Re: Current lwp

[Johnny Billquist <bqt%softjar.se@localhost>]

Johnny Billquist wrote:
> While searching for the reason that interrupt sometimes are locked out, 
> I wanted to check what the current lwp is, and I'm confused.
>
> In cpu.h defined curlwp as the contents of the supervisor stack pointer. 
> No problem with that. If supervisor mode isn't used anyway, it's a good 
> register to use for something else.
>
> However, nothing ever sets the supervisor stack pointer to any value. 
> The only time it is set is during boot, when it's set to lwp0, and then 
> nothing more.
>
> But plenty of places reads the current lwp. Does this thing really work? 
> If so, what am I missing? Where is the SSP being set???
>
> As for the missing interrupts, I've come as far as realizing that 
> sometimes mi_switch() will switch to a process, but remain at IPL_SCHED, 
> which obviously will cause my observed problem, but I have not yet 
> figured out under which circumstances this happens.

Doh! Of course. ldpctx sets the SSP.

Hmm, I'll keep digging after my missing interrupts... :-/

        Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol