Since the System partition is not consuming it's whole budget, the DebugReserve partition gets the free cycles and runs 
over budget.

If you had a while 1 thread running in the system partition then the DebugReserve partition would only consume 15% of 
the CPU.

The OS forum would be a better place to ask questions related to APS,

-Joel

________________________________________
From: Gervot Olivier [community-noreply@qnx.com]
Sent: Tuesday, January 06, 2015 11:13 AM
To: general-networking
Subject: Adaptative partitionning

Hi

I am curently testing the adaptative partitionning

I wrote the following test program. It does the following tasks
Try to create a partition
If already created lookup for id
Joint the partition
Consume CPU (while loop)

#include <sys/sched_aps.h>      // sched_aps_partition_info
#include <sys/neutrino.h>       // SchedCtl
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>     // usleep
int main(void) {

        _Int16t id = 0;
        // create a partition
        sched_aps_create_parms creation_data;
        memset(&creation_data, 0, sizeof(creation_data));
        creation_data.budget_percent = 15;
        creation_data.critical_budget_ms = 0;
        creation_data.name = "DebugReserve";
        // Ne peut etre appelle qu'une fois avec un nom donne
        int ret = SchedCtl( SCHED_APS_CREATE_PARTITION, &creation_data, sizeof(creation_data));
        if (ret != EOK)
        {
                printf("Couldn t create partition \"%s\": %s (%d).\n", creation_data.name, strerror(errno), errno);
                // already created

                sched_aps_lookup_parms lookup_data;
                memset(&lookup_data , 0 , sizeof ( lookup_data ) ) ;
                lookup_data.name = "DebugReserve";

                int ret = SchedCtl(SCHED_APS_LOOKUP, &lookup_data, sizeof(lookup_data) );
                if (EOK != ret)
                {
                        printf("err SchedCtl SCHED_APS_LOOKUP ret %d errno %d %s\n",ret, errno, sys_errlist[errno]);
                }
                else
                {
                        //use output field
                        printf("SchedCtl SCHED_APS_LOOKUP OK id %d\n", lookup_data.id);
                        id = lookup_data.id;
                }
        }
        else
        {
                printf ("The new partition ID is %d.\n", creation_data.id);
                id = creation_data.id;
        }

        sched_aps_join_parms join_data;
        memset(&join_data, 0, sizeof(join_data));
        join_data.id = id;
        join_data.pid = 0;
        join_data.tid = 0;
        ret = SchedCtl( SCHED_APS_JOIN_PARTITION, &join_data, sizeof(join_data));
        if (ret != EOK)
        {
                printf("Couldn’t join partition %d: %s (%d).\n",
                                join_data.id, strerror(errno), errno);
        }
        else
        {
                printf ("Process is now in partition %d.\n", join_data.id);
        }
        // Consume max CPU
        while(1)
        {
                //usleep(1);
        }

        return 0;
}

I run both 3 instance of this program

if execute: aps show -v
the display is

                    +----------- CPU Time ------------+-- Critical Time --
                    |        |           Used         |        |
Partition name   id | Budget | 0.100s   1.00s   10.0s | Budget |      Used
--------------------+---------------------------------+-------------------
System            0 |    85% |  0.13%   0.07%   0.23% |  400ms |   0.000ms
DebugReserve      1 |    15% | 74.04%  73.37%  64.13% |    0ms |   0.000ms
--------------------+---------------------------------+-------------------
Total               |   100% | 74.17%  73.44%  64.36% |

The budget for the "DebugReserve" partition is 15% but the program overrun the...