Set project.cpu-shares and Add a New Value

The key points of the example include the following:

• This example is similar to the example shown in Set pool.comment Property and Add New Property.

• Use bcopy(), rather than buffer swapping as in List all the Value-action Pairs for a Specific Resource Control.

• To change the resource control value, call setrctl() with the RCTL_REPLACE flag. The new resource control block is identical to the old resource control block except for the new control value.

  rctlblk_set_value(blk1, nshares);
  if (setrctl("project.cpu-shares", blk2, blk1, RCTL_REPLACE) != 0)

The example gets the project's CPU share allocation, project.cpu-shares, and changes its value to nshares.

/* Omit return value checking/error processing to keep code sample short */
blk1 = malloc(rctlblk_size());
getrctl("project.cpu-shares", NULL, blk1, RCTL_FIRST);
my_shares = rctlblk_get_value(blk1);
printout_my_shares(my_shares);
/* if privileged, do the following to */
/* change project.cpu-shares to "nshares" */
blk1 = malloc(rctlblk_size());
blk2 = malloc(rctlblk_size());
if (getrctl("project.cpu-shares", NULL, blk1, RCTL_FIRST) != 0) {
     perror("getrctl failed");
     exit(1);
}
bcopy(blk1, blk2, rctlblk_size());
rctlblk_set_value(blk1, nshares);
if (setrctl("project.cpu-shares", blk2, blk1, RCTL_REPLACE) != 0) {
     perror("setrctl failed");
     exit(1);
}