sched_setparam.2: Clarify that scheduling parameters are per-thread (not per-process)

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/sched_setparam.2

@@ -47,12 +47,12 @@ sched_setparam, sched_getparam \- set and get scheduling parameters
 .SH DESCRIPTION
 .BR sched_setparam ()
 sets the scheduling parameters associated with the scheduling policy
-for the process identified by \fIpid\fP.
+for the thread whose thread ID is specified in \fIpid\fP.
 If \fIpid\fP is zero, then
-the parameters of the calling process are set.
+the parameters of the calling thread are set.
 The interpretation of
 the argument \fIparam\fP depends on the scheduling
-policy of the process identified by
+policy of the thread identified by
 .IR pid .
 See
 .BR sched (7)
@@ -60,9 +60,9 @@ for a description of the scheduling policies supported under Linux.
 .PP
 .BR sched_getparam ()
 retrieves the scheduling parameters for the
-process identified by \fIpid\fP.
+thread identified by \fIpid\fP.
 If \fIpid\fP is zero, then the parameters
-of the calling process are retrieved.
+of the calling thread are retrieved.
 .PP
 .BR sched_setparam ()
 checks the validity of \fIparam\fP for the scheduling policy of the
@@ -109,24 +109,19 @@ scheduling policy.
 .TP
 .B EPERM
 .RB ( sched_setparam ())
-The calling process does not have appropriate privileges
+The caller does not have appropriate privileges
 (Linux: does not have the
 .B CAP_SYS_NICE
 capability).
 .TP
 .B ESRCH
-The process whose ID is \fIpid\fP could not be found.
+The thread whose ID is \fIpid\fP could not be found.
 .SH CONFORMING TO
 POSIX.1-2001, POSIX.1-2008.
-.SH NOTES
-.PP
-Scheduling parameters are in fact per-thread
-attributes on Linux;
-see
-.BR sched (7).
 .SH SEE ALSO
 .ad l
 .nh
+.BR gettid (2),
 .BR getpriority (2),
 .BR nice (2),
 .BR sched_get_priority_max (2),