[ck] Re: Threading issues? [ck-request@vds.kolivas.org: ck Digest, Vol 3, Issue 16]

[michael at cherryblossom.homelinux.com]

On Mon, Aug 30, 2004 at 08:52:04AM +0200, Ove Kaaven wrote:
> man, 30.08.2004 kl. 02.50 skrev michael at cherryblossom.homelinux.com:
> > > Only root can do this under Linux.
> > 
> > Maybe I sound naive, but would it be possible to get the highest
> > priority supported by the user (root or otherwise) without going to
> > root; getting as close to real-time as possible?
> 
> It's not. Linux only allows non-root processes to reduce its priority,
> not increase it, even for non-real-time priorities. Windows, however,
> allows it for non-real-time priorities.

So the current priority would be the highest priority supported by the
user or process, unless running as root.  Hm.

And I suppose that non-root processes can't decrease priority of other
processes (that aren't threads of said process) owned by the user it's
running under to simulate a higher-priority, or that it would be a bad
idea, right? Does renice count as a process run under said user that
changes the priority of a process?

I suppose there's also the idea of having a single root process or
daemon (probably which would be an optional component) to "increase
performance" by "allowing wine to increase it's priority" by sending the
a said process or daemon a message or signal to tell it to increase the
priority of (a) wine process(es). Of course, if this is a reality, then
we have to debate over whether we want this installed by default, how it
would be configured, communication mechanisms (i.e. Signals, such as
USRSIG1, Unix Sockets, or IP Sockets), coding style, how interrupts and
whatnot are handled, how the daemon can be efficcently designed...  And
then what about people who complain about having too many daemons to
configure and run on their Linux system to do basic tasks...

What about emulating this increasible priority, at the risk of lowering
wine's performance?  Keep the actual real linux priority the same, but
do sleep cycles or slow down the process in some way so that by default
processes run at "Normal", at like, say, 75% (or whatever is the
accepted Windows computed CPU usage) of the thread's assigned/capable
processing power, and then "Idle" or "Low" only running if no other
threads (within wine, or in general) are using the CPU, and then "High"
using 100% of the thread's power?  Or are you guys already saying this?

Of course, This is all speculation, I cannot guarantee the
reasonableness, quality, logicalness, or feasibility of this message.

--Michael Chang