Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3

Ingo Molnar
2007-02-23T10:30:37Z

* Michael K. Edwards <medwards.linux@gmail.com> wrote:

> On 2/22/07, Alan <alan@lxorguk.ukuu.org.uk> wrote:

> > We don't use the FPU in the kernel except in very weird cases where
> > it makes an enormous performance difference. The threadlets also
> > have the same page tables so they have the same %cr3 so its very
> > cheap to switch, basically a predicted jump and some register loads
>
> Do you not understand that real user code touches FPU state at
> unpredictable (to the kernel) junctures? Maybe not in a database or a
> web server, but in the GUIs and web-based monitoring applications that
> are 99% of the potential customers for kernel AIO?
> I have no idea what a %cr3 is, [...]

then please stop wasting Alan's time ...

Ingo