taught before says the opposite.
> 
> Also, I've never ever seen the actual context switch turn up high in a perf
> profile.  Is this because of some sampling artifact?

Yes, especially with Intel processors getting more and more SSE/floating point
registers.