Re: TLS support

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Mon, Nov 21, 2011 at 10:21:51PM +0000, David Laight wrote:
> On Sat, Nov 19, 2011 at 02:23:20AM +0100, Joerg Sonnenberger wrote:
> > 
> > (1) Register a global variable with the kernel and write
> > curlwp->l_private to that location before returning to userland.
> > 
> > Pro: Relative simple modification of the return-from-trap logic.
> > Con: Has to deal with traps. Requires work for every system call and
> > context switch.
> 
> Why every system call, I'd have thought it would be enough
> to do it on every context switch.

You don't want to trap during a context switch. That's the problem
with using an arbitrary location.

Joerg