Process Priority

QNX Newsgroups (Archives) comp.os.qnx
1

Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

…Stephen

2

On 27 Feb 2004 16:23:05 GMT, Stephen Rasku wrote:

Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

…Stephen

Look at the (undocumented) param member of the inherit structure passed to
spawn(), along with the (undocumented) SPAWN_EXPLICIT_SCHED bit in the
flags (see /usr/include/spawn.h).

This works in 6.21B. I’m not sure why it is undocumented. Perhaps QSSL can
comment?

Rob Rutherford
Ruzz Technology

3

Stephen Rasku wrote:

Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

if you know the name you can use system(“slay slay -P 18 programmName”);

jan

4

In article <c27956$ahp$1@inn.qnx.com>, Jan Rüdiger wrote:

Stephen Rasku wrote:
Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

if you know the name you can use system(“slay slay -P 18 programmName”);

I wasn’t aware of “slay”. Thanks for the tip. We also found a system
call, setprio(), that will work for us.

…Stephen

5

Stephen Rasku wrote:

Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

…Stephen

4th spawn’s argument is a pointer to ‘struct inheritance’ which has the
following fields among others: ‘struct sched_param param’ and ‘int
policy’. I guess that’s what you’re looking for.

6

Stephen Rasku <spr@shaw.ca> wrote:

Is there a way to set the priority of a process (as opposed to a thread)
spawned by spawn() or equivalent programatically? We have a process
manager that spawns numerous programs and we want to modify it so that we
can spawn processes at different priorities.

Or, change your priority first, then spawn the program, as priority is
inherited from parent to child.

-David

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