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priocntl(2)                      System Calls                      priocntl(2)



NAME
       priocntl - process scheduler control

SYNOPSIS
       #include <sys/types.h>
       #include <sys/priocntl.h>
       #include <sys/rtpriocntl.h>
       #include <sys/tspriocntl.h>
       #include <sys/fsspriocntl.h>
       #include <sys/fxpriocntl.h>

       long priocntl(idtype_t idtype, id_t id, int cmd, /* arg */ ...);

DESCRIPTION
       The  priocntl() function provides for control over the scheduling of an
       active light weight process (LWP).

       LWPs fall into distinct  classes  with  a  separate  scheduling  policy
       applied to each class. The classes currently supported are the realtime
       class, the time-sharing class, the fair-share class, and the fixed-pri-
       ority  class.  The characteristics of these classes are described under
       the corresponding headings below.

       The class attribute of an LWP is inherited across the fork(2)  function
       and  the  exec(2)  family  of functions. The priocntl() function can be
       used to dynamically change the class and  other  scheduling  parameters
       associated with a running LWP or set of LWPs given the appropriate per-
       missions as explained below.

       In the default configuration, a runnable realtime LWP runs  before  any
       other LWP. Therefore, inappropriate use of realtime LWP can have a dra-
       matic negative impact on system performance.

       The priocntl() function provides an interface for specifying a process,
       set  of  processes, or an LWP to which the function applies. The prioc-
       ntlset(2) function provides  the  same  functions  as  priocntl(),  but
       allows a more general interface for specifying the set of LWPs to which
       the function is to apply.

       For priocntl(), the idtype and id arguments are used together to  spec-
       ify  the  set of LWPs. The interpretation of id depends on the value of
       idtype. The possible values for idtype  and  corresponding  interpreta-
       tions of id are as follows:

       P_ALL           The  priocntl()  function applies to all existing LWPs.
                       The value of id is ignored. The permission restrictions
                       described below still apply.



       P_CID           The  id  argument is a class ID (returned by the prioc-
                       ntl() PC_GETCID command as explained below). The prioc-
                       ntl()  function  applies  to  all LWPs in the specified
                       class.



       P_GID           The id argument is a group ID. The priocntl()  function
                       applies to all LWPs with this effective group ID.



       P_LWPID         The  id  argument  is  an LWP ID. The priocntl function
                       applies to the LWP with the  specified  ID  within  the
                       calling process.



       P_PGID          The  id  argument is a process group ID. The priocntl()
                       function applies to all LWPs currently associated  with
                       processes in the specified process group.



       P_PID           The  id  argument  is  a process ID specifying a single
                       process. The priocntl() function applies  to  all  LWPs
                       currently associated with the specified process.



       P_PPID          The  id argument is a parent process ID. The priocntl()
                       function applies to all LWPs currently associated  with
                       processes with the specified parent process ID.



       P_PROJID        The  id  argument is a project ID. The priocntl() func-
                       tion applies to all LWPs with this project ID.



       P_SID           The id argument is a session ID. The  priocntl()  func-
                       tion applies to all LWPs currently associated with pro-
                       cesses in the specified session.



       P_TASKID        The id argument is a task ID. The  priocntl()  function
                       applies to all LWPs currently associated with processes
                       in the specified task.



       P_UID           The id argument is a user ID. The  priocntl()  function
                       applies to all LWPs with this effective user ID.



       P_ZONEID        The  id  argument is a zone ID. The priocntl() function
                       applies to all LWPs with this zone ID.



       P_CTID          The id argument is a process contract  ID.  The  prioc-
                       ntl()  function  applies  to all LWPs with this process
                       contract ID.



       An id value of P_MYID can be used in conjunction with the idtype  value
       to specify the LWP ID, parent process ID, process group ID, session ID,
       task ID, class ID, user ID, group ID, project ID, zone ID,  or  process
       contract ID of the calling LWP.

       To change the scheduling parameters of an LWP (using the PC_SETPARMS or
       PC_SETXPARMS command as explained below) , the real or  effective  user
       ID of the LWP calling priocntl() must match the real or the calling LWP
       must have sufficient privileges.   These  are  the  minimum  permission
       requirements enforced for all classes. An individual class might impose
       additional permissions requirements when setting  LWPs  to  that  class
       and/or when setting class-specific scheduling parameters.

       A special SYS scheduling class exists for the purpose of scheduling the
       execution of certain special system  processes  (such  as  the  swapper
       process).  It is not possible to change the class of any LWP to SYS. In
       addition, any processes in the SYS class that are included in a  speci-
       fied  set  of processes are disregarded by  priocntl(). For example, an
       idtype of P_UID and an id value of 0 would specify all processes with a
       user  ID  of  0  except processes in the SYS class and (if changing the
       parameters using PC_SETPARMS or PC_SETXPARMS) the  init(1M) process.

       The init process is a special case. For a priocntl() call to change the
       class  or  other  scheduling parameters of the init process (process ID
       1), it must be the only process specified by idtype and id.   The  init
       process  can be assigned to any class configured on the system, but the
       time-sharing class is almost  always  the  appropriate  choice.  (Other
       choices  might  be  highly  undesirable.  See the System Administration
       Guide: Basic Administration for more information.)

       The data type and value of arg are specific  to  the  type  of  command
       specified by cmd.

       A pcinfo_t structure with the following members, defined in <&lt;sys/prioc-
       ntl.h>&gt;, is used by the PC_GETCID and PC_GETCLINFO commands.

       id_t   pc_cid;                   /* Class id */
       char   pc_clname[PC_CLNMSZ];     /* Class name */
       int    pc_clinfo[PC_CLINFOSZ];   /* Class information */



       The pc_cid member is a class ID returned by  the  priocntl()  PC_GETCID
       command.   The  pc_clname member is a buffer of size PC_CLNMSZ, defined
       in <&lt;sys/priocntl.h>&gt;, used to hold the class name: RT for  realtime,  TS
       for time-sharing, or FX for fixed-priority.

       The  pc_clinfo  member  is  a  buffer  of  size PC_CLINFOSZ, defined in
       <&lt;sys/priocntl.h>&gt;, used to return data describing the  attributes  of  a
       specific  class.  The  format  of  this  data  is class-specific and is
       described under the appropriate heading (REALTIME  CLASS,  TIME-SHARING
       CLASS, or FIXED-PRIORITY CLASS) below.

       A  pcparms_t structure with the following members, defined in <&lt;sys/pri-
       ocntl.h>&gt;, is used by the PC_SETPARMS and PC_GETPARMS commands.

       id_t  pc_cid;                   /* LWP class */
       int   pc_clparms[PC_CLPARMSZ];  /* Class-specific params */



       The pc_cid member is a class ID returned by  the  priocntl()  PC_GETCID
       command.  The special class ID PC_CLNULL can also be assigned to pc_cid
       when using the PC_GETPARMS command as explained below.

       The pc_clparms buffer holds class-specific scheduling  parameters.  The
       format of this parameter data for a particular class is described under
       the appropriate  heading  below.  PC_CLPARMSZ  is  the  length  of  the
       pc_clparms buffer and is defined in <&lt;sys/priocntl.h>&gt;.

       The PC_SETXPARMS and PC_GETXPARMS commands exploit the varargs declara-
       tion of priocntl(). The argument following the command code is a  class
       name:  RT  for realtime, TS for time-sharing, or FX for fixed-priority.
       The parameters  after the class name build  a  chain  of  (key,  value)
       pairs,  where  the  key  determines the meaning of the value within the
       pair. When using PC_GETXPARMS, the value associated  with  the  key  is
       always  a  pointer  to a scheduling parameter.  In contrast, when using
       PC_SETXPARMS the scheduling parameter is given as a  direct  value.   A
       key  value  of 0 terminates the sequence and all further keys or values
       are ignored.

       The  PC_SETXPARMS  and  PC_GETXPARMS   commands   are   more   flexible
       thanPC_SETPARMS  and  PC_GETPARMS  and  should  replace PC_SETPARMS and
       PC_GETPARMS on a long-term basis.

COMMANDS
       Available priocntl() commands are:

       PC_ADMIN        This command  provides  functionality  needed  for  the
                       implementation  of the dispadmin(1M) utility. It is not
                       intended for general use by other applications.



       PC_DONICE       Set or get nice value of the specified  LWP(s)  associ-
                       ated  with the specified process(es). When this command
                       is used with the idtype of P_LWPID, it  sets  the  nice
                       value  of  the LWP. The arg argument points to a struc-
                       ture of type pcnice_t. The pc_val member specifies  the
                       nice  value  and  the  pc_op  specifies the type of the
                       operation.

                       When pc_op is set to PC_GETNICE,  priocntl()  sets  the
                       pc_val to the highest priority (lowest numerical value)
                       pertaining to any of the specified LWPs.

                       When pc_op is set to PC_SETNICE,  priocntl()  sets  the
                       nice  value  of  all  LWPs  in the specified set to the
                       value specified in pc_val member of pcnice_t structure.

                       The priocntl() function returns -1 with  errno  set  to
                       EPERM  if the calling LWP doesn't have appropriate per-
                       missions to set or get nice values for one or  more  of
                       the  target  LWPs.  If  priocntl()  encounters an error
                       other than permissions, it does  not  continue  through
                       the  set  of  target LWPs but returns the error immedi-
                       ately.



       PC_GETCID       Get class ID and class attributes for a specific  class
                       given  the  class name. The idtype and id arguments are
                       ignored. If arg is non-null, it points to  a  structure
                       of  type  pcinfo_t.  The  pc_clname buffer contains the
                       name of the class whose attributes you are getting.

                       On success, the class ID is  returned  in  pc_cid,  the
                       class  attributes are returned in the pc_clinfo buffer,
                       and the priocntl() call returns  the  total  number  of
                       classes  configured  in  the  system (including the sys
                       class). If the class specified by pc_clname is  invalid
                       or  is  not  currently  configured, the priocntl() call
                       returns -1 with errno set to EINVAL. The format of  the
                       attribute data returned for a given class is defined in
                       the    <&lt;sys/rtpriocntl.h>&gt;,    <&lt;sys/tspriocntl.h>&gt;,    or
                       <&lt;sys/fxpriocntl.h>&gt;   header  and  described  under  the
                       appropriate heading below.

                       If arg is a null pointer, no attribute data is returned
                       but  the  priocntl()  call  still returns the number of
                       configured classes.



       PC_GETCLINFO    Get class name and  class  attributes  for  a  specific
                       class  given  class ID. The idtype and id arguments are
                       ignored. If arg is non-null, it points to  a  structure
                       of  type pcinfo_t. The pc_cid member is the class ID of
                       the class whose attributes you are getting.

                       On success, the class name is returned in the pc_clname
                       buffer,  the  class  attributes  are  returned  in  the
                       pc_clinfo buffer, and the priocntl() call  returns  the
                       total  number  of  classes  configured  in  the  system
                       (including the sys class). The format of the  attribute
                       data  returned  for  a  given  class  is defined in the
                       <&lt;sys/rtpriocntl.h>&gt;, <&lt;sys/tspriocntl.h>&gt;, or  <&lt;sys/fxpri-
                       ocntl.h>&gt;  header  and  described  under the appropriate
                       heading below.

                       If arg is a null pointer, no attribute data is returned
                       but  the  priocntl()  call  still returns the number of
                       configured classes.



       PC_GETPARMS     Get the class and/or class-specific scheduling  parame-
                       ters of an LWP. The arg member points to a structure of
                       type pcparms_t.

                       If pc_cid specifies a configured class and a single LWP
                       belonging to that class is specified  by the idtype and
                       id values or the procset structure, then the scheduling
                       parameters  of  that LWP are returned in the pc_clparms
                       buffer. If the LWP specified does not exist or does not
                       belong  to  the  specified  class,  the priocntl() call
                       returns -1 with errno set to ESRCH.

                       If pc_cid specifies a configured class  and  a  set  of
                       LWPs  is specified, the scheduling parameters of one of
                       the specified LWP belonging to the specified class  are
                       returned  in  the  pc_clparms buffer and the priocntl()
                       call returns the process ID of the  selected  LWP.  The
                       criteria for selecting an LWP to return in this case is
                       class-dependent. If none of the specified LWPs exist or
                       none  of them belong to the specified class, the prioc-
                       ntl() call returns -1 with errno set to ESRCH.

                       If pc_cid is PC_CLNULL and a single LWP  is  specified,
                       the  class  of  the specified LWP is returned in pc_cid
                       and its  scheduling  parameters  are  returned  in  the
                       pc_clparms buffer.



       PC_GETXPARMS    Get  the  class or class-specific scheduling parameters
                       of  an  LWP.  The  class  name  (first  argument  after
                       PC_GETXPARMS)  specifies the class and the (key, value)
                       pair sequence contains a pointer to the  class-specific
                       parameters.  The  keys  and the types of the class-spe-
                       cific parameter data  are described below and can  also
                       be  found  in  the class-specific headers <&lt;sys/rtprioc-
                       ntl.h>&gt;, <&lt;sys/tspriocntl.h>&gt;, and <&lt;sys/fxpriocntl.h>&gt;.  If
                       the  specified class is a configured class and a single
                       LWP belonging to that class is specified by the  idtype
                       and id values or the procset structure, then the sched-
                       uling parameters of that LWP are returned in the  given
                       (key,  value)  pair  buffers. If the LWP specified does
                       not exist or does not belong to  the  specified  class,
                       priocntl() returns -1 and errno is set to ESRCH.

                       If  the  class  name specifies a configured class and a
                       set of LWPs is given, the scheduling parameters of  one
                       of  the specified LWPs belonging to the specified class
                       are  returned  and  the  priocntl()  call  returns  the
                       process  ID  of  the  selected  LWP.  The  criteria for
                       selecting an LWP to return in this case is class-depen-
                       dent.  If  none  of the specified LWPs exist or none of
                       them belong to the specified class, priocntl()  returns
                       -1 and errno is set to ESRCH.

                       If  the  class name is a null pointer, a single process
                       or LWP is specified, and a  (key,  value)  pair  for  a
                       class  name request is given, priocntl() fills the buf-
                       fer pointed to by value with  the  class  name  of  the
                       specified  process  or  LWP. The key for the class name
                       request is  PC_KY_CLNAME  and  the  class  name  buffer
                       should be declared as:

                       char   pc_clname[PC_CLNMSZ];     /* Class name */




       PC_SETPARMS     Set  the class and class-specific scheduling parameters
                       of the specified LWP(s) associated with  the  specified
                       process(es). When this command is used with the  idtype
                       of P_LWPID, it will set the  class  and  class-specific
                       scheduling  parameters  of  the  LWP.  The arg argument
                       points to a structure of  type  pcparms_t.  The  pc_cid
                       member  specifies  the  class  you  are setting and the
                       pc_clparms buffer contains the  class-specific  parame-
                       ters you are setting.  The format of the class-specific
                       parameter data is defined  in  the  <&lt;sys/rtpriocntl.h>&gt;,
                       <&lt;sys/tspriocntl.h>&gt;,  or  <&lt;sys/fxpriocntl.h>&gt;  header and
                       described under the appropriate class heading below.

                       When setting parameters for a set of  LWPs,  priocntl()
                       acts  on  the LWPs in the set in an implementation-spe-
                       cific order. If priocntl() encounters an error for  one
                       or  more of the target processes, it might or might not
                       continue through the set  of  LWPs,  depending  on  the
                       nature of the error. If the error is related to permis-
                       sions (EPERM), priocntl()  continues  through  the  LWP
                       set,  resetting  the parameters for all target LWPs for
                       which the calling LWP has appropriate permissions.  The
                       priocntl()  function  then returns -1 with errno set to
                       EPERM to indicate that the operation failed for one  or
                       more  of  the  target LWPs. If priocntl() encounters an
                       error other than  permissions,  it  does  not  continue
                       through  the  set  of target LWPs but returns the error
                       immediately.



       PC_SETXPARMS    Set the class and class-specific scheduling  parameters
                       of  the specified LWP(s)  associated with the specified
                       process(es). When this command is used with P_LWPID  as
                       idtype, it will set the class and class-specific sched-
                       uling parameters of the  LWP.  The  class  name  (first
                       argument  after PC_SETXPARMS) specifies the class to be
                       changed and the following (key,  value)  pair  sequence
                       contains  the  class-specific parameters to be changed.
                       Only those (key,value) pairs whose scheduling  behavior
                       is  to change must be specified. The keys and the types
                       of the  class-specific  parameter  data  are  described
                       below  and  can  also  be  found  in the class-specific
                       header  files  <&lt;sys/rtpriocntl.h>&gt;,  <&lt;sys/tspriocntl.h>&gt;,
                       and <&lt;sys/fxpriocntl.h>&gt;.

                       When  setting  parameters for a set of LWPs, priocntl()
                       acts on the LWPs in the set in  an  implementation-spe-
                       cific  order. If priocntl() encounters an error for one
                       or more of the target processes, it might or might  not
                       continue  through  the  set  of  LWPs, depending on the
                       nature of the error. If the error is related to permis-
                       sions (EPERM), priocntl() continues to reset the param-
                       eters for all target LWPs where  the  calling  LWP  has
                       appropriate   permissions.   The   priocntl()  function
                       returns -1 and errno is set to EPERM when the operation
                       failed  for  one or more of the target LWPs. All errors
                       other than EPERM result in an immediate termination  of
                       priocntl().



REALTIME CLASS
       The realtime class provides a fixed priority preemptive scheduling pol-
       icy for those LWPS requiring fast and deterministic response and  abso-
       lute user/application control of scheduling priorities. If the realtime
       class is configured in the system, it should have exclusive control  of
       the  highest range of scheduling priorities on the system. This ensures
       that a runnable realtime LWP  is  given  CPU  service  before  any  LWP
       belonging to any other class.

       The  realtime  class  has  a range of realtime priority (rt_pri) values
       that can be assigned to an LWP within the  class.  Realtime  priorities
       range  from  0  to  x,  where the value of x is configurable and can be
       determined for a specific installation by using the priocntl()  PC_GET-
       CID or PC_GETCLINFO command.

       The realtime scheduling policy is a fixed priority policy. The schedul-
       ing priority of a realtime LWP is never changed except as the result of
       an  explicit request by the user/application to change the rt_pri value
       of the LWP.

       For an LWP in the realtime class, the rt_pri value is, for all  practi-
       cal  purposes,  equivalent  to  the scheduling priority of the LWP. The
       rt_pri value completely determines the scheduling priority of  a  real-
       time  LWP  relative  to other LWPs within its class. Numerically higher
       rt_pri values represent higher priorities.  Since  the  realtime  class
       controls  the  highest range of scheduling priorities in the system, it
       is guaranteed that the runnable realtime LWP with  the  highest  rt_pri
       value is always selected to run before any other LWPs in the system.

       In addition to providing control over priority, priocntl() provides for
       control over the length of the time quantum allotted to the LWP in  the
       realtime  class. The time quantum value specifies the maximum amount of
       time an LWP can run assuming that it  does  not  complete  or  enter  a
       resource  or  event wait state (sleep). If another LWP becomes runnable
       at a higher priority, the currently  running  LWP  might  be  preempted
       before receiving its full time quantum.

       The realtime quantum signal can be used for the notification of runaway
       realtime processes about the consumption of their time  quantum.  Those
       processes,  which  are  monitored  by the realtime time quantum signal,
       receive the configured signal in the event of time quantum  expiration.
       The  default value (0) of the time quantum signal will denote no signal
       delivery and a positive value will denote the delivery  of  the  signal
       specified by the value. The realtime quantum signal can be set with the
       priocntl() PC_SETXPARMS  command  and  displayed  with  the  priocntl()
       PC_GETXPARMS command as explained below.

       The  system's  process  scheduler keeps the runnable realtime LWPs on a
       set of scheduling queues. There is a separate queue for each configured
       realtime  priority  and all realtime LWPs with a given rt_pri value are
       kept together on the appropriate queue. The LWPs on a given  queue  are
       ordered  in  FIFO order (that is, the LWP at the front of the queue has
       been waiting longest for service and receives the CPU first).  Realtime
       LWPs  that  wake  up  after  sleeping, LWPs that change to the realtime
       class from some other class, LWPs that have used their full time  quan-
       tum,  and  runnable  LWPs whose priority is reset by priocntl() are all
       placed at the back of the appropriate queue for their priority. An  LWP
       that  is preempted by a higher priority LWP remains at the front of the
       queue (with whatever time is remaining in its time  quantum)  and  runs
       before  any  other  LWP  at this priority. Following a fork(2) function
       call by a realtime LWP, the parent LWP continues to run while the child
       LWP (which inherits its parent's rt_pri value) is placed at the back of
       the queue.

       A rtinfo_t structure with the following members, defined in <&lt;sys/rtpri-
       ocntl.h>&gt;,  defines the format used for the attribute data for the real-
       time class.

       short    rt_maxpri;      /* Maximum realtime priority */



       The priocntl() PC_GETCID  and  PC_GETCLINFO  commands  return  realtime
       class attributes in the pc_clinfo buffer in this format.

       The  rt_maxpri member specifies the configured maximum rt_pri value for
       the realtime class. If rt_maxpri is x, the  valid  realtime  priorities
       range from 0 to x.

       A   rtparms_t   structure   with  the  following  members,  defined  in
       <&lt;sys/rtpriocntl.h>&gt;, defines the format used  to  specify  the  realtime
       class-specific scheduling parameters of an LWP.

       short    rt_pri;       /* Real-Time priority */
       uint_t   rt_tqsecs;    /* Seconds in time quantum */
       int      rt_tqnsecs;   /* Additional nanoseconds in quantum */


       When  using  the  priocntl()  PC_SETPARMS  or  PC_GETPARMS commands, if
       pc_cid specifies the realtime class, the data in the pc_clparms  buffer
       are in this format.

       These  commands  can be used to set the realtime priority to the speci-
       fied value or get the current rt_pri value. Setting the rt_pri value of
       an  LWP that is currently running or runnable (not sleeping) causes the
       LWP to be placed at the back of the scheduling queue for the  specified
       priority.  The  LWP  is  placed  at  the  back of the appropriate queue
       regardless of whether the priority being set is different from the pre-
       vious  rt_pri  value  of the LWP. A running LWP can voluntarily release
       the CPU and go to the back of the scheduling queue at the same priority
       by  resetting  its rt_pri value to its current realtime priority value.
       To change the time quantum of an LWP without setting  the  priority  or
       affecting  the LWP's position on the queue, the rt_pri member should be
       set to the special value RT_NOCHANGE,  defined  in  <&lt;sys/rtpriocntl.h>&gt;.
       Specifying  RT_NOCHANGE  when  changing the class of an LWP to realtime
       from some other class results in the realtime priority being set to 0.

       For the priocntl() PC_GETPARMS command, if pc_cid specifies  the  real-
       time  class and more than one realtime LWP is specified, the scheduling
       parameters of the realtime LWP with the highest rt_pri value among  the
       specified  LWPs  are returned and the LWP ID of this LWP is returned by
       the priocntl() call. If there is more than one LWP sharing the  highest
       priority, the one returned is implementation-dependent.

       The  rt_tqsecs  and  rt_tqnsecs members are used for getting or setting
       the time quantum associated with an LWP or group of LWPs. rt_tqsecs  is
       the  number of seconds in the time quantum and rt_tqnsecs is the number
       of  additional  nanoseconds  in  the  quantum.  For  example,   setting
       rt_tqsecs  to 2 and rt_tqnsecs to 500,000,000 (decimal) would result in
       a time quantum of two and  one-half  seconds.  Specifying  a  value  of
       1,000,000,000  or  greater in the rt_tqnsecs member results in an error
       return with errno  set  to  EINVAL.  Although  the  resolution  of  the
       tq_nsecs  member  is  very  fine,  the specified time quantum length is
       rounded up by the system to the next integral multiple  of  the  system
       clock's  resolution.  The maximum time quantum that can be specified is
       implementation-specific and equal to INT_MAX1 ticks. The INT_MAX  value
       is  defined in <&lt;limits.h>&gt;. Requesting a quantum greater than this maxi-
       mum results in an error return with errno set to ERANGE, although infi-
       nite  quantums  can  be  requested  using  a special value as explained
       below. Requesting a time quantum of 0 by  setting  both  rt_tqsecs  and
       rt_tqnsecs to 0 results in an error return with errno set to EINVAL.

       The  rt_tqnsecs  member can also be set to one of the following special
       values defined in  <&lt;sys/rtpriocntl.h>&gt;,  in  which  case  the  value  of
       rt_tqsecs is ignored:

       RT_TQINF        Set an infinite time quantum.



       RT_TQDEF        Set  the  time quantum to the default for this priority
                       (see rt_dptbl(4)).



       RT_NOCHANGE     Do not set the time quantum. This value is useful  when
                       you  wish  to  change  the  realtime priority of an LWP
                       without affecting the  time  quantum.  Specifying  this
                       value  when  changing  the  class of an LWP to realtime
                       from some  other  class  is  equivalent  to  specifying
                       RT_TQDEF.



       When  using  the  priocntl() PC_SETXPARMS or PC_GETXPARMS commands, the
       first argument after the command code must be the  class  name  of  the
       realtime  class  ("RT") . The next arguments are formed as (key, value)
       pairs, terminated by a 0 key. The definition for the keys of the  real-
       time class can be found in <&lt;sys/rtpriocntl.h>&gt;. A repeated specification
       of the same key results in an error return and errno set to EINVAL.


       tab() allbox; lw(1.442623i)|  lw(1.081967i)|  lw(2.975410i).   KeyValue
       TypeDescription  RT_KY_PRIpri_trealtime priority RT_KY_TQSECSuint_tsec-
       onds  in  time  quantum  RT_KY_TQNSECSintnanoseconds  in  time  quantum
       RT_KY_TQSIGintrealtime time quantum signal


       When  using  the  priocntl() PC_GETXPARMS command, the value associated
       with the key is always a pointer to a scheduling parameter of the value
       type  shown  in the table above. In contrast, when using the priocntl()
       PC_SETXPARMS command, the scheduling parameter is given  as  a   direct
       value.

       A  priocntl() PC_SETXPARMS command with the class name ("RT") and with-
       out a following (key, value) pair will set or reset all realtime sched-
       uling  parameters  of  the  target process(es) to their default values.
       Changing the class of an LWP to realtime from some other  class  causes
       the  parameters to be set to their default values. The default realtime
       priority (RT_KY_PRI)  is  0.  A  default  time  quantum  (RT_TQDEF)  is
       assigned to each priority class (see rt_dptbl(4)). The default realtime
       time quantum signal (RT_KY_TQSIG) is 0.

       The value associated with RT_KY_TQSECS is the number of seconds in  the
       time  quantum. The value associated with RT_KY_TQNSECS is the number of
       nanoseconds in the quantum. Specifying  a  value  of  1,000,000,000  or
       greater  for  the  number of nanoseconds results in an error return and
       errno is set to EINVAL. The specified time quantum is rounded up by the
       system  to the next integral multiple of the system clock's resolution.
       The maximum time quantum that can be specified  is  implementation-spe-
       cific  and  equal to INT_MAX ticks, defined in <&lt;limits.h>&gt;. Requesting a
       quantum greater than this maximum results in an error return and  errno
       is  set  to  ERANGE.  If  seconds  (RT_KY_TQSECS)  but  no  nanoseconds
       (RT_KY_TQNSECS) are supplied, the number of nanoseconds is set to 0. If
       nanoseconds (RT_KY_TQNSECS) but no seconds (RT_KY_TQSECS) are supplied,
       the  number of seconds is set to 0. A time quantum of  0  (seconds  and
       nanoseconds are 0) results in an error return with errno set to EINVAL.
       Special values for RT_KY_TQSECS are RT_TQINF and RT_TQDEF (as described
       above).  The  priocntl()  command  PC_SETXPARMS  knows no special value
       RT_NOCHANGE.

       To change the class of an LWP to realtime from any other class, the LWP
       invoking priocntl() must have sufficient privileges. To change the pri-
       ority or time quantum setting of a realtime LWP, the LWP invoking  pri-
       ocntl()  must  have  sufficient privileges or must itself be a realtime
       LWP whose real or effective user ID matches the real of effective  user
       ID of the target LWP.

       The realtime priority and time quantum are inherited across fork(2) and
       the exec family of functions. When using the time quantum signal with a
       user-defined  signal  handler  across the exec functions, the new image
       must install an appropriate user-defined signal handler before the time
       quantum expires. Otherwise, unpredictable behavior might result.

TIME-SHARING CLASS
       The  time-sharing  scheduling  policy provides for a fair and effective
       allocation of the CPU resource among LWPs with varying CPU  consumption
       characteristics.  The objectives of the time-sharing policy are to pro-
       vide good response time to interactive LWPs and good throughput to CPU-
       bound  jobs,  while providing a degree of user/application control over
       scheduling.

       The time-sharing class has a range of time-sharing user  priority  (see
       ts_upri  below) values that can be assigned to LWPs within the class. A
       ts_upri value of 0 is defined as the  default  base  priority  for  the
       time-sharing class. User priorities range from -x to +x where the value
       of x is configurable and can be determined for a specific  installation
       by using the priocntl() PC_GETCID or PC_GETCLINFO command.

       The  purpose  of  the  user  priority  is  to  provide  some  degree of
       user/application control over the scheduling of LWPs in the  time-shar-
       ing class. Raising or lowering the ts_upri value of an LWP in the time-
       sharing class raises or lowers the scheduling priority of the  LWP.  It
       is  not  guaranteed,  however,  that an LWP with a higher ts_upri value
       will run before one with a lower ts_upri value, since the ts_upri value
       is just one factor used to determine the scheduling priority of a time-
       sharing LWP. The system can dynamically adjust the internal  scheduling
       priority  of  a  time-sharing LWP based on other factors such as recent
       CPU usage.

       In addition to the system-wide limits on user priority (returned by the
       PC_GETCID  and  PC_GETCLINFO commands) there is a per LWP user priority
       limit (see ts_uprilim below) specifying the maximum ts_upri value  that
       can be set for a given LWP. By default, ts_uprilim is 0.

       A tsinfo_t structure with the following members, defined in <&lt;sys/tspri-
       ocntl.h>&gt;, defines the format used for the attribute data for the  time-
       sharing class.

       short    ts_maxupri;     /* Limits of user priority range */



       The  priocntl() PC_GETCID and PC_GETCLINFO commands return time-sharing
       class attributes in the pc_clinfo buffer in this format.

       The ts_maxupri member specifies the configured  maximum  user  priority
       value  for  the time-sharing class. If ts_maxupri is x, the valid range
       for both user priorities and user priority limits is from -x to +x.

       A  tsparms_t  structure  with  the  following   members,   defined   in
       <&lt;sys/tspriocntl.h>&gt;, defines the format used to specify the time-sharing
       class-specific scheduling parameters of an LWP.

       short    ts_uprilim;     /* Time-Sharing user priority limit */
       short    ts_upri;        /* Time-Sharing user priority */



       When using the  priocntl()  PC_SETPARMS  or  PC_GETPARMS  commands,  if
       pc_cid  specifies  the  time-sharing  class, the data in the pc_clparms
       buffer is in this format.

       For the priocntl() PC_GETPARMS command, if pc_cid specifies  the  time-
       sharing  class  and  more  than  one time-sharing LWP is specified, the
       scheduling parameters of the time-sharing LWP with the highest  ts_upri
       value  among  the specified LWPs is returned and the LWP ID of this LWP
       is returned by the priocntl() call. If there is more than one LWP shar-
       ing  the  highest  user  priority,  the one returned is implementation-
       dependent.

       Any time-sharing LWP can lower its own ts_uprilim (or that  of  another
       LWP  with  the  same  user ID). Only a time-sharing LWP with sufficient
       privileges can raise a ts_uprilim. When changing the class of an LWP to
       time-sharing  from some other class, sufficient privileges are required
       to set the initial ts_uprilim to a value greater than 0. Attempts by an
       unprivileged  LWP  to  raise  a ts_uprilim or set an initial ts_uprilim
       greater than 0 fail with a return value of -1 and errno set to EPERM.

       Any time-sharing LWP can set its own ts_upri (or that  of  another  LWP
       with  the  same  user  ID) to any value less than or equal to the LWP's
       ts_uprilim. Attempts to set the ts_upri above  the  ts_uprilim  (and/or
       set  the  ts_uprilim below the ts_upri) result in the ts_upri being set
       equal to the ts_uprilim.

       Either of the ts_uprilim or ts_upri members can be set to  the  special
       value  TS_NOCHANGE,  defined  in  <&lt;sys/tspriocntl.h>&gt;, to set one of the
       values without affecting the  other.  Specifying  TS_NOCHANGE  for  the
       ts_upri  when  the ts_uprilim is being set to a value below the current
       ts_upri causes the ts_upri to be set equal to the ts_uprilim being set.
       Specifying  TS_NOCHANGE  for  a parameter when changing the class of an
       LWP to time-sharing (from some other class) causes the parameter to  be
       set  to  a default value. The default value for the ts_uprilim is 0 and
       the default for the ts_upri is to set it equal to the  ts_uprilim  that
       is being set.

       When  using  the  priocntl() PC_SETXPARMS or PC_GETXPARMS commands, the
       first argument after the command code is the class name of  the   time-
       sharing  class  ("TS")  . The next arguments are formed as (key, value)
       pairs, terminated by a 0 key. The definition for the keys of the  time-
       sharing  class can be found in  <&lt;sys/tspriocntl.h>&gt;. A repeated specifi-
       cation of the same key results in an error return and errno set to EIN-
       VAL.


       tab()  allbox;  lw(1.442623i)|  lw(1.081967i)| lw(2.975410i).  KeyValue
       TypeDescription       TS_KY_UPRILIMpri_tuser       priority       limit
       TS_KY_UPRIpri_tuser priority


       When  using  the  priocntl() PC_GETXPARMS command, the value associated
       with the key is always a pointer to a scheduling parameter of the value
       type  in  the  table  above.  In  contrast,  when  using the priocntl()
       PC_SETXPARMS command, the scheduling parameter is  given  as  a  direct
       value.

       A  priocntl() PC_SETXPARMS command with the class name ("TS") and with-
       out a following (key, value) pair will set or  reset  all  time-sharing
       scheduling  parameters  of the target process(es) to their default val-
       ues. Changing the class of an LWP to time-sharing from some other class
       causes  the  parameters  to be set to their default values. The default
       value for the user priority limit (TS_KY_UPRILIM)  is  0.  The  default
       value  for the user priority (TS_KY_UPRI) is equal to the user priority
       limit (TS_KY_UPRILIM) that is being set.

       The priocntl() command PC_SETXPARMS knows no special value TS_NOCHANGE.

       The time-sharing user priority and user priority  limit  are  inherited
       across fork() and the exec family of functions.

FAIR-SHARE CLASS
       The  fair-share  scheduling  policy  provides  a fair allocation of CPU
       resources among projects, independent of the number of  processes  they
       contain.  Projects  are  given  "shares"  to control their quota of CPU
       resources. See FSS(7) for  more  information  about  how  to  configure
       shares.

       The  fair share class supports the notion of per-LWP user priority (see
       fs_upri below) values for compatibility with the time-sharing  schedul-
       ing class. An fss_upri value of 0 is defined as the default base prior-
       ity for the fair-share class. User priorities range from -x to +x where
       the  value  of  x  is configurable and can be determined for a specific
       installation by using the priocntl() PC_GETCID or PC_GETCLINFO command.

       The purpose  of  the  user  priority  is  to  provide  some  degree  of
       user/application  control over the scheduling of LWPs in the fair-share
       class. Raising the fss_upri value of an LWP  in  the  fair-share  class
       tells the scheduler to give this LWP more CPU time slices, while lower-
       ing the fss_upri value tells the scheduler to give it less CPU  slices.
       It is not guaranteed, however, that an LWP with a higher fss_upri value
       will run before one with a lower fss_upri value. This  is  because  the
       fss_upri value is just one factor used to determine the scheduling pri-
       ority of a fair-share LWP. The system can dynamically adjust the inter-
       nal scheduling priority of a fair-share LWP based on other factors such
       as recent CPU usage. The fair-share scheduler attempts  to  provide  an
       evenly graded effect across the whole range of user priority values.

       User  priority  values  do  not interfere with project shares. That is,
       changing a user priority value of a process does not have any effect on
       its  project CPU entitlement, which is based on the number of shares it
       is allocated in comparison with other projects.

       In addition to the system-wide limits on user priority (returned by the
       PC_GETCID  and PC_GETCLINFO commands), there is a per-LWP user priority
       limit (see fs_uprilim below) that specifies the maximum fss_upri  value
       that can be set for a given LWP. By default, fss_uprilim is 0.

       A   fssinfo_t   structure   with  the  following  members,  defined  in
       <&lt;sys/fsspriocntl.h>&gt;, defines  the format used for  the  attribute  data
       for the fair-share class.

       short    fss_maxupri;    /* Limits of user priority range */


       The  priocntl()  PC_GETCID  and PC_GETCLINFO commands return fair-share
       class attributes in the pc_clinfo buffer in this format.

       fss_maxupri specifies the configured maximum user  priority  value  for
       the  fair-share  class.  If  fss_maxupri is x, the valid range for both
       user priorities and user priority limits is from -x to +x.

       A  fssparms_t  structure  with  the  following  members,   defined   in
       <&lt;sys/fsspriocntl.h>&gt;,  defines the format used to specify the fair-share
       class-specific scheduling parameters of an LWP.

       short    fss_uprilim;   /* Fair-share user priority limit */
       short    fss_upri;      /* Fair-share user priority */


       When using the  priocntl()  PC_SETPARMS  or  PC_GETPARMS  commands,  if
       pc_cid  specifies the fair-share class, the data in the pc_clparms buf-
       fer is in this format.

       For the priocntl() PC_GETPARMS command, if pc_cid specifies  the  fair-
       share class and more than one fair-share LWP is specified, the schedul-
       ing parameters of the  fair-share LWP with the  highest  fs_upri  value
       among  the  specified  LWPs  is  returned and the LWP ID of this LWP is
       returned by the priocntl() call. If there is more than one LWP  sharing
       the  highest  user  priority, the one returned is implementation-depen-
       dent.

       Any fair-share LWP can lower its own fss_uprilim (or  that  of  another
       LWP with the same user ID). Only a fair-share LWP with sufficient priv-
       ileges can raise an fss_uprilim. When changing the class of an  LWP  to
       fair-share from some other class, sufficient privileges are required to
       enter the FSS class or to  set  the  initial  fss_uprilim  to  a  value
       greater  than 0. Attempts by an unprivileged LWP to raise an fs_uprilim
       or set an initial fs_uprilim greater than 0 fail with a return value of
       -1 and errno set to EPERM.

       Any  fair-share  LWP  can  set its own fss_upri (or that of another LWP
       with the same user ID) to any value less than or  equal  to  the  LWP's
       fss_uprilim. Attempts to set the fss_upri above the fss_uprilim (and/or
       set the fss_uprilim below the fss_upri) result in  the  fss_upri  being
       set equal to the fss_uprilim.

       Either of the fss_uprilim or fss_upri members can be set to the special
       value FSS_NOCHANGE (defined in <&lt;sys/fsspriocntl.h>&gt;) to set one  of  the
       values  without  affecting  the  other. Specifying FSS_NOCHANGE for the
       fss_upri when the fss_uprilim is being set to a value below the current
       fss_upri  causes  the fss_upri to be set equal to the fss_uprilim being
       set. Specifying FSS_NOCHANGE for a parameter when changing the class of
       an LWP to fair-share (from some other class) causes the parameter to be
       set to a default value. The default value for the fss_uprilim is 0  and
       the  default  for  the  fss_upri  is to set it equal to the fss_uprilim
       which is being set.

       The fair-share user priority and  user  priority  limit  are  inherited
       across fork() and the exec family of functions.

FIXED-PRIORITY CLASS
       The  fixed-priority class provides a fixed-priority preemptive schedul-
       ing policy for those LWPs requiring that the scheduling  priorities  do
       not  get  dynamically adjusted by the system and that the user/applica-
       tion have control of the scheduling priorities.

       The fixed-priority class has a range of  fixed-priority  user  priority
       (see  fx_upri  below)  values  that  can be assigned to LWPs within the
       class. A fx_upri value of 0 is defined as the default base priority for
       the  fixed-priority  class. User priorities range from 0 to x where the
       value of x is configurable and can be determined for a specific instal-
       lation by using the priocntl() PC_GETCID or PC_GETCLINFO command.

       The purpose of the user priority is to provide user/application control
       over the scheduling of processes in the fixed-priority class. For  pro-
       cesses in the fixed-priority class, the fx_upri value is, for all prac-
       tical purposes, equivalent to the scheduling priority of  the  process.
       The  fx_upri  value  completely determines the scheduling priority of a
       fixed-priority process relative to other processes  within  its  class.
       Numerically higher fx_upri values represent higher priorities.

       In addition to the system-wide limits on user priority (returned by the
       PC_GETCID and PC_GETCLINFO commands), there is a per-LWP user  priority
       limit  (see  fx_uprilim below) that specifies the maximum fx_upri value
       that can be set for a given LWP. By default, fx_uprilim is 0.

       A structure with the following member (defined  in  <&lt;sys/fxpriocntl.h>&gt;)
       defines  the  format used for the attribute data for the fixed-priority
       class.

       pri_t   fx_maxupri;      /* Maximum user priority */


       The priocntl() PC_GETCID and PC_GETCLINFO commands return  fixed-prior-
       ity class attributes in the pc_clinfo buffer in this format.

       The  fx_maxupri  member  specifies the configured maximum user priority
       value for the fixed-priority class. If fx_maxupri is x, the valid range
       for both user priorities and user priority limits is from 0 to x.

       A  structure with the following members (defined in <&lt;sys/fxpriocntl.h>&gt;)
       defines the format used to specify  the  fixed-priority  class-specific
       scheduling parameters of an LWP.

       pri_t    fx_upri;     /* Fixed-priority user priority */
       pri_t    fx_uprilim;  /* Fixed-priority user priority limit */
       uint_t   fx_tqsecs;   /* seconds in time quantum */
       int      fx_tqnsecs;  /* additional nanosecs in time quant */


       When  using  the  priocntl()  PC_SETPARMS  or  PC_GETPARMS commands, if
       pc_cid specifies the fixed-priority class, the data in  the  pc_clparms
       buffer is in this format.

       For  the priocntl() PC_GETPARMS command, if pc_cid specifies the fixed-
       priority class and more than one fixed-priority LWP is  specified,  the
       scheduling  parameters  of  the  fixed-priority  LWP  with  the highest
       fx_upri value among the specified LWPs is returned and the  LWP  ID  of
       this  LWP is returned by the priocntl() call. If there is more than one
       LWP sharing the highest user priority, the one returned is  implementa-
       tion-dependent.

       Any fixed-priority LWP can lower its own fx_uprilim (or that of another
       LWP with the same user ID). Only a fixed-priority LWP  with  sufficient
       privileges can raise a fx_uprilim. When changing the class of an LWP to
       fixed-priority  from  some  other  class,  sufficient  privileges   are
       required  to  set  the  initial  fx_uprilim  to a value greater than 0.
       Attempts by an unprivileged LWP to raise a fx_uprilim or set an initial
       fx_uprilim  greater than 0 fail with a return value of -1 and errno set
       to EPERM.

       Any fixed-priority LWP can set its own fx_upri (or that of another  LWP
       with  the  same  user  ID) to any value less than or equal to the LWP's
       fx_uprilim. Attempts to set the fx_upri above  the  fx_uprilim  (and/or
       set  the  fx_uprilim below the fx_upri) result in the fx_upri being set
       equal to the fx_uprilim.

       Either of the fx_uprilim or fx_upri members can be set to  the  special
       value  FX_NOCHANGE  (defined  in  <&lt;sys/fxpriocntl.h>&gt;) to set one of the
       values without affecting the  other.  Specifying  FX_NOCHANGE  for  the
       fx_upri  when  the fx_uprilim is being set to a value below the current
       fx_upri causes the fx_upri to be set equal to the fx_uprilim being set.
       Specifying  FX_NOCHANGE  for  a parameter when changing the class of an
       LWP to fixed-priority (from some other class) causes the  parameter  to
       be  set  to  a default value. The default value for the fx_uprilim is 0
       and the default for the fx_upri is to set it equal  to  the  fx_uprilim
       that  is  being  set.  The default for time quantum is dependent on the
       fx_upri and on the system configuration; see fx_dptbl(4).

       The fx_tqsecs and fx_tqnsecs members are used for  getting  or  setting
       the  time quantum associated with an LWP or group of LWPs. fx_tqsecs is
       the number of seconds in the time quantum and fx_tqnsecs is the  number
       of   additional  nanoseconds  in  the  quantum.  For  example,  setting
       fx_tqsecs to 2 and fx_tqnsecs to 500,000,000 (decimal) would result  in
       a  time  quantum  of  two  and  one-half seconds. Specifying a value of
       1,000,000,000 or greater in the fx_tqnsecs member results in  an  error
       return  with  errno  set  to  EINVAL.  Although  the  resolution of the
       tq_nsecs member is very fine, the  specified  time  quantum  length  is
       rounded  up  by  the system to the next integral multiple of the system
       clock's resolution. The maximum time quantum that can be  specified  is
       implementation-specific  and  equal  to INT_MAX ticks (defined in <&lt;lim-
       its.h>&gt;). Requesting a quantum greater than this maximum results  in  an
       error  return  with errno set to ERANGE, although infinite quantums can
       be requested using a special value as  explained  below.  Requesting  a
       time  quantum of 0 (setting both fx_tqsecs and fx_tqnsecs to 0) results
       in an error return with errno set to EINVAL.

       The fx_tqnsecs member can also be set to one of the  following  special
       values  (defined  in  <&lt;sys/fxpriocntl.h>&gt;),  in  which case the value of
       fx_tqsecs is ignored:

       FX_TQINF        Set an infinite time quantum.



       FX_TQDEF        Set the time quantum to the default for  this  priority
                       (see fx_dptbl(4)).



       FX_NOCHANGE     Do  not  set  the time quantum. This value is useful in
                       changing the user priority of an LWP without  affecting
                       the  time  quantum. Specifying this value when changing
                       the class of an LWP to fixed-priority from  some  other
                       class is equivalent to specifying FX_TQDEF.



       When  using  the  priocntl() PC_SETXPARMS or PC_GETXPARMS commands, the
       first argument after the command code must be the  class  name  of  the
       fixed-priority  class  (FX)  .  The  next arguments are formed as (key,
       value) pairs, terminated by a 0 key. The definition for the keys of the
       fixed-priority  class  can  be  found in <&lt;sys/fxpriocntl.h>&gt;. A repeated
       specification of the same key results in an error return and errno  set
       to EINVAL.


       tab()  allbox;  lw(1.442623i)|  lw(1.081967i)| lw(2.975410i).  KeyValue
       TypeDescription       FX_KY_UPRILIMpri_tuser       priority       limit
       FX_KY_UPRIpri_tuser  priority FX_KY_TQSECSuint_tseconds in time quantum
       FX_KY_TQNSECSintnanoseconds in time quantum


       When using the priocntl() PC_GETXPARMS command,  the  value  associated
       with the key is always a pointer to a scheduling parameter of the value
       type shown in the table above. In contrast, when using  the  priocntl()
       PC_SETXPARMS  command,  the  scheduling  parameter is given as a direct
       value.

       A priocntl() PC_SETXPARMS command with the class name (FX) and  without
       a following (key, value) pair will set or reset all realtime scheduling
       parameters of the target process(es) to their default values.  Changing
       the  class of an LWP to fixed-priority from some other class causes the
       parameters to be set to their default values. The default value for the
       user  priority  limit  (FX_KY_UPRILIM)  is 0. The default value for the
       user  priority  (FX_KY_UPRI)  is  equal  to  the  user  priority  limit
       (FX_KY_UPRILIM) that is being set. A default time quantum (FX_TQDEF) is
       assigned to each priority class (see fx_dptbl(4)).

       The value associated with FX_KY_TQSECS is the number of seconds in  the
       time  quantum. The value associated with FX_KY_TQNSECS is the number of
       nanoseconds in the quantum. Specifying  a  value  of  1,000,000,000  or
       greater  for  the  number of nanoseconds results in an error return and
       errno is set to EINVAL. The specified time quantum is rounded up by the
       system  to the next integral multiple of the system clock's resolution.
       The maximum time quantum that can be specified  is  implementation-spe-
       cific  and  equal to INT_MAX ticks, defined in <&lt;limits.h>&gt;. Requesting a
       quantum greater than this maximum results in an error return and  errno
       is  set  to  ERANGE.  If  seconds  (FX_KY_TQSECS)  but  no  nanoseconds
       (FX_KY_TQNSECS) are supplied, the number of nanoseconds is set to 0. If
       nanoseconds (FX_KY_TQNSECS) but no seconds (FX_KY_TQSECS) are supplied,
       the number of seconds is set to 0. A time quantum  of  0  (seconds  and
       nanoseconds are 0) results in an error return with errno set to EINVAL.
       Special values for FX_KY_TQSECS are FX_TQINF and FX_TQDEF (as described
       above).  The  priocntl()  command  PC_SETXPARMS  knows no special value
       FX_NOCHANGE.

       The fixed-priority user priority and user priority limit are  inherited
       across fork(2) and the exec family of functions.

RETURN VALUES
       Unless otherwise noted above, priocntl() returns 0 on success. On fail-
       ure, priocntl() returns -1 and sets errno to indicate the error.

ERRORS
       The priocntl() function will fail if:

       EAGAIN          An attempt to change the class of an LWP failed because
                       of  insufficient resources other than memory (for exam-
                       ple, class-specific kernel data structures).



       EFAULT          One of the arguments points to an illegal address.



       EINVAL          The argument cmd was invalid, an invalid  or  unconfig-
                       ured  class  was  specified,  or  one of the parameters
                       specified was invalid.



       ENOMEM          An attempt to change the class of an LWP failed because
                       of insufficient memory.



       EPERM           The  {PRIV_PROC_PRIOCNTL}  privilege is not asserted in
                       the effective set of the calling LWP.

                       The calling LWP does not have sufficient privileges  to
                       affect the target LWP.



       ERANGE          The requested time quantum is out of range.



       ESRCH           None of the specified LWPs exist.



SEE ALSO
       priocntl(1), dispadmin(1M), init(1M), exec(2), fork(2), nice(2), prioc-
       ntlset(2), fx_dptbl(4), process(4), rt_dptbl(4), privileges(5)

       System Administration Guide: Basic Administration

       Programming Interfaces Guide



SunOS 5.10                        19 Jul 2004                      priocntl(2)