Matt Dillon wrote:
>
> :
> :Thinking about this a bit more....
> :doesn't each process ahve it's own PTD?, so a process could sleep and
> :another could run but it would have a differnt PTD
> :so they could change that PTDE with impunity
> :because when teh current process runs again it get's its own
> :ptd back again..
>
> Hmm. Ok, I think you are right. APTDpde is what is being loaded
> and that points into the user page table directory page, which is
> per-process. So APTDpde should be per-process.
But it is! (sort-of) APTDpde was per-process but is now per-address-space
with the advent of fork and RFMEM sharing (and KSE).
When we context switch, PTD goes with the process^H^H^H^Haddress space, and
APTD is merely mapped by the last entry in the per-process PTD
(PTD[APTDPDTI] if memory serves correctly).
Cheers,
-Peter
--
Peter Wemm - [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]
"All of this is for nothing if we don't go to the stars" - JMS/B5
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