Re: no-copy ipc

Hi Bahadir,

I think it is able to ensure "no-copy" because it uses virtual  
registers for IPC communication, you can read more about it at the l4  
x2 reference manual:
http://l4hq.org/docs/manuals/l4-x2-20061117.pdf
section 1.3 (page 11)

Jorge

Quoting bahadir balban <[email protected]>:

> Hi,
>
> How does L4 ensure ipc occurs without copying?
>
> Suppose a sender (S), receiver (R) and an other process (O) is running
> on the system. I would think that during the ipc context switch from
> (S) to (R), registers don't need to be pushed to memory and read back,
> which stands for the "no-copy" part of ipc. Is that correct? If so,
> the system must ensure no context switch to some (O) occurs during the
> time which the message registers are passed from (S) to (R). Would you
> agree? Or am I confusing ipc copying with context switch overhead?
>
> Thanks,
> Bahadir