Qt-interest Archive, May 2007
thread-priorities on linux based systems
Message 1 in thread
Hi list!
We are working on an application, which uses different threads.
We have two Threads, which we expect to run with high priority and
not be interupted too often: The GUI Thread, and a Protocol Thread,
which receives data from our peripheral devices and acknoleges it.
Several other threads perform less time critical jobs and should run
with low priority. However, it happens that those threads
simultaniously get a lot of work to do and so starve the GUI and the
Protocol thread.
So my questions is, if there is a possibility to use threads with
different
priorities to prevent the two important threads from being interrupted too
often...
thanks in advance for any hints!
kind regards,
Andreas
Message 2 in thread
On Friday 18 May 2007 19:54:34 andreas.sumper@xxxxxxxxxxxx wrote:
> Hi list!
>
> We are working on an application, which uses different threads.
> We have two Threads, which we expect to run with high priority and
> not be interupted too often: The GUI Thread, and a Protocol Thread,
> which receives data from our peripheral devices and acknoleges it.
> Several other threads perform less time critical jobs and should run
> with low priority. However, it happens that those threads
> simultaniously get a lot of work to do and so starve the GUI and the
> Protocol thread.
> So my questions is, if there is a possibility to use threads with
> different
> priorities to prevent the two important threads from being interrupted too
> often...
In theory, it is possible, but in practice it turns out to have negative
consequences:
http://www.trolltech.com/developer/task-tracker/index_html?id=127426&method=entry
We tried to make thread priorities work on Linux systems (the default
scheduling policy on Linux doesn't allow inter-thread priorities), and when
trying to use a different scheduling policy, every thread would preempt every
other process and thread in the entire system as long as the thread was
runnable (i.e. not sleeping).
:/
--
[ signature omitted ]
Message 3 in thread
Hi Bradley!
first of all thanks for your answer!
Right now, we are trying to use two processes. But it is too early to
tell, if this will solve the problem...
never the less thanks!
kind regards,
Andy
Bradley T Hughes <bhughes@xxxxxxxxxxxxx> wrote on 21.05.2007 08:02:13:
> On Friday 18 May 2007 19:54:34 andreas.sumper@xxxxxxxxxxxx wrote:
> > Hi list!
> >
> > We are working on an application, which uses different threads.
> > We have two Threads, which we expect to run with high priority and
> > not be interupted too often: The GUI Thread, and a Protocol Thread,
> > which receives data from our peripheral devices and acknoleges it.
> > Several other threads perform less time critical jobs and should run
> > with low priority. However, it happens that those threads
> > simultaniously get a lot of work to do and so starve the GUI and the
> > Protocol thread.
> > So my questions is, if there is a possibility to use threads with
> > different
> > priorities to prevent the two important threads from being interrupted
too
> > often...
>
> In theory, it is possible, but in practice it turns out to have negative
> consequences:
> http://www.trolltech.com/developer/task-tracker/index_html?
> id=127426&method=entry
>
> We tried to make thread priorities work on Linux systems (the default
> scheduling policy on Linux doesn't allow inter-thread priorities), and
when
> trying to use a different scheduling policy, every thread would preempt
every
> other process and thread in the entire system as long as the thread was
> runnable (i.e. not sleeping).
>
> :/
>
> --
> Bradley T. Hughes - bhughes at trolltech.com
> Trolltech ASA - Sandakervn. 116, P.O. Box 4332 Nydalen, 0402 Oslo,
Norway
