diff --git a/ObsoleteFiles.inc b/ObsoleteFiles.inc
--- a/ObsoleteFiles.inc
+++ b/ObsoleteFiles.inc
@@ -52,6 +52,15 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 20221015: update the ithread(9) man page
+OLD_FILES+=usr/share/man/man9/ithread.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_add_handler.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_create.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_destroy.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_priority.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_remove_handler.9.gz
+OLD_FILES+=usr/share/man/man9/ithread_schedule.9.gz
+
 # 20221012: remove nls support from sort
 OLD_FILES+=usr/share/nls/hu_HU.ISO8859-2/sort.cat
 
diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -190,8 +190,8 @@
 	ifnet.9 \
 	inittodr.9 \
 	insmntque.9 \
+	intr_event.9 \
 	intro.9 \
-	ithread.9 \
 	kasan.9 \
 	KASSERT.9 \
 	kern_reboot.9 \
@@ -1319,12 +1319,11 @@
 	ifnet.9 ifunit.9 \
 	ifnet.9 ifunit_ref.9
 MLINKS+=insmntque.9 insmntque1.9
-MLINKS+=ithread.9 ithread_add_handler.9 \
-	ithread.9 ithread_create.9 \
-	ithread.9 ithread_destroy.9 \
-	ithread.9 ithread_priority.9 \
-	ithread.9 ithread_remove_handler.9 \
-	ithread.9 ithread_schedule.9
+MLINKS+=intr_event.9 intr_event_add_handler.9 \
+	intr_event.9 intr_event_create.9 \
+	intr_event.9 intr_event_destroy.9 \
+	intr_event.9 intr_event_remove_handler.9 \
+	intr_event.9 intr_priority.9
 MLINKS+=kernacc.9 useracc.9
 MLINKS+=kernel_mount.9 free_mntarg.9 \
 	kernel_mount.9 mount_arg.9 \
diff --git a/share/man/man9/ithread.9 b/share/man/man9/intr_event.9
rename from share/man/man9/ithread.9
rename to share/man/man9/intr_event.9
--- a/share/man/man9/ithread.9
+++ b/share/man/man9/intr_event.9
@@ -23,25 +23,25 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd August 25, 2006
-.Dt ITHREAD 9
+.Dd October 15, 2022
+.Dt INTR_EVENT 9
 .Os
 .Sh NAME
-.Nm ithread_add_handler ,
-.Nm ithread_create ,
-.Nm ithread_destroy ,
-.Nm ithread_priority ,
-.Nm ithread_remove_handler ,
-.Nm ithread_schedule
-.Nd kernel interrupt threads
+.Nm intr_event_add_handler ,
+.Nm intr_event_create ,
+.Nm intr_event_destroy ,
+.Nm intr_event_remove_handler ,
+.Nm intr_priority
+.Nd "kernel interrupt handler and thread API"
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/bus.h
 .In sys/interrupt.h
 .Ft int
-.Fo ithread_add_handler
-.Fa "struct ithd *ithread"
+.Fo intr_event_add_handler
+.Fa "struct intr_event *ie"
 .Fa "const char *name"
+.Fa "driver_filter_t filter"
 .Fa "driver_intr_t handler"
 .Fa "void *arg"
 .Fa "u_char pri"
@@ -49,23 +49,24 @@
 .Fa "void **cookiep"
 .Fc
 .Ft int
-.Fo ithread_create
-.Fa "struct ithd **ithread"
-.Fa "int vector"
+.Fo intr_event_create
+.Fa "struct intr_event **event"
+.Fa "void *source"
 .Fa "int flags"
-.Fa "void (*disable)(int)"
-.Fa "void (*enable)(int)"
+.Fa "int irq"
+.Fa "void (*pre_ithread)(void *)"
+.Fa "void (*post_ithread)(void *)"
+.Fa "void (*post_filter)(void *)"
+.Fa "int (*assign_cpu)(void *, int)"
 .Fa "const char *fmt"
 .Fa "..."
 .Fc
 .Ft int
-.Fn ithread_destroy "struct ithd *ithread"
-.Ft u_char
-.Fn ithread_priority "enum intr_type flags"
-.Ft int
-.Fn ithread_remove_handler "void *cookie"
+.Fn intr_event_destroy "struct intr_event *ie"
 .Ft int
-.Fn ithread_schedule "struct ithd *ithread" "int do_switch"
+.Fn intr_event_remove_handler "void *cookie"
+.Ft u_char
+.Fn intr_priority "enum intr_type flags"
 .Sh DESCRIPTION
 Interrupt threads are kernel threads that run a list of handlers when
 triggered by either a hardware or software interrupt.
@@ -82,23 +83,20 @@
 represented as a vector number.
 .Pp
 The
-.Fn ithread_create
+.Fn intr_event_create
 function creates a new interrupt thread.
 The
-.Fa ithread
-argument points to an
-.Vt struct ithd
+.Fa source
+argument points to a
+.Vt struct intr_event event
 pointer that will point to the newly created thread upon success.
 The
-.Fa vector
-argument specifies the interrupt source to associate this thread with.
-The
 .Fa flags
 argument is a mask of properties of this thread.
 The only valid flag currently for
-.Fn ithread_create
+.Fn intr_event_create
 is
-.Dv IT_SOFT
+.Dv IE_SOFT
 to specify that this interrupt thread is a software interrupt.
 The
 .Fa enable
@@ -110,18 +108,18 @@
 source as their only argument.
 The remaining arguments form a
 .Xr printf 9
-argument list that is used to build the base name of the new ithread.
+argument list that is used to build the base name of the new interrupt thread.
 The full name of an interrupt thread is formed by concatenating the base
-name of an interrupt thread with the names of all of its interrupt handlers.
+name of the interrupt thread with the names of all of its interrupt handlers.
 .Pp
 The
-.Fn ithread_destroy
+.Fn intr_event_destroy
 function destroys a previously created interrupt thread by releasing its
 resources and arranging for the backing kernel thread to terminate.
 An interrupt thread can only be destroyed if it has no handlers remaining.
 .Pp
 The
-.Fn ithread_add_handler
+.Fn intr_event_add_handler
 function adds a new handler to an existing interrupt thread specified by
 .Fa ithread .
 The
@@ -150,25 +148,17 @@
 handler.
 .Pp
 The
-.Fn ithread_remove_handler
+.Fn intr_event_remove_handler
 removes a handler from an interrupt thread.
 The
 .Fa cookie
 argument specifies the handler to remove from its thread.
 .Pp
 The
-.Fn ithread_schedule
-function schedules an interrupt thread to run.
-If the
-.Fa do_switch
-argument is non-zero and the interrupt thread is idle, then a context switch
-will be forced after putting the interrupt thread on the run queue.
-.Pp
-The
-.Fn ithread_priority
+.Fn intr_priority
 function translates the
 .Dv INTR_TYPE_*
-interrupt flags into interrupt handler priorities.
+interrupt flags into interrupt thread scheduling priorities.
 .Pp
 The interrupt flags not related to the type of a particular interrupt
 .Pq Dv INTR_TYPE_*
@@ -198,24 +188,23 @@
 Any allocation errors must be handled thereafter.
 .Sh RETURN VALUES
 The
-.Fn ithread_add_handler ,
-.Fn ithread_create ,
-.Fn ithread_destroy ,
-.Fn ithread_remove_handler ,
+.Fn intr_event_add_handler ,
+.Fn intr_event_create ,
+.Fn intr_event_destroy ,
 and
-.Fn ithread_schedule
+.Fn intr_event_remove_handler
 functions return zero on success and non-zero on failure.
 The
-.Fn ithread_priority
+.Fn intr_priority
 function returns a process priority corresponding to the passed in interrupt
 flags.
 .Sh EXAMPLES
 The
 .Fn swi_add
 function demonstrates the use of
-.Fn ithread_create
+.Fn intr_event_create
 and
-.Fn ithread_add_handler .
+.Fn intr_event_add_handler .
 .Bd -literal -offset indent
 int
 swi_add(struct ithd **ithdp, const char *name, driver_intr_t handler,
@@ -248,67 +237,63 @@
 .Ed
 .Sh ERRORS
 The
-.Fn ithread_add_handler
+.Fn intr_event_add_handler
 function will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
-Any of the
-.Fa ithread ,
-.Fa handler ,
+The
+.Fa ie
 or
 .Fa name
 arguments are
 .Dv NULL .
 .It Bq Er EINVAL
 The
-.Dv INTR_EXCL
+.Fa handler
+and
+.Fa filter
+arguments are both
+.Dv NULL .
+.It Bq Er EINVAL
+The
+.Dv IH_EXCLUSIVE
 flag is specified and the interrupt thread
-.Fa ithread
+.Fa ie
 already has at least one handler, or the interrupt thread
-.Fa ithread
+.Fa ie
 already has an exclusive handler.
-.It Bq Er ENOMEM
-Could not allocate needed memory for this handler.
 .El
 .Pp
 The
-.Fn ithread_create
+.Fn intr_event_create
 function will fail if:
 .Bl -tag -width Er
-.It Bq Er EAGAIN
-The system-imposed limit on the total
-number of processes under execution would be exceeded.
-The limit is given by the
-.Xr sysctl 3
-MIB variable
-.Dv KERN_MAXPROC .
 .It Bq Er EINVAL
 A flag other than
-.Dv IT_SOFT
+.Dv IE_SOFT
 was specified in the
 .Fa flags
 parameter.
-.It Bq Er ENOMEM
-Could not allocate needed memory for this interrupt thread.
 .El
 .Pp
 The
-.Fn ithread_destroy
+.Fn intr_event_destroy
 function will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
 The
-.Fa ithread
+.Fa ie
 argument is
 .Dv NULL .
-.It Bq Er EINVAL
-The interrupt thread pointed to by
-.Fa ithread
-has at least one handler.
+.It Bq Er EBUSY
+The interrupt event pointed to by
+.Fa ie
+has at least one handler which has not been removed with
+.Fn intr_event_remove_handler .
 .El
 .Pp
 The
-.Fn ithread_remove_handler
+.Fn intr_event_remove_handler
 function will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
@@ -317,21 +302,6 @@
 argument is
 .Dv NULL .
 .El
-.Pp
-The
-.Fn ithread_schedule
-function will fail if:
-.Bl -tag -width Er
-.It Bq Er EINVAL
-The
-.Fa ithread
-argument is
-.Dv NULL .
-.It Bq Er EINVAL
-The interrupt thread pointed to by
-.Fa ithread
-has no interrupt handlers.
-.El
 .Sh SEE ALSO
 .Xr kthread 9 ,
 .Xr malloc 9 ,
@@ -340,11 +310,3 @@
 .Sh HISTORY
 Interrupt threads and their corresponding API first appeared in
 .Fx 5.0 .
-.Sh BUGS
-Currently
-.Vt struct ithd
-represents both an interrupt source and an interrupt thread.
-There should be a separate
-.Vt struct isrc
-that contains a vector number, enable and disable functions, etc.\& that
-an ithread holds a reference to.
diff --git a/share/man/man9/socket.9 b/share/man/man9/socket.9
--- a/share/man/man9/socket.9
+++ b/share/man/man9/socket.9
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 18, 2018
+.Dd September 6, 2022
 .Dt SOCKET 9
 .Os
 .Sh NAME
@@ -171,8 +171,7 @@
 .Pp
 Except where otherwise indicated,
 .Nm
-functions may sleep, and are not appropriate for use in an
-.Xr ithread 9
+functions may sleep, and are not appropriate for use in an interrupt thread
 context or while holding non-sleepable kernel locks.
 .Ss Creating and Destroying Sockets
 A new socket may be created using
@@ -461,10 +460,8 @@
 .Xr sendmsg 2
 system call.
 .Pp
-Kernel callers running in
-.Xr ithread 9
-context, or with a mutex held, will wish to use non-blocking sockets and pass
-the
+Kernel callers running in an interrupt thread context, or with a mutex held,
+will wish to use non-blocking sockets and pass the
 .Dv MSG_DONTWAIT
 flag in order to prevent these functions from sleeping.
 .Pp
@@ -593,7 +590,7 @@
 .Xr shutdown 2 ,
 .Xr socket 2 ,
 .Xr ng_ksocket 4 ,
-.Xr ithread 9 ,
+.Xr intr_event 9 ,
 .Xr msleep 9 ,
 .Xr ucred 9
 .Sh HISTORY
diff --git a/share/man/man9/swi.9 b/share/man/man9/swi.9
--- a/share/man/man9/swi.9
+++ b/share/man/man9/swi.9
@@ -208,7 +208,7 @@
 .El
 .Sh SEE ALSO
 .Xr hardclock 9 ,
-.Xr ithread 9 ,
+.Xr intr_event 9 ,
 .Xr taskqueue 9
 .Sh HISTORY
 The