[LITMUS^RT] suggestion on reservation_config

[gokul vasan]

Hello,

we are trying to implement Slot shiting algorithm on reservation framework.

I see the the struct reservation_config has a union which specifies the
specific parameters of particular reservation ( currently polling_params,
table_driven), but I presume this would soon become  unreadable when many
other specific reservation arises( like in my case slot_shifting ).
 would  it be better to hold a dynamic array of char, which we can typecast
to the specific structure once we receive at kernel space?

*current implementation : *

struct reservation_config {
        unsigned int id;
        lt_t priority;
        int  cpu;

        union {
                struct {
                        lt_t period;
                        lt_t budget;
                        lt_t relative_deadline;
                        lt_t offset;
                } polling_params;

                struct {
                        lt_t major_cycle_length;
                        unsigned int num_intervals;
                        struct lt_interval __user *intervals;
                } table_driven_params;
        };
}

received by static long pres_reservation_create(int res_type, void* __user
_config)

*Suggested implementation: *

struct reservation_config {
        unsigned int id;
        lt_t priority;
        int  cpu;
        unsigned char data[0]; // dynamic array which holds the reservation
specific data.
  }

struct res_type {
       int type;
        int length; // holds the length of the struct reservation_config.
};

static long pres_reservation_create(struct res_type, void* __user_config)

just a suggestion for maintaining  generic reservation framework.

Thanks and Regards,
Gokul Vasan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.litmus-rt.org/pipermail/litmus-dev/attachments/20141106/77673bdf/attachment.html>