xnu-4903.270.47.tar.gz

[apple/xnu.git] / bsd / man / man2 / getpriority.2

diff --git a/bsd/man/man2/getpriority.2 b/bsd/man/man2/getpriority.2
index 07ed5b6d81d8fa3e77fc79251677e68ab37a54cd..71140276c58462387738b014ea3523c2a860921f 100644 (file)
--- a/bsd/man/man2/getpriority.2
+++ b/bsd/man/man2/getpriority.2
@@ -54,8 +54,7 @@
 .Fa "int prio"
 .Fc
 .Sh DESCRIPTION
 .Fa "int prio"
 .Fc
 .Sh DESCRIPTION

-The scheduling
-priority of the process, process group, or user as indicated by
+The scheduling priority of the process, process group, or user as indicated by

 .Fa which
 and
 .Fa who
 .Fa which
 and
 .Fa who


@@ -63,15 +62,13 @@ is obtained with the
 .Fn getpriority
 call and set with the
 .Fn setpriority
 .Fn getpriority
 call and set with the
 .Fn setpriority

-call.  Additionally, the current thread can be set to background
-state.
+call.

 .Fa Which
 is one of
 .Dv PRIO_PROCESS ,
 .Dv PRIO_PGRP ,
 .Fa Which
 is one of
 .Dv PRIO_PROCESS ,
 .Dv PRIO_PGRP ,

-.Dv PRIO_USER ,

 or
 or

-.Dv PRIO_DARWIN_THREAD ,
+.Dv PRIO_USER ,

 and 
 .Fa who
 is interpreted relative to 
 and 
 .Fa who
 is interpreted relative to 


@@ -85,30 +82,39 @@ and a user ID for
 .Dv PRIO_USER ) .
 A zero value of
 .Fa who
 .Dv PRIO_USER ) .
 A zero value of
 .Fa who

-denotes the current process, process group, user, thread (for PRIO_DARWIN_THREAD).
+denotes the current process, process group, or user.

 .Fa prio
 is a value in the range -20 to 20.  The default priority is 0;
 lower priorities cause more favorable scheduling.
 .Fa prio
 is a value in the range -20 to 20.  The default priority is 0;
 lower priorities cause more favorable scheduling.

-For PRIO_DARWIN_THREAD,
-.Fa prio
-is either 0 (to remove current thread from background status) or PRIO_DARWIN_BG
-(to set current thread into background state).

 .Pp
 The
 .Fn getpriority
 call returns the highest priority (lowest numerical value)
 .Pp
 The
 .Fn getpriority
 call returns the highest priority (lowest numerical value)

-enjoyed by any of the specified processes or for PRIO_DARWIN_THREAD
-returns 0 when current thread is not in background state or 1
-when the current thread is in background state.
+enjoyed by any of the specified processes.

 The
 .Fn setpriority
 call sets the priorities of all of the specified processes
 The
 .Fn setpriority
 call sets the priorities of all of the specified processes

-to the specified value.  When setting a thread into background
-state the scheduling priority is set to lowest value, disk and
-network IO are throttled.  Network IO will be throttled for any
-sockets the thread opens after going into background state.  Any
-previously opened sockets are not affected.
-Only the super-user may lower priorities, but any thread can set
+to the specified value.  Only the super-user may lower priorities.
+.Pp
+Additionally, the current thread or process can be placed in a background state
+by specifying PRIO_DARWIN_THREAD or PRIO_DARWIN_PROCESS for
+.Fa which .
+Only a value of zero (the current thread or process) is supported for
+.Fa who
+when setting or getting background state.
+.Fa prio
+is either 0 (to remove current thread from background status) or PRIO_DARWIN_BG
+(to set current thread into background state).
+When a thread or process is in a background state the scheduling priority is set
+to the lowest value, disk IO is throttled (with behavior similar to using
+.Xr setiopolicy_np 3
+to set a throttleable policy), and network IO is throttled for
+any sockets opened after going into background state.  Any previously opened
+sockets are not affected.
+The
+.Fn getpriority
+call returns 0 when current thread or process is not in background state or 1
+when the current thread is in background state.  Any thread or process can set

 itself into background state.
 .Sh RETURN VALUES
 Since
 itself into background state.
 .Sh RETURN VALUES
 Since


@@ -124,7 +130,7 @@ The
 call returns 0 if there is no error, or
 -1 if there is.
 .Sh ERRORS
 call returns 0 if there is no error, or
 -1 if there is.
 .Sh ERRORS

-.Fn Getpriority
+.Fn getpriority

 and
 .Fn setpriority
 will fail if:
 and
 .Fn setpriority
 will fail if:


@@ -136,8 +142,9 @@ is not one of
 .Dv PRIO_PROCESS ,
 .Dv PRIO_PGRP ,
 .Dv PRIO_USER ,
 .Dv PRIO_PROCESS ,
 .Dv PRIO_PGRP ,
 .Dv PRIO_USER ,

+.Dv PRIO_DARWIN_THREAD ,

 or
 or

-.Dv PRIO_DARWIN_THREAD .
+.Dv PRIO_DARWIN_PROCESS .

 .\" ==========
 .It Bq Er EINVAL
 .Fa Who
 .\" ==========
 .It Bq Er EINVAL
 .Fa Who


@@ -147,7 +154,10 @@ is not a valid process, process group, or user ID.
 .Fa Who
 is not 0 when
 .Fa which
 .Fa Who
 is not 0 when
 .Fa which

-is PRIO_DARWIN_THREAD.
+is 
+.Dv PRIO_DARWIN_THREAD
+or
+.Dv PRIO_DARWIN_PROCESS .

 .\" ==========
 .It Bq Er ESRCH
 No process can be located using the 
 .\" ==========
 .It Bq Er ESRCH
 No process can be located using the 


@@ -199,6 +209,7 @@ has changed.
 .Sh SEE ALSO
 .Xr nice 1 ,
 .Xr fork 2 ,
 .Sh SEE ALSO
 .Xr nice 1 ,
 .Xr fork 2 ,

+.Xr setiopolicy_np 3 ,

 .Xr compat 5 ,
 .Xr renice 8
 .Sh HISTORY
 .Xr compat 5 ,
 .Xr renice 8
 .Sh HISTORY