Index: sys/amd64/amd64/pmap.c
===================================================================
--- sys/amd64/amd64/pmap.c
+++ sys/amd64/amd64/pmap.c
@@ -3935,7 +3935,6 @@
 	pd_entry_t newpde;
 	pt_entry_t *firstpte, oldpte, pa, *pte;
 	pt_entry_t PG_G, PG_A, PG_M, PG_RW, PG_V;
-	vm_offset_t oldpteva;
 	vm_page_t mpte;
 	int PG_PTE_CACHE;
 
@@ -3995,10 +3994,9 @@
 			if (!atomic_cmpset_long(pte, oldpte, oldpte & ~PG_RW))
 				goto setpte;
 			oldpte &= ~PG_RW;
-			oldpteva = (oldpte & PG_FRAME & PDRMASK) |
-			    (va & ~PDRMASK);
 			CTR2(KTR_PMAP, "pmap_promote_pde: protect for va %#lx"
-			    " in pmap %p", oldpteva, pmap);
+			    " in pmap %p", (oldpte & PG_FRAME & PDRMASK) |
+			    (va & ~PDRMASK), pmap);
 		}
 		if ((oldpte & PG_PTE_PROMOTE) != (newpde & PG_PTE_PROMOTE)) {
 			atomic_add_long(&pmap_pde_p_failures, 1);
Index: sys/amd64/amd64/vm_machdep.c
===================================================================
--- sys/amd64/amd64/vm_machdep.c
+++ sys/amd64/amd64/vm_machdep.c
@@ -155,7 +155,6 @@
 	struct pcb *pcb2;
 	struct mdproc *mdp1, *mdp2;
 	struct proc_ldt *pldt;
-	pmap_t pmap2;
 
 	p1 = td1->td_proc;
 	if ((flags & RFPROC) == 0) {
@@ -218,7 +217,6 @@
 	 * Set registers for trampoline to user mode.  Leave space for the
 	 * return address on stack.  These are the kernel mode register values.
 	 */
-	pmap2 = vmspace_pmap(p2->p_vmspace);
 	pcb2->pcb_r12 = (register_t)fork_return;	/* fork_trampoline argument */
 	pcb2->pcb_rbp = 0;
 	pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
Index: sys/amd64/ia32/ia32_reg.c
===================================================================
--- sys/amd64/ia32/ia32_reg.c
+++ sys/amd64/ia32/ia32_reg.c
@@ -79,11 +79,9 @@
 int
 fill_regs32(struct thread *td, struct reg32 *regs)
 {
-	struct pcb *pcb;
 	struct trapframe *tp;
 
 	tp = td->td_frame;
-	pcb = td->td_pcb;
 	if (tp->tf_flags & TF_HASSEGS) {
 		regs->r_gs = tp->tf_gs;
 		regs->r_fs = tp->tf_fs;
@@ -113,18 +111,16 @@
 int
 set_regs32(struct thread *td, struct reg32 *regs)
 {
-	struct pcb *pcb;
 	struct trapframe *tp;
 
 	tp = td->td_frame;
 	if (!EFL_SECURE(regs->r_eflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
 		return (EINVAL);
-	pcb = td->td_pcb;
 	tp->tf_gs = regs->r_gs;
 	tp->tf_fs = regs->r_fs;
 	tp->tf_es = regs->r_es;
 	tp->tf_ds = regs->r_ds;
-	set_pcb_flags(pcb, PCB_FULL_IRET);
+	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
 	tp->tf_flags = TF_HASSEGS;
 	tp->tf_rdi = regs->r_edi;
 	tp->tf_rsi = regs->r_esi;
Index: sys/dev/pci/pci.c
===================================================================
--- sys/dev/pci/pci.c
+++ sys/dev/pci/pci.c
@@ -2389,7 +2389,7 @@
 	struct pci_devinfo *dinfo = device_get_ivars(child);
 	pcicfgregs *cfg = &dinfo->cfg;
 	uint16_t status;
-	int result, oldstate, highest, delay;
+	int oldstate, highest, delay;
 
 	if (cfg->pp.pp_cap == 0)
 		return (EOPNOTSUPP);
@@ -2424,7 +2424,6 @@
 	    delay = 0;
 	status = PCI_READ_CONFIG(dev, child, cfg->pp.pp_status, 2)
 	    & ~PCIM_PSTAT_DMASK;
-	result = 0;
 	switch (state) {
 	case PCI_POWERSTATE_D0:
 		status |= PCIM_PSTAT_D0;
@@ -2989,7 +2988,6 @@
 pci_ata_maps(device_t bus, device_t dev, struct resource_list *rl, int force,
     uint32_t prefetchmask)
 {
-	struct resource *r;
 	int rid, type, progif;
 #if 0
 	/* if this device supports PCI native addressing use it */
@@ -3012,11 +3010,11 @@
 	} else {
 		rid = PCIR_BAR(0);
 		resource_list_add(rl, type, rid, 0x1f0, 0x1f7, 8);
-		r = resource_list_reserve(rl, bus, dev, type, &rid, 0x1f0,
+		(void)resource_list_reserve(rl, bus, dev, type, &rid, 0x1f0,
 		    0x1f7, 8, 0);
 		rid = PCIR_BAR(1);
 		resource_list_add(rl, type, rid, 0x3f6, 0x3f6, 1);
-		r = resource_list_reserve(rl, bus, dev, type, &rid, 0x3f6,
+		(void)resource_list_reserve(rl, bus, dev, type, &rid, 0x3f6,
 		    0x3f6, 1, 0);
 	}
 	if (progif & PCIP_STORAGE_IDE_MODESEC) {
@@ -3027,11 +3025,11 @@
 	} else {
 		rid = PCIR_BAR(2);
 		resource_list_add(rl, type, rid, 0x170, 0x177, 8);
-		r = resource_list_reserve(rl, bus, dev, type, &rid, 0x170,
+		(void)resource_list_reserve(rl, bus, dev, type, &rid, 0x170,
 		    0x177, 8, 0);
 		rid = PCIR_BAR(3);
 		resource_list_add(rl, type, rid, 0x376, 0x376, 1);
-		r = resource_list_reserve(rl, bus, dev, type, &rid, 0x376,
+		(void)resource_list_reserve(rl, bus, dev, type, &rid, 0x376,
 		    0x376, 1, 0);
 	}
 	pci_add_map(bus, dev, PCIR_BAR(4), rl, force,
@@ -3727,7 +3725,6 @@
 static void
 pci_set_power_child(device_t dev, device_t child, int state)
 {
-	struct pci_devinfo *dinfo;
 	device_t pcib;
 	int dstate;
 
@@ -3739,7 +3736,6 @@
 	 * are handled separately.
 	 */
 	pcib = device_get_parent(dev);
-	dinfo = device_get_ivars(child);
 	dstate = state;
 	if (device_is_attached(child) &&
 	    PCIB_POWER_FOR_SLEEP(pcib, child, &dstate) == 0)
Index: sys/kern/kern_exit.c
===================================================================
--- sys/kern/kern_exit.c
+++ sys/kern/kern_exit.c
@@ -964,12 +964,10 @@
     int *status, int options, struct __wrusage *wrusage, siginfo_t *siginfo,
     int check_only)
 {
-	struct proc *q;
 	struct rusage *rup;
 
 	sx_assert(&proctree_lock, SA_XLOCKED);
 
-	q = td->td_proc;
 	PROC_LOCK(p);
 
 	switch (idtype) {
Index: sys/kern/kern_synch.c
===================================================================
--- sys/kern/kern_synch.c
+++ sys/kern/kern_synch.c
@@ -414,11 +414,9 @@
 {
 	uint64_t runtime, new_switchtime;
 	struct thread *td;
-	struct proc *p;
 
 	td = curthread;			/* XXX */
 	THREAD_LOCK_ASSERT(td, MA_OWNED | MA_NOTRECURSED);
-	p = td->td_proc;		/* XXX */
 	KASSERT(!TD_ON_RUNQ(td), ("mi_switch: called by old code"));
 #ifdef INVARIANTS
 	if (!TD_ON_LOCK(td) && !TD_IS_RUNNING(td))
@@ -458,7 +456,7 @@
 	PCPU_INC(cnt.v_swtch);
 	PCPU_SET(switchticks, ticks);
 	CTR4(KTR_PROC, "mi_switch: old thread %ld (td_sched %p, pid %ld, %s)",
-	    td->td_tid, td->td_sched, p->p_pid, td->td_name);
+	    td->td_tid, td->td_sched, td->td_proc->p_pid, td->td_name);
 #if (KTR_COMPILE & KTR_SCHED) != 0
 	if (TD_IS_IDLETHREAD(td))
 		KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "idle",
@@ -474,7 +472,7 @@
 	    "prio:%d", td->td_priority);
 
 	CTR4(KTR_PROC, "mi_switch: new thread %ld (td_sched %p, pid %ld, %s)",
-	    td->td_tid, td->td_sched, p->p_pid, td->td_name);
+	    td->td_tid, td->td_sched, td->td_proc->p_pid, td->td_name);
 
 	/* 
 	 * If the last thread was exiting, finish cleaning it up.
Index: sys/kern/vfs_cluster.c
===================================================================
--- sys/kern/vfs_cluster.c
+++ sys/kern/vfs_cluster.c
@@ -310,7 +310,6 @@
 cluster_rbuild(struct vnode *vp, u_quad_t filesize, daddr_t lbn,
     daddr_t blkno, long size, int run, int gbflags, struct buf *fbp)
 {
-	struct bufobj *bo;
 	struct buf *bp, *tbp;
 	daddr_t bn;
 	off_t off;
@@ -376,7 +375,6 @@
 	bp->b_npages = 0;
 
 	inc = btodb(size);
-	bo = &vp->v_bufobj;
 	for (bn = blkno, i = 0; i < run; ++i, bn += inc) {
 		if (i == 0) {
 			VM_OBJECT_WLOCK(tbp->b_bufobj->bo_object);
Index: sys/kern/vfs_init.c
===================================================================
--- sys/kern/vfs_init.c
+++ sys/kern/vfs_init.c
@@ -311,9 +311,7 @@
 vfs_unregister(struct vfsconf *vfc)
 {
 	struct vfsconf *vfsp;
-	int error, i, maxtypenum;
-
-	i = vfc->vfc_typenum;
+	int error, maxtypenum;
 
 	vfsconf_lock();
 	vfsp = vfs_byname_locked(vfc->vfc_name);
Index: sys/ufs/ffs/ffs_softdep.c
===================================================================
--- sys/ufs/ffs/ffs_softdep.c
+++ sys/ufs/ffs/ffs_softdep.c
@@ -4691,12 +4691,10 @@
 	struct inodedep *inodedep;
 	struct jaddref *jaddref;
 	struct vnode *dvp;
-	struct vnode *vp;
 
 	KASSERT(MOUNTEDSOFTDEP(UFSTOVFS(dp->i_ump)) != 0,
 	    ("softdep_setup_dotdot_link called on non-softdep filesystem"));
 	dvp = ITOV(dp);
-	vp = ITOV(ip);
 	jaddref = NULL;
 	/*
 	 * We don't set MKDIR_PARENT as this is not tied to a mkdir and
@@ -7052,7 +7050,6 @@
 	struct bufobj *bo;
 	struct vnode *vp;
 	struct buf *bp;
-	struct fs *fs;
 	int blkoff;
 
 	/*
@@ -7061,7 +7058,6 @@
 	 * Once they are all there, walk the list and get rid of
 	 * any dependencies.
 	 */
-	fs = ip->i_fs;
 	vp = ITOV(ip);
 	bo = &vp->v_bufobj;
 	BO_LOCK(bo);
@@ -9493,12 +9489,10 @@
 	struct buf *bp;
 {
 	struct inodedep *inodedep;
-	struct mount *mp;
 	struct fs *fs;
 
 	LOCK_OWNED(sbdep->sb_ump);
 	fs = sbdep->sb_fs;
-	mp = UFSTOVFS(sbdep->sb_ump);
 	/*
 	 * If the superblock doesn't match the in-memory list start over.
 	 */
Index: sys/ufs/ffs/ffs_suspend.c
===================================================================
--- sys/ufs/ffs/ffs_suspend.c
+++ sys/ufs/ffs/ffs_suspend.c
@@ -177,7 +177,6 @@
 static int
 ffs_susp_suspend(struct mount *mp)
 {
-	struct fs *fs;
 	struct ufsmount *ump;
 	int error;
 
@@ -189,7 +188,6 @@
 		return (EBUSY);
 
 	ump = VFSTOUFS(mp);
-	fs = ump->um_fs;
 
 	/*
 	 * Make sure the calling thread is permitted to access the mounted
Index: sys/ufs/ffs/ffs_vfsops.c
===================================================================
--- sys/ufs/ffs/ffs_vfsops.c
+++ sys/ufs/ffs/ffs_vfsops.c
@@ -1486,7 +1486,7 @@
 	struct inode *ip;
 	struct ufsmount *ump = VFSTOUFS(mp);
 	struct fs *fs;
-	int error, count, wait, lockreq, allerror = 0;
+	int error, count, lockreq, allerror = 0;
 	int suspend;
 	int suspended;
 	int secondary_writes;
@@ -1495,7 +1495,6 @@
 	int softdep_accdeps;
 	struct bufobj *bo;
 
-	wait = 0;
 	suspend = 0;
 	suspended = 0;
 	td = curthread;
@@ -1517,10 +1516,8 @@
 		suspend = 1;
 		waitfor = MNT_WAIT;
 	}
-	if (waitfor == MNT_WAIT) {
-		wait = 1;
+	if (waitfor == MNT_WAIT)
 		lockreq = LK_EXCLUSIVE;
-	}
 	lockreq |= LK_INTERLOCK | LK_SLEEPFAIL;
 loop:
 	/* Grab snapshot of secondary write counts */
@@ -2024,7 +2021,6 @@
 ffs_bufwrite(struct buf *bp)
 {
 	struct buf *newbp;
-	int oldflags;
 
 	CTR3(KTR_BUF, "bufwrite(%p) vp %p flags %X", bp, bp->b_vp, bp->b_flags);
 	if (bp->b_flags & B_INVAL) {
@@ -2032,8 +2028,6 @@
 		return (0);
 	}
 
-	oldflags = bp->b_flags;
-
 	if (!BUF_ISLOCKED(bp))
 		panic("bufwrite: buffer is not busy???");
 	/*
Index: sys/ufs/ffs/ffs_vnops.c
===================================================================
--- sys/ufs/ffs/ffs_vnops.c
+++ sys/ufs/ffs/ffs_vnops.c
@@ -1366,11 +1366,6 @@
 };
 */
 {
-	struct inode *ip;
-	struct fs *fs;
-
-	ip = VTOI(ap->a_vp);
-	fs = ip->i_fs;
 
 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
 		return (EOPNOTSUPP);
@@ -1394,11 +1389,6 @@
 };
 */
 {
-	struct inode *ip;
-	struct fs *fs;
-
-	ip = VTOI(ap->a_vp);
-	fs = ip->i_fs;
 
 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
 		return (EOPNOTSUPP);
@@ -1512,13 +1502,11 @@
 */
 {
 	struct inode *ip;
-	struct fs *fs;
 	u_char *eae, *p;
 	unsigned easize;
 	int error, ealen;
 
 	ip = VTOI(ap->a_vp);
-	fs = ip->i_fs;
 
 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
 		return (EOPNOTSUPP);
@@ -1567,14 +1555,12 @@
 */
 {
 	struct inode *ip;
-	struct fs *fs;
 	u_char *eae, *p, *pe, *pn;
 	unsigned easize;
 	uint32_t ul;
 	int error, ealen;
 
 	ip = VTOI(ap->a_vp);
-	fs = ip->i_fs;
 
 	if (ap->a_vp->v_type == VCHR || ap->a_vp->v_type == VBLK)
 		return (EOPNOTSUPP);
Index: sys/ufs/ufs/ufs_bmap.c
===================================================================
--- sys/ufs/ufs/ufs_bmap.c
+++ sys/ufs/ufs/ufs_bmap.c
@@ -114,7 +114,6 @@
 	struct buf *bp;
 	struct ufsmount *ump;
 	struct mount *mp;
-	struct vnode *devvp;
 	struct indir a[NIADDR+1], *ap;
 	ufs2_daddr_t daddr;
 	ufs_lbn_t metalbn;
@@ -125,7 +124,6 @@
 	ip = VTOI(vp);
 	mp = vp->v_mount;
 	ump = VFSTOUFS(mp);
-	devvp = ump->um_devvp;
 
 	if (runp) {
 		maxrun = mp->mnt_iosize_max / mp->mnt_stat.f_iosize - 1;
Index: sys/ufs/ufs/ufs_dirhash.c
===================================================================
--- sys/ufs/ufs/ufs_dirhash.c
+++ sys/ufs/ufs/ufs_dirhash.c
@@ -190,9 +190,7 @@
 	struct dirhash *ndh;
 	struct dirhash *dh;
 	struct vnode *vp;
-	int error;
 
-	error = 0;
 	ndh = dh = NULL;
 	vp = ip->i_vnode;
 	for (;;) {
@@ -274,11 +272,9 @@
 ufsdirhash_acquire(struct inode *ip)
 {
 	struct dirhash *dh;
-	struct vnode *vp;
 
 	ASSERT_VOP_ELOCKED(ip->i_vnode, __FUNCTION__);
 
-	vp = ip->i_vnode;
 	dh = ip->i_dirhash;
 	if (dh == NULL)
 		return (NULL);
Index: sys/x86/iommu/busdma_dmar.c
===================================================================
--- sys/x86/iommu/busdma_dmar.c
+++ sys/x86/iommu/busdma_dmar.c
@@ -818,7 +818,6 @@
 	struct bus_dma_tag_dmar *tag;
 	struct bus_dmamap_dmar *map;
 	struct dmar_unit *unit;
-	struct dmar_ctx *ctx;
 
 	unit = arg;
 	DMAR_LOCK(unit);
@@ -826,7 +825,6 @@
 		TAILQ_REMOVE(&unit->delayed_maps, map, delay_link);
 		DMAR_UNLOCK(unit);
 		tag = map->tag;
-		ctx = map->tag->ctx;
 		map->cansleep = true;
 		map->locked = false;
 		bus_dmamap_load_mem((bus_dma_tag_t)tag, (bus_dmamap_t)map,
@@ -847,9 +845,7 @@
 static void
 dmar_bus_schedule_dmamap(struct dmar_unit *unit, struct bus_dmamap_dmar *map)
 {
-	struct dmar_ctx *ctx;
 
-	ctx = map->tag->ctx;
 	map->locked = false;
 	DMAR_LOCK(unit);
 	TAILQ_INSERT_TAIL(&unit->delayed_maps, map, delay_link);
Index: sys/x86/iommu/intel_idpgtbl.c
===================================================================
--- sys/x86/iommu/intel_idpgtbl.c
+++ sys/x86/iommu/intel_idpgtbl.c
@@ -108,7 +108,7 @@
 ctx_idmap_nextlvl(struct idpgtbl *tbl, int lvl, vm_pindex_t idx,
     dmar_gaddr_t addr)
 {
-	vm_page_t m, m1;
+	vm_page_t m1;
 	dmar_pte_t *pte;
 	struct sf_buf *sf;
 	dmar_gaddr_t f, pg_sz;
@@ -118,7 +118,7 @@
 	VM_OBJECT_ASSERT_LOCKED(tbl->pgtbl_obj);
 	if (addr >= tbl->maxaddr)
 		return;
-	m = dmar_pgalloc(tbl->pgtbl_obj, idx, DMAR_PGF_OBJL | DMAR_PGF_WAITOK |
+	(void)dmar_pgalloc(tbl->pgtbl_obj, idx, DMAR_PGF_OBJL | DMAR_PGF_WAITOK |
 	    DMAR_PGF_ZERO);
 	base = idx * DMAR_NPTEPG + 1; /* Index of the first child page of idx */
 	pg_sz = pglvl_page_size(tbl->pglvl, lvl);
@@ -598,7 +598,7 @@
 	dmar_pte_t *pte;
 	struct sf_buf *sf;
 	vm_pindex_t idx;
-	dmar_gaddr_t pg_sz, base1, size1;
+	dmar_gaddr_t pg_sz;
 	int lvl;
 
 	DMAR_CTX_ASSERT_PGLOCKED(ctx);
@@ -625,8 +625,6 @@
 	KASSERT((flags & ~DMAR_PGF_WAITOK) == 0, ("invalid flags %x", flags));
 
 	pg_sz = 0; /* silence gcc */
-	base1 = base;
-	size1 = size;
 	flags |= DMAR_PGF_OBJL;
 	TD_PREP_PINNED_ASSERT;