Re: [Syllable-kernel] Possible scheduler patch

[Daniel G. <da...@fp...>]

On Wed, 2005-01-12 at 19:26 +0000, Kristian Van Der Vliet wrote:
> This scheme turned out to be tricky to implement, with no real benefit over 
> the current scheme.  It suffered from a "ping pong" problem where the dynamic 
> priority would ping-pong between two values as the algorithm fought over 
> itself.  Certain threads were also very suseptable to what appeared to be 
> priority inversion E.g. the desktop thread at login would use a large amount 
> of CPU time, get down to a certain low priority and then hang, likely 
> deadlocked with another thread.  The testcase showed less of an improvement 
> also, so the net benefit was smaller.
> 
> I didn't get more testing done as I really need to rebuild my machine; it has 
> remnants of Glibc 2.3.3 testing on it which are playing havoc.  Once I've got 
> it back to a clean state I'll get back to fiddling with some different ideas.
> 

So, I fared a bit better than you did.  I could log in, and use by box
normally, as far as I could tell.  However, if I tried to run a sync
command, the box locked up, with nothing being printed in the kernel
log.  This was repeatable: sync -> lockup.  Of course, neither the
original kernel nor your hacked up one caused such a lockup.

Back to the drawing board, I guess.

(If anyone's interested, I can post my patches...)

On a side note, has anyone gotten sshd working?  It would make
development, if not testing, easier.

Daniel