Re: 2.5.74-mm1

On Sunday 06 July 2003 03:28, Jamie Lokier wrote:

Daniel Phillips wrote:

quoted

What are you going to do if you have one
application you want to take priority, re-nice the other 50?

Is that effective?  It might be just the trick.

Point.

quoted

quoted

Something I've often thought would fix this is to allow normal users
to set negative priority which is limited to using X% of the CPU -
i.e. those tasks would have their priority raised if they spent more
than a small proportion of their time using the CPU.

That's essentially SCHED_RR.  As I mentioned above, it's not clear
to me why SCHED_RR requires superuser privilege, since the amount of
CPU you can burn that way is bounded.  Well, the total of all
SCHED_RR processes would need to be bounded as well, which is
straightforward.

Your last point is most important.  At the moment, a SCHED_RR process
with a bug will basically lock up the machine, which is totally
inappropriate for a user app.

How does the lockup come about?  As defined, a single SCHED_RR process could 
lock up only its own slice of CPU, as far as I can see.

Regards,

Daniel

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