Re: Getting Started with Hurd-L4

[Espen Skoglund]

[Sam Mason]
> Espen Skoglund wrote:
>> [Marcus Brinkmann]
>>> You have to do this yourself, in your own scheduler
>>> implementation.  L4 only provides the mechanism to change the CPU
>>> a thread runs on, and not which thread should migrate to which CPU
>>> at which time.
>> 
>> Our groupe is pretty actively investigating MP systems (including
>> NUMA and multi-core CPUs) and how to build kernels and systems on
>> top of it.

> I would've thought that L4 couldn't be involved in much of this and
> it would just have to provide this information to the system and
> leave it to do all the work of deciding which threads to migrate
> where.

Well, L4 shouldn't be involved in policy decisions.  You would want to
be able to construct flexible and efficient systems *on top of* L4,
though, and the best way to do this is not entirely obvious.  Also, in
order to build such systems you might need some support from the
kernel itself.  Further, the kernel internals must be designed in a
way that allows it to run efficiently on top of the underlying
hardware.

        eSk