From 23ba59fbfb6ad580c4f185ffea2fa8a32b4d131d Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 27 Dec 2021 20:29:22 +0200
Subject: [PATCH] itimers: strip unused bits from struct itimer and struct
 itimers

Reviewed by:	imp, markj, mav
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D33670
---
 sys/kern/kern_time.c |  6 ------
 sys/sys/timers.h     | 29 +----------------------------
 2 files changed, 1 insertion(+), 34 deletions(-)

diff --git a/sys/kern/kern_time.c b/sys/kern/kern_time.c
index 4c53b728a500..74e7c42004ad 100644
--- a/sys/kern/kern_time.c
+++ b/sys/kern/kern_time.c
@@ -1266,13 +1266,11 @@ kern_ktimer_create(struct thread *td, clockid_t clock_id, struct sigevent *evp,
 	it = uma_zalloc(itimer_zone, M_WAITOK);
 	it->it_flags = 0;
 	it->it_usecount = 0;
-	it->it_active = 0;
 	timespecclear(&it->it_time.it_value);
 	timespecclear(&it->it_time.it_interval);
 	it->it_overrun = 0;
 	it->it_overrun_last = 0;
 	it->it_clockid = clock_id;
-	it->it_timerid = -1;
 	it->it_proc = p;
 	ksiginfo_init(&it->it_ksi);
 	it->it_ksi.ksi_flags |= KSI_INS | KSI_EXT;
@@ -1303,7 +1301,6 @@ kern_ktimer_create(struct thread *td, clockid_t clock_id, struct sigevent *evp,
 			goto out;
 		}
 	}
-	it->it_timerid = id;
 	p->p_itimers->its_timers[id] = it;
 	if (evp != NULL)
 		it->it_sigev = *evp;
@@ -1787,9 +1784,6 @@ itimers_alloc(struct proc *p)
 	struct itimers *its;
 
 	its = malloc(sizeof (struct itimers), M_SUBPROC, M_WAITOK | M_ZERO);
-	LIST_INIT(&its->its_virtual);
-	LIST_INIT(&its->its_prof);
-	TAILQ_INIT(&its->its_worklist);
 	PROC_LOCK(p);
 	if (p->p_itimers == NULL) {
 		p->p_itimers = its;
diff --git a/sys/sys/timers.h b/sys/sys/timers.h
index 5d6f0c95afa2..9e4597bca21b 100644
--- a/sys/sys/timers.h
+++ b/sys/sys/timers.h
@@ -56,47 +56,20 @@ struct itimer {
 	int	it_overrun;		/* Overruns currently accumulating */
 	int	it_overrun_last;	/* Overruns associated w/ a delivery */
 	int	it_clockid;
-	int	it_timerid;
 	ksiginfo_t	it_ksi;
-	union {
-		/* realtime */
-		struct {
-			struct callout it_callout;
-		} _rt;
-
-		/* cpu timer */
-		struct {
-			LIST_ENTRY(itimer)	it_link;
-			TAILQ_ENTRY(itimer)	it_worklink;
-			int			it_active;
-			int			it_cflags;
-		} _cpu;
-	} _data;
+	struct callout it_callout;
 };
 
-#define it_callout	_data._rt.it_callout
-#define it_link		_data._cpu.it_link
-#define it_active	_data._cpu.it_active
-#define	it_worklink	_data._cpu.it_worklink
-#define	it_cflags	_data._cpu.it_cflags
-
 #define	ITF_DELETING	0x01
 #define	ITF_WANTED	0x02
 #define	ITF_PSTOPPED	0x04
 
-#define	ITCF_ONWORKLIST	0x01
-
 #define	TIMER_MAX	32
 
 #define	ITIMER_LOCK(it)		mtx_lock(&(it)->it_mtx)
 #define	ITIMER_UNLOCK(it)	mtx_unlock(&(it)->it_mtx)
 
-LIST_HEAD(itimerlist, itimer);
-
 struct	itimers {
-	struct itimerlist	its_virtual;
-	struct itimerlist	its_prof;
-	TAILQ_HEAD(, itimer)	its_worklist;
 	struct itimer		*its_timers[TIMER_MAX];
 };