Fiasco lazy-scheduling question

Udo A. Steinberg us15 at
Wed Jan 17 13:03:09 CET 2007

On Wed, 17 Jan 2007 12:51:35 +0100 eschierb at (EKN) wrote:

EKN> For one, the description says that the sender is not removed from 
EKN> the ready-list when the switch is made to the receiver (even 
EKN> though it is now in waiting status). However, as the sender is 
EKN> the active thread it is not part of the ready-list by definition 
EKN> (at least that is how I interpreted the system), so how could 
EKN> it be removed anyway?

I would suggest reading Section 3.3.1 of
which describes and motivates the lazy-queueing invariant.

EKN> Secondly, the switching from sender to receiver is simply an
EKN> execution context switch. If the receiver finishes before 
EKN> the sender's time is up, does the receiver switch the 
EKN> execution context back to that of the sender?

The kernel performs the execution context switch during IPC. If that's what you
meant, then the answer to your question is "yes".


	- Udo

Dipl.-Inf. Udo Steinberg                     
Technische Universität Dresden     
Institute for System Architecture            Tel: +49 351 463 38401
D-01062 Dresden                              Fax: +49 351 463 38284
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