diff --git a/module/os/freebsd/zfs/vdev_file.c b/module/os/freebsd/zfs/vdev_file.c
index fc04a74761..cd1d75687c 100644
--- a/module/os/freebsd/zfs/vdev_file.c
+++ b/module/os/freebsd/zfs/vdev_file.c
@@ -286,10 +286,10 @@ vdev_file_io_start(zio_t *zio)
 	    TQ_SLEEP), !=, 0);
 }
 
-/* ARGSUSED */
 static void
 vdev_file_io_done(zio_t *zio)
 {
+	(void) zio;
 }
 
 vdev_ops_t vdev_file_ops = {
diff --git a/module/os/freebsd/zfs/zfs_racct.c b/module/os/freebsd/zfs/zfs_racct.c
index b46cc04626..883255bc19 100644
--- a/module/os/freebsd/zfs/zfs_racct.c
+++ b/module/os/freebsd/zfs/zfs_racct.c
@@ -37,6 +37,8 @@ zfs_racct_read(uint64_t size, uint64_t iops)
 		racct_add_force(curproc, RACCT_READIOPS, iops);
 		PROC_UNLOCK(curproc);
 	}
+#else
+	(void) size;
 #endif /* RACCT */
 }
 
@@ -51,5 +53,7 @@ zfs_racct_write(uint64_t size, uint64_t iops)
 		racct_add_force(curproc, RACCT_WRITEIOPS, iops);
 		PROC_UNLOCK(curproc);
 	}
+#else
+	(void) size;
 #endif /* RACCT */
 }
diff --git a/module/os/freebsd/zfs/zio_crypt.c b/module/os/freebsd/zfs/zio_crypt.c
index 832378a92a..038f2250e7 100644
--- a/module/os/freebsd/zfs/zio_crypt.c
+++ b/module/os/freebsd/zfs/zio_crypt.c
@@ -1033,7 +1033,6 @@ error:
  * and le_bswap indicates whether a byteswap is needed to get this block
  * into little endian format.
  */
-/* ARGSUSED */
 int
 zio_crypt_do_objset_hmacs(zio_crypt_key_t *key, void *data, uint_t datalen,
     boolean_t should_bswap, uint8_t *portable_mac, uint8_t *local_mac)
@@ -1242,13 +1241,13 @@ zio_crypt_do_indirect_mac_checksum_abd(boolean_t generate, abd_t *abd,
  * It also means we'll only return one zfs_uio_t.
  */
 
-/* ARGSUSED */
 static int
 zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
     uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap, zfs_uio_t *puio,
     zfs_uio_t *out_uio, uint_t *enc_len, uint8_t **authbuf, uint_t *auth_len,
     boolean_t *no_crypt)
 {
+	(void) puio;
 	uint8_t *aadbuf = zio_buf_alloc(datalen);
 	uint8_t *src, *dst, *slrp, *dlrp, *blkend, *aadp;
 	iovec_t *dst_iovecs;
@@ -1545,12 +1544,12 @@ zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 zio_crypt_init_uios_normal(boolean_t encrypt, uint8_t *plainbuf,
     uint8_t *cipherbuf, uint_t datalen, zfs_uio_t *puio, zfs_uio_t *out_uio,
     uint_t *enc_len)
 {
+	(void) puio;
 	int ret;
 	uint_t nr_plain = 1, nr_cipher = 2;
 	iovec_t *plain_iovecs = NULL, *cipher_iovecs = NULL;
diff --git a/module/os/linux/zfs/vdev_file.c b/module/os/linux/zfs/vdev_file.c
index bf8a13ae61..98338e604f 100644
--- a/module/os/linux/zfs/vdev_file.c
+++ b/module/os/linux/zfs/vdev_file.c
@@ -298,10 +298,10 @@ vdev_file_io_start(zio_t *zio)
 	    TQ_SLEEP), !=, TASKQID_INVALID);
 }
 
-/* ARGSUSED */
 static void
 vdev_file_io_done(zio_t *zio)
 {
+	(void) zio;
 }
 
 vdev_ops_t vdev_file_ops = {
diff --git a/module/os/linux/zfs/zfs_racct.c b/module/os/linux/zfs/zfs_racct.c
index 7897e0f9ed..ce623ef9d1 100644
--- a/module/os/linux/zfs/zfs_racct.c
+++ b/module/os/linux/zfs/zfs_racct.c
@@ -28,9 +28,11 @@
 void
 zfs_racct_read(uint64_t size, uint64_t iops)
 {
+	(void) size, (void) iops;
 }
 
 void
 zfs_racct_write(uint64_t size, uint64_t iops)
 {
+	(void) size, (void) iops;
 }
diff --git a/module/os/linux/zfs/zio_crypt.c b/module/os/linux/zfs/zio_crypt.c
index 52e62f4d1d..2c82be2d7d 100644
--- a/module/os/linux/zfs/zio_crypt.c
+++ b/module/os/linux/zfs/zio_crypt.c
@@ -1761,6 +1761,7 @@ zio_crypt_init_uios_normal(boolean_t encrypt, uint8_t *plainbuf,
     uint8_t *cipherbuf, uint_t datalen, zfs_uio_t *puio, zfs_uio_t *cuio,
     uint_t *enc_len)
 {
+	(void) encrypt;
 	int ret;
 	uint_t nr_plain = 1, nr_cipher = 2;
 	iovec_t *plain_iovecs = NULL, *cipher_iovecs = NULL;
diff --git a/module/zfs/abd.c b/module/zfs/abd.c
index bf39cd6133..8ee8e7e574 100644
--- a/module/zfs/abd.c
+++ b/module/zfs/abd.c
@@ -889,10 +889,10 @@ abd_copy_from_buf_off(abd_t *abd, const void *buf, size_t off, size_t size)
 	    &ba_ptr);
 }
 
-/*ARGSUSED*/
 static int
 abd_zero_off_cb(void *buf, size_t size, void *private)
 {
+	(void) private;
 	(void) memset(buf, 0, size);
 	return (0);
 }
@@ -967,10 +967,10 @@ abd_iterate_func2(abd_t *dabd, abd_t *sabd, size_t doff, size_t soff,
 	return (ret);
 }
 
-/*ARGSUSED*/
 static int
 abd_copy_off_cb(void *dbuf, void *sbuf, size_t size, void *private)
 {
+	(void) private;
 	(void) memcpy(dbuf, sbuf, size);
 	return (0);
 }
@@ -985,10 +985,10 @@ abd_copy_off(abd_t *dabd, abd_t *sabd, size_t doff, size_t soff, size_t size)
 	    abd_copy_off_cb, NULL);
 }
 
-/*ARGSUSED*/
 static int
 abd_cmp_cb(void *bufa, void *bufb, size_t size, void *private)
 {
+	(void) private;
 	return (memcmp(bufa, bufb, size));
 }
 
diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index abd5ba50c7..6ae67c9987 100644
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -1098,8 +1098,6 @@ static kmem_cache_t *buf_cache;
 static void
 buf_fini(void)
 {
-	int i;
-
 #if defined(_KERNEL)
 	/*
 	 * Large allocations which do not require contiguous pages
@@ -1111,7 +1109,7 @@ buf_fini(void)
 	kmem_free(buf_hash_table.ht_table,
 	    (buf_hash_table.ht_mask + 1) * sizeof (void *));
 #endif
-	for (i = 0; i < BUF_LOCKS; i++)
+	for (int i = 0; i < BUF_LOCKS; i++)
 		mutex_destroy(BUF_HASH_LOCK(i));
 	kmem_cache_destroy(hdr_full_cache);
 	kmem_cache_destroy(hdr_full_crypt_cache);
@@ -1123,10 +1121,10 @@ buf_fini(void)
  * Constructor callback - called when the cache is empty
  * and a new buf is requested.
  */
-/* ARGSUSED */
 static int
 hdr_full_cons(void *vbuf, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	arc_buf_hdr_t *hdr = vbuf;
 
 	bzero(hdr, HDR_FULL_SIZE);
@@ -1142,10 +1140,10 @@ hdr_full_cons(void *vbuf, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 hdr_full_crypt_cons(void *vbuf, void *unused, int kmflag)
 {
+	(void) unused;
 	arc_buf_hdr_t *hdr = vbuf;
 
 	hdr_full_cons(vbuf, unused, kmflag);
@@ -1155,10 +1153,10 @@ hdr_full_crypt_cons(void *vbuf, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 hdr_l2only_cons(void *vbuf, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	arc_buf_hdr_t *hdr = vbuf;
 
 	bzero(hdr, HDR_L2ONLY_SIZE);
@@ -1167,10 +1165,10 @@ hdr_l2only_cons(void *vbuf, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 buf_cons(void *vbuf, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	arc_buf_t *buf = vbuf;
 
 	bzero(buf, sizeof (arc_buf_t));
@@ -1184,10 +1182,10 @@ buf_cons(void *vbuf, void *unused, int kmflag)
  * Destructor callback - called when a cached buf is
  * no longer required.
  */
-/* ARGSUSED */
 static void
 hdr_full_dest(void *vbuf, void *unused)
 {
+	(void) unused;
 	arc_buf_hdr_t *hdr = vbuf;
 
 	ASSERT(HDR_EMPTY(hdr));
@@ -1198,30 +1196,30 @@ hdr_full_dest(void *vbuf, void *unused)
 	arc_space_return(HDR_FULL_SIZE, ARC_SPACE_HDRS);
 }
 
-/* ARGSUSED */
 static void
 hdr_full_crypt_dest(void *vbuf, void *unused)
 {
+	(void) unused;
 	arc_buf_hdr_t *hdr = vbuf;
 
 	hdr_full_dest(vbuf, unused);
 	arc_space_return(sizeof (hdr->b_crypt_hdr), ARC_SPACE_HDRS);
 }
 
-/* ARGSUSED */
 static void
 hdr_l2only_dest(void *vbuf, void *unused)
 {
-	arc_buf_hdr_t *hdr __maybe_unused = vbuf;
+	(void) unused;
+	arc_buf_hdr_t *hdr = vbuf;
 
 	ASSERT(HDR_EMPTY(hdr));
 	arc_space_return(HDR_L2ONLY_SIZE, ARC_SPACE_L2HDRS);
 }
 
-/* ARGSUSED */
 static void
 buf_dest(void *vbuf, void *unused)
 {
+	(void) unused;
 	arc_buf_t *buf = vbuf;
 
 	mutex_destroy(&buf->b_evict_lock);
@@ -1517,11 +1515,11 @@ arc_cksum_compute(arc_buf_t *buf)
 void
 arc_buf_sigsegv(int sig, siginfo_t *si, void *unused)
 {
+	(void) sig, (void) unused;
 	panic("Got SIGSEGV at address: 0x%lx\n", (long)si->si_addr);
 }
 #endif
 
-/* ARGSUSED */
 static void
 arc_buf_unwatch(arc_buf_t *buf)
 {
@@ -1530,10 +1528,11 @@ arc_buf_unwatch(arc_buf_t *buf)
 		ASSERT0(mprotect(buf->b_data, arc_buf_size(buf),
 		    PROT_READ | PROT_WRITE));
 	}
+#else
+	(void) buf;
 #endif
 }
 
-/* ARGSUSED */
 static void
 arc_buf_watch(arc_buf_t *buf)
 {
@@ -1541,6 +1540,8 @@ arc_buf_watch(arc_buf_t *buf)
 	if (arc_watch)
 		ASSERT0(mprotect(buf->b_data, arc_buf_size(buf),
 		    PROT_READ));
+#else
+	(void) buf;
 #endif
 }
 
@@ -1952,7 +1953,7 @@ error:
  * arc_buf_fill().
  */
 static void
-arc_buf_untransform_in_place(arc_buf_t *buf, kmutex_t *hash_lock)
+arc_buf_untransform_in_place(arc_buf_t *buf)
 {
 	arc_buf_hdr_t *hdr = buf->b_hdr;
 
@@ -2056,7 +2057,7 @@ arc_buf_fill(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb,
 
 			if (hash_lock != NULL)
 				mutex_enter(hash_lock);
-			arc_buf_untransform_in_place(buf, hash_lock);
+			arc_buf_untransform_in_place(buf);
 			if (hash_lock != NULL)
 				mutex_exit(hash_lock);
 
@@ -2342,6 +2343,7 @@ remove_reference(arc_buf_hdr_t *hdr, kmutex_t *hash_lock, void *tag)
 void
 arc_buf_info(arc_buf_t *ab, arc_buf_info_t *abi, int state_index)
 {
+	(void) state_index;
 	arc_buf_hdr_t *hdr = ab->b_hdr;
 	l1arc_buf_hdr_t *l1hdr = NULL;
 	l2arc_buf_hdr_t *l2hdr = NULL;
@@ -4850,10 +4852,11 @@ arc_kmem_reap_soon(void)
 	abd_cache_reap_now();
 }
 
-/* ARGSUSED */
 static boolean_t
 arc_evict_cb_check(void *arg, zthr_t *zthr)
 {
+	(void) arg, (void) zthr;
+
 #ifdef ZFS_DEBUG
 	/*
 	 * This is necessary in order to keep the kstat information
@@ -4893,10 +4896,11 @@ arc_evict_cb_check(void *arg, zthr_t *zthr)
  * Keep arc_size under arc_c by running arc_evict which evicts data
  * from the ARC.
  */
-/* ARGSUSED */
 static void
 arc_evict_cb(void *arg, zthr_t *zthr)
 {
+	(void) arg, (void) zthr;
+
 	uint64_t evicted = 0;
 	fstrans_cookie_t cookie = spl_fstrans_mark();
 
@@ -4933,10 +4937,11 @@ arc_evict_cb(void *arg, zthr_t *zthr)
 	spl_fstrans_unmark(cookie);
 }
 
-/* ARGSUSED */
 static boolean_t
 arc_reap_cb_check(void *arg, zthr_t *zthr)
 {
+	(void) arg, (void) zthr;
+
 	int64_t free_memory = arc_available_memory();
 	static int reap_cb_check_counter = 0;
 
@@ -4980,10 +4985,11 @@ arc_reap_cb_check(void *arg, zthr_t *zthr)
  * target size of the cache (arc_c), causing the arc_evict_cb()
  * to free more buffers.
  */
-/* ARGSUSED */
 static void
 arc_reap_cb(void *arg, zthr_t *zthr)
 {
+	(void) arg, (void) zthr;
+
 	int64_t free_memory;
 	fstrans_cookie_t cookie = spl_fstrans_mark();
 
@@ -5598,11 +5604,12 @@ arc_buf_access(arc_buf_t *buf)
 }
 
 /* a generic arc_read_done_func_t which you can use */
-/* ARGSUSED */
 void
 arc_bcopy_func(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
     arc_buf_t *buf, void *arg)
 {
+	(void) zio, (void) zb, (void) bp;
+
 	if (buf == NULL)
 		return;
 
@@ -5611,11 +5618,11 @@ arc_bcopy_func(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
 }
 
 /* a generic arc_read_done_func_t */
-/* ARGSUSED */
 void
 arc_getbuf_func(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
     arc_buf_t *buf, void *arg)
 {
+	(void) zb, (void) bp;
 	arc_buf_t **bufp = arg;
 
 	if (buf == NULL) {
@@ -9678,10 +9685,10 @@ l2arc_hdr_limit_reached(void)
  * This thread feeds the L2ARC at regular intervals.  This is the beating
  * heart of the L2ARC.
  */
-/* ARGSUSED */
 static void
 l2arc_feed_thread(void *unused)
 {
+	(void) unused;
 	callb_cpr_t cpr;
 	l2arc_dev_t *dev;
 	spa_t *spa;
diff --git a/module/zfs/bpobj.c b/module/zfs/bpobj.c
index e75ba5cccd..68f534c6b1 100644
--- a/module/zfs/bpobj.c
+++ b/module/zfs/bpobj.c
@@ -860,10 +860,10 @@ struct space_range_arg {
 	uint64_t uncomp;
 };
 
-/* ARGSUSED */
 static int
 space_range_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed, dmu_tx_t *tx)
 {
+	(void) bp_freed, (void) tx;
 	struct space_range_arg *sra = arg;
 
 	if (bp->blk_birth > sra->mintxg && bp->blk_birth <= sra->maxtxg) {
@@ -932,11 +932,11 @@ bpobj_space_range(bpobj_t *bpo, uint64_t mintxg, uint64_t maxtxg,
  * bpobj are designated as free or allocated that information is not preserved
  * in bplists.
  */
-/* ARGSUSED */
 int
 bplist_append_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
     dmu_tx_t *tx)
 {
+	(void) bp_freed, (void) tx;
 	bplist_t *bpl = arg;
 	bplist_append(bpl, bp);
 	return (0);
diff --git a/module/zfs/bptree.c b/module/zfs/bptree.c
index 1827a3c4e3..4e9a4825e2 100644
--- a/module/zfs/bptree.c
+++ b/module/zfs/bptree.c
@@ -147,11 +147,11 @@ bptree_add(objset_t *os, uint64_t obj, blkptr_t *bp, uint64_t birth_txg,
 	dmu_buf_rele(db, FTAG);
 }
 
-/* ARGSUSED */
 static int
 bptree_visit_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
+	(void) zilog, (void) dnp;
 	int err;
 	struct bptree_args *ba = arg;
 
diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index 1a298deb18..8443704c74 100644
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -280,10 +280,10 @@ static unsigned long dbuf_metadata_cache_target_bytes(void);
 uint_t dbuf_cache_hiwater_pct = 10;
 uint_t dbuf_cache_lowater_pct = 10;
 
-/* ARGSUSED */
 static int
 dbuf_cons(void *vdb, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	dmu_buf_impl_t *db = vdb;
 	bzero(db, sizeof (dmu_buf_impl_t));
 
@@ -296,10 +296,10 @@ dbuf_cons(void *vdb, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 dbuf_dest(void *vdb, void *unused)
 {
+	(void) unused;
 	dmu_buf_impl_t *db = vdb;
 	mutex_destroy(&db->db_mtx);
 	rw_destroy(&db->db_rwlock);
@@ -783,10 +783,10 @@ dbuf_evict_one(void)
  * of the dbuf cache is at or below the maximum size. Once the dbuf is aged
  * out of the cache it is destroyed and becomes eligible for arc eviction.
  */
-/* ARGSUSED */
 static void
 dbuf_evict_thread(void *unused)
 {
+	(void) unused;
 	callb_cpr_t cpr;
 
 	CALLB_CPR_INIT(&cpr, &dbuf_evict_lock, callb_generic_cpr, FTAG);
@@ -1339,6 +1339,7 @@ static void
 dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
     arc_buf_t *buf, void *vdb)
 {
+	(void) zb, (void) bp;
 	dmu_buf_impl_t *db = vdb;
 
 	mutex_enter(&db->db_mtx);
@@ -1432,7 +1433,7 @@ dbuf_handle_indirect_hole(dmu_buf_impl_t *db, dnode_t *dn)
  * was taken, ENOENT if no action was taken.
  */
 static int
-dbuf_read_hole(dmu_buf_impl_t *db, dnode_t *dn, uint32_t flags)
+dbuf_read_hole(dmu_buf_impl_t *db, dnode_t *dn)
 {
 	ASSERT(MUTEX_HELD(&db->db_mtx));
 
@@ -1548,7 +1549,7 @@ dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags,
 		goto early_unlock;
 	}
 
-	err = dbuf_read_hole(db, dn, flags);
+	err = dbuf_read_hole(db, dn);
 	if (err == 0)
 		goto early_unlock;
 
@@ -2678,10 +2679,10 @@ dbuf_override_impl(dmu_buf_impl_t *db, const blkptr_t *bp, dmu_tx_t *tx)
 	dl->dr_overridden_by.blk_birth = dr->dr_txg;
 }
 
-/* ARGSUSED */
 void
 dmu_buf_fill_done(dmu_buf_t *dbuf, dmu_tx_t *tx)
 {
+	(void) tx;
 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
 	dbuf_states_t old_state;
 	mutex_enter(&db->db_mtx);
@@ -3198,6 +3199,7 @@ static void
 dbuf_issue_final_prefetch_done(zio_t *zio, const zbookmark_phys_t *zb,
     const blkptr_t *iobp, arc_buf_t *abuf, void *private)
 {
+	(void) zio, (void) zb, (void) iobp;
 	dbuf_prefetch_arg_t *dpa = private;
 
 	dbuf_prefetch_fini(dpa, B_TRUE);
@@ -3246,6 +3248,7 @@ static void
 dbuf_prefetch_indirect_done(zio_t *zio, const zbookmark_phys_t *zb,
     const blkptr_t *iobp, arc_buf_t *abuf, void *private)
 {
+	(void) zb, (void) iobp;
 	dbuf_prefetch_arg_t *dpa = private;
 
 	ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel);
@@ -4512,10 +4515,10 @@ dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx)
 	}
 }
 
-/* ARGSUSED */
 static void
 dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
 {
+	(void) buf;
 	dmu_buf_impl_t *db = vdb;
 	dnode_t *dn;
 	blkptr_t *bp = zio->io_bp;
@@ -4603,7 +4606,6 @@ dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
 	dmu_buf_unlock_parent(db, dblt, FTAG);
 }
 
-/* ARGSUSED */
 /*
  * This function gets called just prior to running through the compression
  * stage of the zio pipeline. If we're an indirect block comprised of only
@@ -4614,6 +4616,7 @@ dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
 static void
 dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
 {
+	(void) zio, (void) buf;
 	dmu_buf_impl_t *db = vdb;
 	dnode_t *dn;
 	blkptr_t *bp;
@@ -4657,10 +4660,10 @@ dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
  * so this callback allows us to retire dirty space gradually, as the physical
  * i/os complete.
  */
-/* ARGSUSED */
 static void
 dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
 {
+	(void) buf;
 	dmu_buf_impl_t *db = arg;
 	objset_t *os = db->db_objset;
 	dsl_pool_t *dp = dmu_objset_pool(os);
@@ -4679,10 +4682,10 @@ dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg)
 	dsl_pool_undirty_space(dp, delta, zio->io_txg);
 }
 
-/* ARGSUSED */
 static void
 dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
 {
+	(void) buf;
 	dmu_buf_impl_t *db = vdb;
 	blkptr_t *bp_orig = &zio->io_bp_orig;
 	blkptr_t *bp = db->db_blkptr;
diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c
index 5ce11e86da..e6f391066d 100644
--- a/module/zfs/dmu.c
+++ b/module/zfs/dmu.c
@@ -816,13 +816,14 @@ get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks)
  * otherwise return false.
  * Used below in dmu_free_long_range_impl() to enable abort when unmounting
  */
-/*ARGSUSED*/
 static boolean_t
 dmu_objset_zfs_unmounting(objset_t *os)
 {
 #ifdef _KERNEL
 	if (dmu_objset_type(os) == DMU_OST_ZFS)
 		return (zfs_get_vfs_flag_unmounted(os));
+#else
+	(void) os;
 #endif
 	return (B_FALSE);
 }
@@ -1504,10 +1505,10 @@ typedef struct {
 	dmu_tx_t		*dsa_tx;
 } dmu_sync_arg_t;
 
-/* ARGSUSED */
 static void
 dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg)
 {
+	(void) buf;
 	dmu_sync_arg_t *dsa = varg;
 	dmu_buf_t *db = dsa->dsa_zgd->zgd_db;
 	blkptr_t *bp = zio->io_bp;
@@ -1532,10 +1533,10 @@ dmu_sync_late_arrival_ready(zio_t *zio)
 	dmu_sync_ready(zio, NULL, zio->io_private);
 }
 
-/* ARGSUSED */
 static void
 dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg)
 {
+	(void) buf;
 	dmu_sync_arg_t *dsa = varg;
 	dbuf_dirty_record_t *dr = dsa->dsa_dr;
 	dmu_buf_impl_t *db = dr->dr_dbuf;
@@ -2276,10 +2277,10 @@ byteswap_uint16_array(void *vbuf, size_t size)
 		buf[i] = BSWAP_16(buf[i]);
 }
 
-/* ARGSUSED */
 void
 byteswap_uint8_array(void *vbuf, size_t size)
 {
+	(void) vbuf, (void) size;
 }
 
 void
diff --git a/module/zfs/dmu_diff.c b/module/zfs/dmu_diff.c
index a573a2e1bd..1382da267d 100644
--- a/module/zfs/dmu_diff.c
+++ b/module/zfs/dmu_diff.c
@@ -108,11 +108,11 @@ report_dnode(dmu_diffarg_t *da, uint64_t object, dnode_phys_t *dnp)
 	(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
 	(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
 
-/* ARGSUSED */
 static int
 diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
+	(void) zilog;
 	dmu_diffarg_t *da = arg;
 	int err = 0;
 
diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c
index b30a9d6190..a8975797e8 100644
--- a/module/zfs/dmu_objset.c
+++ b/module/zfs/dmu_objset.c
@@ -751,9 +751,9 @@ static int
 dmu_objset_own_impl(dsl_dataset_t *ds, dmu_objset_type_t type,
     boolean_t readonly, boolean_t decrypt, void *tag, objset_t **osp)
 {
-	int err;
+	(void) tag;
 
-	err = dmu_objset_from_ds(ds, osp);
+	int err = dmu_objset_from_ds(ds, osp);
 	if (err != 0) {
 		return (err);
 	} else if (type != DMU_OST_ANY && type != (*osp)->os_phys->os_type) {
@@ -1157,7 +1157,6 @@ typedef struct dmu_objset_create_arg {
 	dsl_crypto_params_t *doca_dcp;
 } dmu_objset_create_arg_t;
 
-/*ARGSUSED*/
 static int
 dmu_objset_create_check(void *arg, dmu_tx_t *tx)
 {
@@ -1353,7 +1352,6 @@ typedef struct dmu_objset_clone_arg {
 	proc_t *doca_proc;
 } dmu_objset_clone_arg_t;
 
-/*ARGSUSED*/
 static int
 dmu_objset_clone_check(void *arg, dmu_tx_t *tx)
 {
@@ -1565,10 +1563,10 @@ dmu_objset_sync_dnodes(multilist_sublist_t *list, dmu_tx_t *tx)
 	}
 }
 
-/* ARGSUSED */
 static void
 dmu_objset_write_ready(zio_t *zio, arc_buf_t *abuf, void *arg)
 {
+	(void) abuf;
 	blkptr_t *bp = zio->io_bp;
 	objset_t *os = arg;
 	dnode_phys_t *dnp = &os->os_phys->os_meta_dnode;
@@ -1596,10 +1594,10 @@ dmu_objset_write_ready(zio_t *zio, arc_buf_t *abuf, void *arg)
 		rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG);
 }
 
-/* ARGSUSED */
 static void
 dmu_objset_write_done(zio_t *zio, arc_buf_t *abuf, void *arg)
 {
+	(void) abuf;
 	blkptr_t *bp = zio->io_bp;
 	blkptr_t *bp_orig = &zio->io_bp_orig;
 	objset_t *os = arg;
diff --git a/module/zfs/dmu_redact.c b/module/zfs/dmu_redact.c
index fdbdf7d6e8..7efe423d35 100644
--- a/module/zfs/dmu_redact.c
+++ b/module/zfs/dmu_redact.c
@@ -249,11 +249,11 @@ zfs_get_deleteq(objset_t *os)
  * Third, if there is a deleted object, we need to create a redaction record for
  * all of the blocks in that object.
  */
-/*ARGSUSED*/
 static int
 redact_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg)
 {
+	(void) spa, (void) zilog;
 	struct redact_thread_arg *rta = arg;
 	struct redact_record *record;
 
diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c
index 2f2fd4c3d6..6cff7fd580 100644
--- a/module/zfs/dmu_send.c
+++ b/module/zfs/dmu_send.c
@@ -1097,11 +1097,11 @@ range_alloc(enum type type, uint64_t object, uint64_t start_blkid,
  * This is the callback function to traverse_dataset that acts as a worker
  * thread for dmu_send_impl.
  */
-/*ARGSUSED*/
 static int
 send_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const struct dnode_phys *dnp, void *arg)
 {
+	(void) zilog;
 	struct send_thread_arg *sta = arg;
 	struct send_range *record;
 
@@ -2155,6 +2155,7 @@ setup_resume_points(struct dmu_send_params *dspp,
     struct send_merge_thread_arg *smt_arg, boolean_t resuming, objset_t *os,
     redaction_list_t *redact_rl, nvlist_t *nvl)
 {
+	(void) smt_arg;
 	dsl_dataset_t *to_ds = dspp->to_ds;
 	int err = 0;
 
diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c
index 862c0bf404..2f1c2978b3 100644
--- a/module/zfs/dmu_traverse.c
+++ b/module/zfs/dmu_traverse.c
@@ -560,11 +560,11 @@ traverse_dnode(traverse_data_t *td, const blkptr_t *bp, const dnode_phys_t *dnp,
 	return (err);
 }
 
-/* ARGSUSED */
 static int
 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
+	(void) zilog, (void) dnp;
 	prefetch_data_t *pfd = arg;
 	int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
 	arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH |
diff --git a/module/zfs/dmu_zfetch.c b/module/zfs/dmu_zfetch.c
index 043344a137..f31728eae0 100644
--- a/module/zfs/dmu_zfetch.c
+++ b/module/zfs/dmu_zfetch.c
@@ -260,6 +260,7 @@ dmu_zfetch_stream_create(zfetch_t *zf, uint64_t blkid)
 static void
 dmu_zfetch_stream_done(void *arg, boolean_t io_issued)
 {
+	(void) io_issued;
 	zstream_t *zs = arg;
 
 	if (zfs_refcount_remove(&zs->zs_refs, NULL) == 0)
diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
index 658b556095..7b53b7cd05 100644
--- a/module/zfs/dnode.c
+++ b/module/zfs/dnode.c
@@ -108,12 +108,11 @@ dbuf_compare(const void *x1, const void *x2)
 	return (TREE_PCMP(d1, d2));
 }
 
-/* ARGSUSED */
 static int
 dnode_cons(void *arg, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	dnode_t *dn = arg;
-	int i;
 
 	rw_init(&dn->dn_struct_rwlock, NULL, RW_NOLOCKDEP, NULL);
 	mutex_init(&dn->dn_mtx, NULL, MUTEX_DEFAULT, NULL);
@@ -139,7 +138,7 @@ dnode_cons(void *arg, void *unused, int kmflag)
 	bzero(&dn->dn_next_blksz[0], sizeof (dn->dn_next_blksz));
 	bzero(&dn->dn_next_maxblkid[0], sizeof (dn->dn_next_maxblkid));
 
-	for (i = 0; i < TXG_SIZE; i++) {
+	for (int i = 0; i < TXG_SIZE; i++) {
 		multilist_link_init(&dn->dn_dirty_link[i]);
 		dn->dn_free_ranges[i] = NULL;
 		list_create(&dn->dn_dirty_records[i],
@@ -174,11 +173,10 @@ dnode_cons(void *arg, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 dnode_dest(void *arg, void *unused)
 {
-	int i;
+	(void) unused;
 	dnode_t *dn = arg;
 
 	rw_destroy(&dn->dn_struct_rwlock);
@@ -190,7 +188,7 @@ dnode_dest(void *arg, void *unused)
 	zfs_refcount_destroy(&dn->dn_tx_holds);
 	ASSERT(!list_link_active(&dn->dn_link));
 
-	for (i = 0; i < TXG_SIZE; i++) {
+	for (int i = 0; i < TXG_SIZE; i++) {
 		ASSERT(!multilist_link_active(&dn->dn_dirty_link[i]));
 		ASSERT3P(dn->dn_free_ranges[i], ==, NULL);
 		list_destroy(&dn->dn_dirty_records[i]);
@@ -889,7 +887,6 @@ dnode_move_impl(dnode_t *odn, dnode_t *ndn)
 	odn->dn_moved = (uint8_t)-1;
 }
 
-/*ARGSUSED*/
 static kmem_cbrc_t
 dnode_move(void *buf, void *newbuf, size_t size, void *arg)
 {
diff --git a/module/zfs/dsl_bookmark.c b/module/zfs/dsl_bookmark.c
index bead7da223..b8e3523ffc 100644
--- a/module/zfs/dsl_bookmark.c
+++ b/module/zfs/dsl_bookmark.c
@@ -1203,7 +1203,6 @@ dsl_redaction_list_long_rele(redaction_list_t *rl, void *tag)
 	(void) zfs_refcount_remove(&rl->rl_longholds, tag);
 }
 
-/* ARGSUSED */
 static void
 redaction_list_evict_sync(void *rlu)
 {
@@ -1470,10 +1469,11 @@ dsl_bookmark_next_changed(dsl_dataset_t *head, dsl_dataset_t *origin,
  * Adjust the FBN of any bookmarks that reference this block, whose "next"
  * is the head dataset.
  */
-/* ARGSUSED */
 void
 dsl_bookmark_block_killed(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
 {
+	(void) tx;
+
 	/*
 	 * Iterate over bookmarks whose "next" is the head dataset.
 	 */
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index f99964511a..4623bcec4e 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -2943,11 +2943,11 @@ typedef struct dsl_dataset_rename_snapshot_arg {
 	dmu_tx_t *ddrsa_tx;
 } dsl_dataset_rename_snapshot_arg_t;
 
-/* ARGSUSED */
 static int
 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
     dsl_dataset_t *hds, void *arg)
 {
+	(void) dp;
 	dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
 	int error;
 	uint64_t val;
@@ -4305,7 +4305,6 @@ typedef struct dsl_dataset_set_qr_arg {
 } dsl_dataset_set_qr_arg_t;
 
 
-/* ARGSUSED */
 static int
 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
 {
@@ -4512,7 +4511,6 @@ typedef struct dsl_dataset_set_compression_arg {
 	uint64_t ddsca_value;
 } dsl_dataset_set_compression_arg_t;
 
-/* ARGSUSED */
 static int
 dsl_dataset_set_compression_check(void *arg, dmu_tx_t *tx)
 {
diff --git a/module/zfs/dsl_destroy.c b/module/zfs/dsl_destroy.c
index a2748197f2..b32929b332 100644
--- a/module/zfs/dsl_destroy.c
+++ b/module/zfs/dsl_destroy.c
@@ -699,11 +699,11 @@ struct killarg {
 	dmu_tx_t *tx;
 };
 
-/* ARGSUSED */
 static int
 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
+	(void) spa, (void) dnp;
 	struct killarg *ka = arg;
 	dmu_tx_t *tx = ka->tx;
 
@@ -1246,10 +1246,10 @@ dsl_destroy_head(const char *name)
  * inconsistent datasets, even if we encounter an error trying to
  * process one of them.
  */
-/* ARGSUSED */
 int
 dsl_destroy_inconsistent(const char *dsname, void *arg)
 {
+	(void) arg;
 	objset_t *os;
 
 	if (dmu_objset_hold(dsname, FTAG, &os) == 0) {
diff --git a/module/zfs/dsl_dir.c b/module/zfs/dsl_dir.c
index 84caace4db..bd5e0c2f62 100644
--- a/module/zfs/dsl_dir.c
+++ b/module/zfs/dsl_dir.c
@@ -764,6 +764,8 @@ dsl_enforce_ds_ss_limits(dsl_dir_t *dd, zfs_prop_t prop,
 	 */
 	if (secpolicy_zfs_proc(cr, proc) == 0)
 		return (ENFORCE_NEVER);
+#else
+	(void) proc;
 #endif
 
 	if ((obj = dsl_dir_phys(dd)->dd_head_dataset_obj) == 0)
@@ -1896,10 +1898,10 @@ typedef struct dsl_valid_rename_arg {
 	int nest_delta;
 } dsl_valid_rename_arg_t;
 
-/* ARGSUSED */
 static int
 dsl_valid_rename(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
 {
+	(void) dp;
 	dsl_valid_rename_arg_t *dvra = arg;
 	char namebuf[ZFS_MAX_DATASET_NAME_LEN];
 
@@ -2396,6 +2398,7 @@ dsl_dir_activity_in_progress(dsl_dir_t *dd, dsl_dataset_t *ds,
 		 * The delete queue is ZPL specific, and libzpool doesn't have
 		 * it. It doesn't make sense to wait for it.
 		 */
+		(void) ds;
 		*in_progress = B_FALSE;
 		break;
 #endif
diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c
index 20bae9d94c..5d1522a7bf 100644
--- a/module/zfs/dsl_pool.c
+++ b/module/zfs/dsl_pool.c
@@ -476,8 +476,8 @@ dsl_pool_destroy_obsolete_bpobj(dsl_pool_t *dp, dmu_tx_t *tx)
 }
 
 dsl_pool_t *
-dsl_pool_create(spa_t *spa, nvlist_t *zplprops, dsl_crypto_params_t *dcp,
-    uint64_t txg)
+dsl_pool_create(spa_t *spa, nvlist_t *zplprops __attribute__((unused)),
+    dsl_crypto_params_t *dcp, uint64_t txg)
 {
 	int err;
 	dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
diff --git a/module/zfs/dsl_prop.c b/module/zfs/dsl_prop.c
index dfa04d7681..0089edf868 100644
--- a/module/zfs/dsl_prop.c
+++ b/module/zfs/dsl_prop.c
@@ -504,10 +504,10 @@ dsl_prop_hascb(dsl_dataset_t *ds)
 	return (!list_is_empty(&ds->ds_prop_cbs));
 }
 
-/* ARGSUSED */
 static int
 dsl_prop_notify_all_cb(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
 {
+	(void) arg;
 	dsl_dir_t *dd = ds->ds_dir;
 	dsl_prop_record_t *pr;
 	dsl_prop_cb_record_t *cbr;
diff --git a/module/zfs/dsl_scan.c b/module/zfs/dsl_scan.c
index d25c067dfb..859a865dd7 100644
--- a/module/zfs/dsl_scan.c
+++ b/module/zfs/dsl_scan.c
@@ -705,10 +705,10 @@ dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx, state_sync_type_t sync_type)
 	}
 }
 
-/* ARGSUSED */
 int
 dsl_scan_setup_check(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
 	vdev_t *rvd = scn->scn_dp->dp_spa->spa_root_vdev;
 
@@ -859,7 +859,6 @@ dsl_scan(dsl_pool_t *dp, pool_scan_func_t func)
 	    dsl_scan_setup_sync, &func, 0, ZFS_SPACE_CHECK_EXTRA_RESERVED));
 }
 
-/* ARGSUSED */
 static void
 dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx)
 {
@@ -1006,10 +1005,10 @@ dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx)
 	ASSERT(!dsl_scan_is_running(scn));
 }
 
-/* ARGSUSED */
 static int
 dsl_scan_cancel_check(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
 
 	if (!dsl_scan_is_running(scn))
@@ -1017,10 +1016,10 @@ dsl_scan_cancel_check(void *arg, dmu_tx_t *tx)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan;
 
 	dsl_scan_done(scn, B_FALSE, tx);
@@ -1383,11 +1382,11 @@ typedef struct zil_scan_arg {
 	zil_header_t	*zsa_zh;
 } zil_scan_arg_t;
 
-/* ARGSUSED */
 static int
 dsl_scan_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg,
     uint64_t claim_txg)
 {
+	(void) zilog;
 	zil_scan_arg_t *zsa = arg;
 	dsl_pool_t *dp = zsa->zsa_dp;
 	dsl_scan_t *scn = dp->dp_scan;
@@ -1414,11 +1413,11 @@ dsl_scan_zil_block(zilog_t *zilog, const blkptr_t *bp, void *arg,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 dsl_scan_zil_record(zilog_t *zilog, const lr_t *lrc, void *arg,
     uint64_t claim_txg)
 {
+	(void) zilog;
 	if (lrc->lrc_txtype == TX_WRITE) {
 		zil_scan_arg_t *zsa = arg;
 		dsl_pool_t *dp = zsa->zsa_dp;
@@ -1643,6 +1642,7 @@ static void
 dsl_scan_prefetch_cb(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
     arc_buf_t *buf, void *private)
 {
+	(void) zio;
 	scan_prefetch_ctx_t *spc = private;
 	dsl_scan_t *scn = spc->spc_scn;
 	spa_t *spa = scn->scn_dp->dp_spa;
@@ -1702,7 +1702,6 @@ out:
 	scan_prefetch_ctx_rele(spc, scn);
 }
 
-/* ARGSUSED */
 static void
 dsl_scan_prefetch_thread(void *arg)
 {
@@ -2340,7 +2339,6 @@ dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx)
 	dsl_scan_sync_state(scn, tx, SYNC_CACHED);
 }
 
-/* ARGSUSED */
 static int
 enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
 {
@@ -2525,10 +2523,10 @@ out:
 	dsl_dataset_rele(ds, FTAG);
 }
 
-/* ARGSUSED */
 static int
 enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
 {
+	(void) arg;
 	dsl_dataset_t *ds;
 	int err;
 	dsl_scan_t *scn = dp->dp_scan;
@@ -2564,16 +2562,15 @@ enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
 	return (0);
 }
 
-/* ARGSUSED */
 void
 dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum,
     ddt_entry_t *dde, dmu_tx_t *tx)
 {
+	(void) tx;
 	const ddt_key_t *ddk = &dde->dde_key;
 	ddt_phys_t *ddp = dde->dde_phys;
 	blkptr_t bp;
 	zbookmark_phys_t zb = { 0 };
-	int p;
 
 	if (!dsl_scan_is_running(scn))
 		return;
@@ -2592,7 +2589,7 @@ dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum,
 	if (scn->scn_done_txg != 0)
 		return;
 
-	for (p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
+	for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
 		if (ddp->ddp_phys_birth == 0 ||
 		    ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg)
 			continue;
diff --git a/module/zfs/dsl_synctask.c b/module/zfs/dsl_synctask.c
index 148e8fff24..9fc9d4011d 100644
--- a/module/zfs/dsl_synctask.c
+++ b/module/zfs/dsl_synctask.c
@@ -32,10 +32,10 @@
 
 #define	DST_AVG_BLKSHIFT 14
 
-/* ARGSUSED */
 static int
 dsl_null_checkfunc(void *arg, dmu_tx_t *tx)
 {
+	(void) arg, (void) tx;
 	return (0);
 }
 
diff --git a/module/zfs/fm.c b/module/zfs/fm.c
index cdf0fcf715..f4b001b278 100644
--- a/module/zfs/fm.c
+++ b/module/zfs/fm.c
@@ -483,17 +483,17 @@ zfs_zevent_destroy(zfs_zevent_t *ze)
 /*
  * Wrappers for FM nvlist allocators
  */
-/* ARGSUSED */
 static void *
 i_fm_alloc(nv_alloc_t *nva, size_t size)
 {
+	(void) nva;
 	return (kmem_zalloc(size, KM_SLEEP));
 }
 
-/* ARGSUSED */
 static void
 i_fm_free(nv_alloc_t *nva, void *buf, size_t size)
 {
+	(void) nva;
 	kmem_free(buf, size);
 }
 
diff --git a/module/zfs/gzip.c b/module/zfs/gzip.c
index e2c6e59969..48191241bd 100644
--- a/module/zfs/gzip.c
+++ b/module/zfs/gzip.c
@@ -83,10 +83,10 @@ gzip_compress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 	return ((size_t)dstlen);
 }
 
-/*ARGSUSED*/
 int
 gzip_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 {
+	(void) n;
 	zlen_t dstlen = d_len;
 
 	ASSERT(d_len >= s_len);
diff --git a/module/zfs/lz4.c b/module/zfs/lz4.c
index 4b46e69489..eba8f01b50 100644
--- a/module/zfs/lz4.c
+++ b/module/zfs/lz4.c
@@ -46,11 +46,11 @@ static int LZ4_compress64kCtx(void *ctx, const char *source, char *dest,
 
 static kmem_cache_t *lz4_cache;
 
-/*ARGSUSED*/
 size_t
 lz4_compress_zfs(void *s_start, void *d_start, size_t s_len,
     size_t d_len, int n)
 {
+	(void) n;
 	uint32_t bufsiz;
 	char *dest = d_start;
 
@@ -74,11 +74,11 @@ lz4_compress_zfs(void *s_start, void *d_start, size_t s_len,
 	return (bufsiz + sizeof (bufsiz));
 }
 
-/*ARGSUSED*/
 int
 lz4_decompress_zfs(void *s_start, void *d_start, size_t s_len,
     size_t d_len, int n)
 {
+	(void) n;
 	const char *src = s_start;
 	uint32_t bufsiz = BE_IN32(src);
 
@@ -463,7 +463,6 @@ LZ4_NbCommonBytes(register U32 val)
 
 /* Compression functions */
 
-/*ARGSUSED*/
 static int
 LZ4_compressCtx(void *ctx, const char *source, char *dest, int isize,
     int osize)
@@ -654,7 +653,6 @@ LZ4_compressCtx(void *ctx, const char *source, char *dest, int isize,
 	HASHLOG64K))
 #define	LZ4_HASH64K_VALUE(p)	LZ4_HASH64K_FUNCTION(A32(p))
 
-/*ARGSUSED*/
 static int
 LZ4_compress64kCtx(void *ctx, const char *source, char *dest, int isize,
     int osize)
diff --git a/module/zfs/lzjb.c b/module/zfs/lzjb.c
index a478e64c51..1c536b1103 100644
--- a/module/zfs/lzjb.c
+++ b/module/zfs/lzjb.c
@@ -45,10 +45,10 @@
 #define	OFFSET_MASK	((1 << (16 - MATCH_BITS)) - 1)
 #define	LEMPEL_SIZE	1024
 
-/*ARGSUSED*/
 size_t
 lzjb_compress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 {
+	(void) n;
 	uchar_t *src = s_start;
 	uchar_t *dst = d_start;
 	uchar_t *cpy;
@@ -100,10 +100,10 @@ lzjb_compress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 	return (dst - (uchar_t *)d_start);
 }
 
-/*ARGSUSED*/
 int
 lzjb_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
 {
+	(void) s_len, (void) n;
 	uchar_t *src = s_start;
 	uchar_t *dst = d_start;
 	uchar_t *d_end = (uchar_t *)d_start + d_len;
diff --git a/module/zfs/metaslab.c b/module/zfs/metaslab.c
index d1fee70f00..9e216c38d9 100644
--- a/module/zfs/metaslab.c
+++ b/module/zfs/metaslab.c
@@ -1406,7 +1406,6 @@ metaslab_size_tree_full_load(range_tree_t *rt)
  * Create any block allocator specific components. The current allocators
  * rely on using both a size-ordered range_tree_t and an array of uint64_t's.
  */
-/* ARGSUSED */
 static void
 metaslab_rt_create(range_tree_t *rt, void *arg)
 {
@@ -1431,10 +1430,10 @@ metaslab_rt_create(range_tree_t *rt, void *arg)
 	mrap->mra_floor_shift = metaslab_by_size_min_shift;
 }
 
-/* ARGSUSED */
 static void
 metaslab_rt_destroy(range_tree_t *rt, void *arg)
 {
+	(void) rt;
 	metaslab_rt_arg_t *mrap = arg;
 	zfs_btree_t *size_tree = mrap->mra_bt;
 
@@ -1442,7 +1441,6 @@ metaslab_rt_destroy(range_tree_t *rt, void *arg)
 	kmem_free(mrap, sizeof (*mrap));
 }
 
-/* ARGSUSED */
 static void
 metaslab_rt_add(range_tree_t *rt, range_seg_t *rs, void *arg)
 {
@@ -1456,7 +1454,6 @@ metaslab_rt_add(range_tree_t *rt, range_seg_t *rs, void *arg)
 	zfs_btree_add(size_tree, rs);
 }
 
-/* ARGSUSED */
 static void
 metaslab_rt_remove(range_tree_t *rt, range_seg_t *rs, void *arg)
 {
@@ -1470,7 +1467,6 @@ metaslab_rt_remove(range_tree_t *rt, range_seg_t *rs, void *arg)
 	zfs_btree_remove(size_tree, rs);
 }
 
-/* ARGSUSED */
 static void
 metaslab_rt_vacate(range_tree_t *rt, void *arg)
 {
@@ -2240,6 +2236,8 @@ metaslab_potentially_evict(metaslab_class_t *mc)
 			inuse = spl_kmem_cache_inuse(zfs_btree_leaf_cache);
 		}
 	}
+#else
+	(void) mc;
 #endif
 }
 
@@ -4721,7 +4719,6 @@ metaslab_active_mask_verify(metaslab_t *msp)
 	}
 }
 
-/* ARGSUSED */
 static uint64_t
 metaslab_group_alloc_normal(metaslab_group_t *mg, zio_alloc_list_t *zal,
     uint64_t asize, uint64_t txg, boolean_t want_unique, dva_t *dva, int d,
@@ -5347,11 +5344,11 @@ metaslab_free_concrete(vdev_t *vd, uint64_t offset, uint64_t asize,
 	mutex_exit(&msp->ms_lock);
 }
 
-/* ARGSUSED */
 void
 metaslab_free_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset,
     uint64_t size, void *arg)
 {
+	(void) inner_offset;
 	boolean_t *checkpoint = arg;
 
 	ASSERT3P(checkpoint, !=, NULL);
@@ -5717,11 +5714,11 @@ typedef struct metaslab_claim_cb_arg_t {
 	int		mcca_error;
 } metaslab_claim_cb_arg_t;
 
-/* ARGSUSED */
 static void
 metaslab_claim_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset,
     uint64_t size, void *arg)
 {
+	(void) inner_offset;
 	metaslab_claim_cb_arg_t *mcca_arg = arg;
 
 	if (mcca_arg->mcca_error == 0) {
@@ -5973,11 +5970,12 @@ metaslab_fastwrite_unmark(spa_t *spa, const blkptr_t *bp)
 	spa_config_exit(spa, SCL_VDEV, FTAG);
 }
 
-/* ARGSUSED */
 static void
 metaslab_check_free_impl_cb(uint64_t inner, vdev_t *vd, uint64_t offset,
     uint64_t size, void *arg)
 {
+	(void) inner, (void) arg;
+
 	if (vd->vdev_ops == &vdev_indirect_ops)
 		return;
 
diff --git a/module/zfs/range_tree.c b/module/zfs/range_tree.c
index 595918e5a7..67910f9ffd 100644
--- a/module/zfs/range_tree.c
+++ b/module/zfs/range_tree.c
@@ -741,7 +741,6 @@ range_tree_is_empty(range_tree_t *rt)
 	return (range_tree_space(rt) == 0);
 }
 
-/* ARGSUSED */
 void
 rt_btree_create(range_tree_t *rt, void *arg)
 {
@@ -764,35 +763,34 @@ rt_btree_create(range_tree_t *rt, void *arg)
 	zfs_btree_create(size_tree, rt->rt_btree_compare, size);
 }
 
-/* ARGSUSED */
 void
 rt_btree_destroy(range_tree_t *rt, void *arg)
 {
+	(void) rt;
 	zfs_btree_t *size_tree = arg;
 	ASSERT0(zfs_btree_numnodes(size_tree));
 
 	zfs_btree_destroy(size_tree);
 }
 
-/* ARGSUSED */
 void
 rt_btree_add(range_tree_t *rt, range_seg_t *rs, void *arg)
 {
+	(void) rt;
 	zfs_btree_t *size_tree = arg;
 
 	zfs_btree_add(size_tree, rs);
 }
 
-/* ARGSUSED */
 void
 rt_btree_remove(range_tree_t *rt, range_seg_t *rs, void *arg)
 {
+	(void) rt;
 	zfs_btree_t *size_tree = arg;
 
 	zfs_btree_remove(size_tree, rs);
 }
 
-/* ARGSUSED */
 void
 rt_btree_vacate(range_tree_t *rt, void *arg)
 {
diff --git a/module/zfs/sa.c b/module/zfs/sa.c
index 2604a7513e..b69b0c68f1 100644
--- a/module/zfs/sa.c
+++ b/module/zfs/sa.c
@@ -212,20 +212,20 @@ sa_attr_type_t sa_dummy_zpl_layout[] = { 0 };
 static int sa_legacy_attr_count = ARRAY_SIZE(sa_legacy_attrs);
 static kmem_cache_t *sa_cache = NULL;
 
-/*ARGSUSED*/
 static int
 sa_cache_constructor(void *buf, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	sa_handle_t *hdl = buf;
 
 	mutex_init(&hdl->sa_lock, NULL, MUTEX_DEFAULT, NULL);
 	return (0);
 }
 
-/*ARGSUSED*/
 static void
 sa_cache_destructor(void *buf, void *unused)
 {
+	(void) unused;
 	sa_handle_t *hdl = buf;
 	mutex_destroy(&hdl->sa_lock);
 }
@@ -1218,11 +1218,11 @@ sa_attr_iter(objset_t *os, sa_hdr_phys_t *hdr, dmu_object_type_t type,
 	}
 }
 
-/*ARGSUSED*/
 static void
 sa_byteswap_cb(void *hdr, void *attr_addr, sa_attr_type_t attr,
     uint16_t length, int length_idx, boolean_t variable_length, void *userp)
 {
+	(void) hdr, (void) length_idx, (void) variable_length;
 	sa_handle_t *hdl = userp;
 	sa_os_t *sa = hdl->sa_os->os_sa;
 
@@ -1309,10 +1309,10 @@ sa_build_index(sa_handle_t *hdl, sa_buf_type_t buftype)
 	return (0);
 }
 
-/*ARGSUSED*/
 static void
 sa_evict_sync(void *dbu)
 {
+	(void) dbu;
 	panic("evicting sa dbuf\n");
 }
 
diff --git a/module/zfs/sha256.c b/module/zfs/sha256.c
index d297768ead..c5b033cf01 100644
--- a/module/zfs/sha256.c
+++ b/module/zfs/sha256.c
@@ -41,11 +41,11 @@ sha_incremental(void *buf, size_t size, void *arg)
 	return (0);
 }
 
-/*ARGSUSED*/
 void
 abd_checksum_SHA256(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	int ret;
 	SHA2_CTX ctx;
 	zio_cksum_t tmp;
@@ -78,11 +78,11 @@ bswap:
 	zcp->zc_word[3] = BE_64(tmp.zc_word[3]);
 }
 
-/*ARGSUSED*/
 void
 abd_checksum_SHA512_native(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	SHA2_CTX	ctx;
 
 	SHA2Init(SHA512_256, &ctx);
@@ -90,7 +90,6 @@ abd_checksum_SHA512_native(abd_t *abd, uint64_t size,
 	SHA2Final(zcp, &ctx);
 }
 
-/*ARGSUSED*/
 void
 abd_checksum_SHA512_byteswap(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index 896277c883..3c0316990b 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -840,7 +840,6 @@ spa_prop_clear_bootfs(spa_t *spa, uint64_t dsobj, dmu_tx_t *tx)
 	}
 }
 
-/*ARGSUSED*/
 static int
 spa_change_guid_check(void *arg, dmu_tx_t *tx)
 {
@@ -2286,11 +2285,12 @@ int spa_load_verify_shift = 4;
 int spa_load_verify_metadata = B_TRUE;
 int spa_load_verify_data = B_TRUE;
 
-/*ARGSUSED*/
 static int
 spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
 {
+	(void) zilog, (void) dnp;
+
 	if (zb->zb_level == ZB_DNODE_LEVEL || BP_IS_HOLE(bp) ||
 	    BP_IS_EMBEDDED(bp) || BP_IS_REDACTED(bp))
 		return (0);
@@ -2322,10 +2322,11 @@ spa_load_verify_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 verify_dataset_name_len(dsl_pool_t *dp, dsl_dataset_t *ds, void *arg)
 {
+	(void) dp, (void) arg;
+
 	if (dsl_dataset_namelen(ds) >= ZFS_MAX_DATASET_NAME_LEN)
 		return (SET_ERROR(ENAMETOOLONG));
 
@@ -2455,10 +2456,10 @@ spa_livelist_delete_check(spa_t *spa)
 	return (spa->spa_livelists_to_delete != 0);
 }
 
-/* ARGSUSED */
 static boolean_t
 spa_livelist_delete_cb_check(void *arg, zthr_t *z)
 {
+	(void) z;
 	spa_t *spa = arg;
 	return (spa_livelist_delete_check(spa));
 }
@@ -2550,7 +2551,6 @@ livelist_delete_sync(void *arg, dmu_tx_t *tx)
  * be freed. Then, call a synctask which performs the actual frees and updates
  * the pool-wide livelist data.
  */
-/* ARGSUSED */
 static void
 spa_livelist_delete_cb(void *arg, zthr_t *z)
 {
@@ -2796,7 +2796,6 @@ spa_livelist_condense_cb(void *arg, zthr_t *t)
 		zfs_livelist_condense_zthr_cancel++;
 }
 
-/* ARGSUSED */
 /*
  * Check that there is something to condense but that a condense is not
  * already in progress and that condensing has not been cancelled.
@@ -2804,6 +2803,7 @@ spa_livelist_condense_cb(void *arg, zthr_t *t)
 static boolean_t
 spa_livelist_condense_cb_check(void *arg, zthr_t *z)
 {
+	(void) z;
 	spa_t *spa = arg;
 	if ((spa->spa_to_condense.ds != NULL) &&
 	    (spa->spa_to_condense.syncing == B_FALSE) &&
@@ -9465,6 +9465,7 @@ spa_upgrade(spa_t *spa, uint64_t version)
 static boolean_t
 spa_has_aux_vdev(spa_t *spa, uint64_t guid, spa_aux_vdev_t *sav)
 {
+	(void) spa;
 	int i;
 	uint64_t vdev_guid;
 
@@ -9828,6 +9829,8 @@ spa_event_create(spa_t *spa, vdev_t *vd, nvlist_t *hist_nvl, const char *name)
 		ev = kmem_alloc(sizeof (sysevent_t), KM_SLEEP);
 		ev->resource = resource;
 	}
+#else
+	(void) spa, (void) vd, (void) hist_nvl, (void) name;
 #endif
 	return (ev);
 }
@@ -9840,6 +9843,8 @@ spa_event_post(sysevent_t *ev)
 		zfs_zevent_post(ev->resource, NULL, zfs_zevent_post_cb);
 		kmem_free(ev, sizeof (*ev));
 	}
+#else
+	(void) ev;
 #endif
 }
 
diff --git a/module/zfs/spa_checkpoint.c b/module/zfs/spa_checkpoint.c
index 09f6299685..ddcdb68010 100644
--- a/module/zfs/spa_checkpoint.c
+++ b/module/zfs/spa_checkpoint.c
@@ -380,10 +380,10 @@ spa_checkpoint_discard_is_done(spa_t *spa)
 	return (B_TRUE);
 }
 
-/* ARGSUSED */
 boolean_t
 spa_checkpoint_discard_thread_check(void *arg, zthr_t *zthr)
 {
+	(void) zthr;
 	spa_t *spa = arg;
 
 	if (!spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT))
@@ -450,10 +450,10 @@ spa_checkpoint_discard_thread(void *arg, zthr_t *zthr)
 }
 
 
-/* ARGSUSED */
 static int
 spa_checkpoint_check(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 
 	if (!spa_feature_is_enabled(spa, SPA_FEATURE_POOL_CHECKPOINT))
@@ -474,10 +474,10 @@ spa_checkpoint_check(void *arg, dmu_tx_t *tx)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 spa_checkpoint_sync(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	dsl_pool_t *dp = dmu_tx_pool(tx);
 	spa_t *spa = dp->dp_spa;
 	uberblock_t checkpoint = spa->spa_ubsync;
@@ -571,10 +571,10 @@ spa_checkpoint(const char *pool)
 	return (error);
 }
 
-/* ARGSUSED */
 static int
 spa_checkpoint_discard_check(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 
 	if (!spa_feature_is_active(spa, SPA_FEATURE_POOL_CHECKPOINT))
@@ -589,10 +589,10 @@ spa_checkpoint_discard_check(void *arg, dmu_tx_t *tx)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 spa_checkpoint_discard_sync(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 
 	VERIFY0(zap_remove(spa_meta_objset(spa), DMU_POOL_DIRECTORY_OBJECT,
diff --git a/module/zfs/spa_errlog.c b/module/zfs/spa_errlog.c
index fa5120eb61..c6b28ea7d1 100644
--- a/module/zfs/spa_errlog.c
+++ b/module/zfs/spa_errlog.c
@@ -252,6 +252,8 @@ spa_get_errlog(spa_t *spa, void *uaddr, size_t *count)
 	mutex_exit(&spa->spa_errlist_lock);
 
 	mutex_exit(&spa->spa_errlog_lock);
+#else
+	(void) spa, (void) uaddr, (void) count;
 #endif
 
 	return (ret);
diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c
index 3f74631983..6ab602debc 100644
--- a/module/zfs/spa_misc.c
+++ b/module/zfs/spa_misc.c
@@ -495,6 +495,7 @@ spa_config_tryenter(spa_t *spa, int locks, void *tag, krw_t rw)
 void
 spa_config_enter(spa_t *spa, int locks, const void *tag, krw_t rw)
 {
+	(void) tag;
 	int wlocks_held = 0;
 
 	ASSERT3U(SCL_LOCKS, <, sizeof (wlocks_held) * NBBY);
@@ -528,6 +529,7 @@ spa_config_enter(spa_t *spa, int locks, const void *tag, krw_t rw)
 void
 spa_config_exit(spa_t *spa, int locks, const void *tag)
 {
+	(void) tag;
 	for (int i = SCL_LOCKS - 1; i >= 0; i--) {
 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
 		if (!(locks & (1 << i)))
diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index 5784bd2a09..fc914b239f 100644
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -263,11 +263,12 @@ vdev_get_mg(vdev_t *vd, metaslab_class_t *mc)
 		return (vd->vdev_mg);
 }
 
-/* ARGSUSED */
 void
 vdev_default_xlate(vdev_t *vd, const range_seg64_t *logical_rs,
     range_seg64_t *physical_rs, range_seg64_t *remain_rs)
 {
+	(void) vd, (void) remain_rs;
+
 	physical_rs->rs_start = logical_rs->rs_start;
 	physical_rs->rs_end = logical_rs->rs_end;
 }
@@ -1778,6 +1779,7 @@ vdev_uses_zvols(vdev_t *vd)
 static boolean_t
 vdev_default_open_children_func(vdev_t *vd)
 {
+	(void) vd;
 	return (B_TRUE);
 }
 
@@ -2859,6 +2861,8 @@ boolean_t
 vdev_default_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize,
     uint64_t phys_birth)
 {
+	(void) dva, (void) psize;
+
 	/* Set by sequential resilver. */
 	if (phys_birth == TXG_UNKNOWN)
 		return (B_TRUE);
@@ -4308,6 +4312,8 @@ vdev_get_child_stat(vdev_t *cvd, vdev_stat_t *vs, vdev_stat_t *cvs)
 static void
 vdev_get_child_stat_ex(vdev_t *cvd, vdev_stat_ex_t *vsx, vdev_stat_ex_t *cvsx)
 {
+	(void) cvd;
+
 	int t, b;
 	for (t = 0; t < ZIO_TYPES; t++) {
 		for (b = 0; b < ARRAY_SIZE(vsx->vsx_disk_histo[0]); b++)
@@ -4743,6 +4749,7 @@ void
 vdev_space_update(vdev_t *vd, int64_t alloc_delta, int64_t defer_delta,
     int64_t space_delta)
 {
+	(void) defer_delta;
 	int64_t dspace_delta;
 	spa_t *spa = vd->vdev_spa;
 	vdev_t *rvd = spa->spa_root_vdev;
diff --git a/module/zfs/vdev_draid.c b/module/zfs/vdev_draid.c
index 9c222feb9f..eacdcc5261 100644
--- a/module/zfs/vdev_draid.c
+++ b/module/zfs/vdev_draid.c
@@ -2154,6 +2154,7 @@ vdev_draid_config_generate(vdev_t *vd, nvlist_t *nv)
 static int
 vdev_draid_init(spa_t *spa, nvlist_t *nv, void **tsd)
 {
+	(void) spa;
 	uint64_t ndata, nparity, nspares, ngroups;
 	int error;
 
@@ -2382,7 +2383,6 @@ vdev_draid_spare_get_child(vdev_t *vd, uint64_t physical_offset)
 	return (cvd);
 }
 
-/* ARGSUSED */
 static void
 vdev_draid_spare_close(vdev_t *vd)
 {
@@ -2641,10 +2641,10 @@ vdev_draid_spare_io_start(zio_t *zio)
 	zio_execute(zio);
 }
 
-/* ARGSUSED */
 static void
 vdev_draid_spare_io_done(zio_t *zio)
 {
+	(void) zio;
 }
 
 /*
diff --git a/module/zfs/vdev_indirect.c b/module/zfs/vdev_indirect.c
index 14ebf55146..8762855d46 100644
--- a/module/zfs/vdev_indirect.c
+++ b/module/zfs/vdev_indirect.c
@@ -637,16 +637,15 @@ spa_condense_indirect_generate_new_mapping(vdev_t *vd,
 	}
 }
 
-/* ARGSUSED */
 static boolean_t
 spa_condense_indirect_thread_check(void *arg, zthr_t *zthr)
 {
+	(void) zthr;
 	spa_t *spa = arg;
 
 	return (spa->spa_condensing_indirect != NULL);
 }
 
-/* ARGSUSED */
 static void
 spa_condense_indirect_thread(void *arg, zthr_t *zthr)
 {
@@ -941,13 +940,12 @@ vdev_obsolete_counts_are_precise(vdev_t *vd, boolean_t *are_precise)
 	return (error);
 }
 
-/* ARGSUSED */
 static void
 vdev_indirect_close(vdev_t *vd)
 {
+	(void) vd;
 }
 
-/* ARGSUSED */
 static int
 vdev_indirect_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
     uint64_t *logical_ashift, uint64_t *physical_ashift)
diff --git a/module/zfs/vdev_initialize.c b/module/zfs/vdev_initialize.c
index e9156c32f3..6ffd0d618f 100644
--- a/module/zfs/vdev_initialize.c
+++ b/module/zfs/vdev_initialize.c
@@ -255,10 +255,11 @@ vdev_initialize_write(vdev_t *vd, uint64_t start, uint64_t size, abd_t *data)
  * divisible by sizeof (uint64_t), and buf must be 8-byte aligned. The ABD
  * allocation will guarantee these for us.
  */
-/* ARGSUSED */
 static int
 vdev_initialize_block_fill(void *buf, size_t len, void *unused)
 {
+	(void) unused;
+
 	ASSERT0(len % sizeof (uint64_t));
 #ifdef _ILP32
 	for (uint64_t i = 0; i < len; i += sizeof (uint32_t)) {
@@ -624,6 +625,7 @@ vdev_initialize_stop_wait_impl(vdev_t *vd)
 void
 vdev_initialize_stop_wait(spa_t *spa, list_t *vd_list)
 {
+	(void) spa;
 	vdev_t *vd;
 
 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
diff --git a/module/zfs/vdev_mirror.c b/module/zfs/vdev_mirror.c
index 5eb3310469..45b744b2ec 100644
--- a/module/zfs/vdev_mirror.c
+++ b/module/zfs/vdev_mirror.c
@@ -880,6 +880,8 @@ static uint64_t
 vdev_mirror_rebuild_asize(vdev_t *vd, uint64_t start, uint64_t asize,
     uint64_t max_segment)
 {
+	(void) start;
+
 	uint64_t psize = MIN(P2ROUNDUP(max_segment, 1 << vd->vdev_ashift),
 	    SPA_MAXBLOCKSIZE);
 
diff --git a/module/zfs/vdev_missing.c b/module/zfs/vdev_missing.c
index e9145fd012..505df23c1f 100644
--- a/module/zfs/vdev_missing.c
+++ b/module/zfs/vdev_missing.c
@@ -42,7 +42,6 @@
 #include <sys/fs/zfs.h>
 #include <sys/zio.h>
 
-/* ARGSUSED */
 static int
 vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
     uint64_t *ashift, uint64_t *pshift)
@@ -53,6 +52,7 @@ vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
 	 * VDEV_AUX_BAD_GUID_SUM.  So we pretend to succeed, knowing that we
 	 * will fail the GUID sum check before ever trying to open the pool.
 	 */
+	(void) vd;
 	*psize = 0;
 	*max_psize = 0;
 	*ashift = 0;
@@ -60,13 +60,12 @@ vdev_missing_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 vdev_missing_close(vdev_t *vd)
 {
+	(void) vd;
 }
 
-/* ARGSUSED */
 static void
 vdev_missing_io_start(zio_t *zio)
 {
@@ -74,10 +73,10 @@ vdev_missing_io_start(zio_t *zio)
 	zio_execute(zio);
 }
 
-/* ARGSUSED */
 static void
 vdev_missing_io_done(zio_t *zio)
 {
+	(void) zio;
 }
 
 vdev_ops_t vdev_missing_ops = {
diff --git a/module/zfs/vdev_raidz.c b/module/zfs/vdev_raidz.c
index 7e7202ec1e..063570f2ee 100644
--- a/module/zfs/vdev_raidz.c
+++ b/module/zfs/vdev_raidz.c
@@ -648,10 +648,10 @@ vdev_raidz_generate_parity(raidz_map_t *rm)
 	}
 }
 
-/* ARGSUSED */
 static int
 vdev_raidz_reconst_p_func(void *dbuf, void *sbuf, size_t size, void *private)
 {
+	(void) private;
 	uint64_t *dst = dbuf;
 	uint64_t *src = sbuf;
 	int cnt = size / sizeof (src[0]);
@@ -663,11 +663,11 @@ vdev_raidz_reconst_p_func(void *dbuf, void *sbuf, size_t size, void *private)
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 vdev_raidz_reconst_q_pre_func(void *dbuf, void *sbuf, size_t size,
     void *private)
 {
+	(void) private;
 	uint64_t *dst = dbuf;
 	uint64_t *src = sbuf;
 	uint64_t mask;
@@ -681,10 +681,10 @@ vdev_raidz_reconst_q_pre_func(void *dbuf, void *sbuf, size_t size,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 vdev_raidz_reconst_q_pre_tail_func(void *buf, size_t size, void *private)
 {
+	(void) private;
 	uint64_t *dst = buf;
 	uint64_t mask;
 	int cnt = size / sizeof (dst[0]);
@@ -2496,6 +2496,8 @@ static void
 vdev_raidz_xlate(vdev_t *cvd, const range_seg64_t *logical_rs,
     range_seg64_t *physical_rs, range_seg64_t *remain_rs)
 {
+	(void) remain_rs;
+
 	vdev_t *raidvd = cvd->vdev_parent;
 	ASSERT(raidvd->vdev_ops == &vdev_raidz_ops);
 
diff --git a/module/zfs/vdev_removal.c b/module/zfs/vdev_removal.c
index 482b5bb0ba..2a3ee90fe0 100644
--- a/module/zfs/vdev_removal.c
+++ b/module/zfs/vdev_removal.c
@@ -1820,10 +1820,10 @@ vdev_prop_allocating_off(vdev_t *vd)
 	return (allocating == 0);
 }
 
-/* ARGSUSED */
 static int
 spa_vdev_remove_cancel_check(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 
 	if (spa->spa_vdev_removal == NULL)
@@ -1835,10 +1835,10 @@ spa_vdev_remove_cancel_check(void *arg, dmu_tx_t *tx)
  * Cancel a removal by freeing all entries from the partial mapping
  * and marking the vdev as no longer being removing.
  */
-/* ARGSUSED */
 static void
 spa_vdev_remove_cancel_sync(void *arg, dmu_tx_t *tx)
 {
+	(void) arg;
 	spa_t *spa = dmu_tx_pool(tx)->dp_spa;
 	spa_vdev_removal_t *svr = spa->spa_vdev_removal;
 	vdev_t *vd = vdev_lookup_top(spa, svr->svr_vdev_id);
diff --git a/module/zfs/vdev_trim.c b/module/zfs/vdev_trim.c
index deea7fedd7..2bae33b2b5 100644
--- a/module/zfs/vdev_trim.c
+++ b/module/zfs/vdev_trim.c
@@ -1003,6 +1003,7 @@ vdev_trim_stop_wait_impl(vdev_t *vd)
 void
 vdev_trim_stop_wait(spa_t *spa, list_t *vd_list)
 {
+	(void) spa;
 	vdev_t *vd;
 
 	ASSERT(MUTEX_HELD(&spa_namespace_lock));
diff --git a/module/zfs/zcp.c b/module/zfs/zcp.c
index f724b44baf..f200b928bc 100644
--- a/module/zfs/zcp.c
+++ b/module/zfs/zcp.c
@@ -769,10 +769,10 @@ zcp_lua_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
 	}
 }
 
-/* ARGSUSED */
 static void
 zcp_lua_counthook(lua_State *state, lua_Debug *ar)
 {
+	(void) ar;
 	lua_getfield(state, LUA_REGISTRYINDEX, ZCP_RUN_INFO_KEY);
 	zcp_run_info_t *ri = lua_touserdata(state, -1);
 
@@ -974,10 +974,10 @@ zcp_pool_error(zcp_run_info_t *ri, const char *poolname)
  * The txg_wait_synced_sig will continue to wait for the txg to complete
  * after calling this callback.
  */
-/* ARGSUSED */
 static void
 zcp_eval_sig(void *arg, dmu_tx_t *tx)
 {
+	(void) tx;
 	zcp_run_info_t *ri = arg;
 
 	ri->zri_canceled = B_TRUE;
diff --git a/module/zfs/zcp_synctask.c b/module/zfs/zcp_synctask.c
index c6ade59b9c..bfcdbcf9c2 100644
--- a/module/zfs/zcp_synctask.c
+++ b/module/zfs/zcp_synctask.c
@@ -129,10 +129,10 @@ static zcp_synctask_info_t zcp_synctask_destroy_info = {
 	.blocks_modified = 0
 };
 
-/* ARGSUSED */
 static int
 zcp_synctask_destroy(lua_State *state, boolean_t sync, nvlist_t *err_details)
 {
+	(void) err_details;
 	int err;
 	const char *dsname = lua_tostring(state, 1);
 
@@ -251,10 +251,10 @@ static zcp_synctask_info_t zcp_synctask_snapshot_info = {
 	.blocks_modified = 3
 };
 
-/* ARGSUSED */
 static int
 zcp_synctask_snapshot(lua_State *state, boolean_t sync, nvlist_t *err_details)
 {
+	(void) err_details;
 	int err;
 	dsl_dataset_snapshot_arg_t ddsa = { 0 };
 	const char *dsname = lua_tostring(state, 1);
@@ -354,6 +354,7 @@ static int
 zcp_synctask_inherit_prop(lua_State *state, boolean_t sync,
     nvlist_t *err_details)
 {
+	(void) err_details;
 	int err;
 	zcp_inherit_prop_arg_t zipa = { 0 };
 	dsl_props_set_arg_t *dpsa = &zipa.zipa_dpsa;
@@ -396,10 +397,10 @@ static zcp_synctask_info_t zcp_synctask_bookmark_info = {
 	.blocks_modified = 1,
 };
 
-/* ARGSUSED */
 static int
 zcp_synctask_bookmark(lua_State *state, boolean_t sync, nvlist_t *err_details)
 {
+	(void) err_details;
 	int err;
 	const char *source = lua_tostring(state, 1);
 	const char *new = lua_tostring(state, 2);
@@ -443,6 +444,7 @@ static zcp_synctask_info_t zcp_synctask_set_prop_info = {
 static int
 zcp_synctask_set_prop(lua_State *state, boolean_t sync, nvlist_t *err_details)
 {
+	(void) err_details;
 	int err;
 	zcp_set_prop_arg_t args = { 0 };
 
diff --git a/module/zfs/zfs_fm.c b/module/zfs/zfs_fm.c
index 007f31b4e7..87f793cb4e 100644
--- a/module/zfs/zfs_fm.c
+++ b/module/zfs/zfs_fm.c
@@ -59,7 +59,7 @@
  * read I/Os, there  are basically three 'types' of I/O, which form a roughly
  * layered diagram:
  *
- *      +---------------+
+ * 	+---------------+
  * 	| Aggregate I/O |	No associated logical data or device
  * 	+---------------+
  *              |
@@ -205,7 +205,6 @@ static void zfs_ereport_schedule_cleaner(void);
 /*
  * background task to clean stale recent event nodes.
  */
-/*ARGSUSED*/
 static void
 zfs_ereport_cleaner(void *arg)
 {
@@ -992,10 +991,10 @@ annotate_ecksum(nvlist_t *ereport, zio_bad_cksum_t *info,
 	return (eip);
 }
 #else
-/*ARGSUSED*/
 void
 zfs_ereport_clear(spa_t *spa, vdev_t *vd)
 {
+	(void) spa, (void) vd;
 }
 #endif
 
@@ -1072,6 +1071,8 @@ zfs_ereport_is_valid(const char *subclass, spa_t *spa, vdev_t *vd, zio_t *zio)
 	    (zio != NULL) && (!zio->io_timestamp)) {
 		return (B_FALSE);
 	}
+#else
+	(void) subclass, (void) spa, (void) vd, (void) zio;
 #endif
 	return (B_TRUE);
 }
@@ -1112,6 +1113,9 @@ zfs_ereport_post(const char *subclass, spa_t *spa, vdev_t *vd,
 
 	/* Cleanup is handled by the callback function */
 	rc = zfs_zevent_post(ereport, detector, zfs_zevent_post_cb);
+#else
+	(void) subclass, (void) spa, (void) vd, (void) zb, (void) zio,
+	    (void) state;
 #endif
 	return (rc);
 }
@@ -1141,6 +1145,8 @@ zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, const zbookmark_phys_t *zb,
 
 	if (zfs_is_ratelimiting_event(FM_EREPORT_ZFS_CHECKSUM, vd))
 		return (SET_ERROR(EBUSY));
+#else
+	(void) zb, (void) offset;
 #endif
 
 	report = kmem_zalloc(sizeof (*report), KM_SLEEP);
@@ -1193,6 +1199,9 @@ zfs_ereport_finish_checksum(zio_cksum_report_t *report, const abd_t *good_data,
 	report->zcr_ereport = report->zcr_detector = NULL;
 	if (info != NULL)
 		kmem_free(info, sizeof (*info));
+#else
+	(void) report, (void) good_data, (void) bad_data,
+	    (void) drop_if_identical;
 #endif
 }
 
@@ -1257,6 +1266,9 @@ zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd, const zbookmark_phys_t *zb,
 		rc = zfs_zevent_post(ereport, detector, zfs_zevent_post_cb);
 		kmem_free(info, sizeof (*info));
 	}
+#else
+	(void) spa, (void) vd, (void) zb, (void) zio, (void) offset,
+	    (void) length, (void) good_data, (void) bad_data, (void) zbc;
 #endif
 	return (rc);
 }
@@ -1321,7 +1333,8 @@ zfs_event_create(spa_t *spa, vdev_t *vd, const char *type, const char *name,
 		while ((elem = nvlist_next_nvpair(aux, elem)) != NULL)
 			(void) nvlist_add_nvpair(resource, elem);
 	}
-
+#else
+	(void) spa, (void) vd, (void) type, (void) name, (void) aux;
 #endif
 	return (resource);
 }
@@ -1336,6 +1349,8 @@ zfs_post_common(spa_t *spa, vdev_t *vd, const char *type, const char *name,
 	resource = zfs_event_create(spa, vd, type, name, aux);
 	if (resource)
 		zfs_zevent_post(resource, NULL, zfs_zevent_post_cb);
+#else
+	(void) spa, (void) vd, (void) type, (void) name, (void) aux;
 #endif
 }
 
@@ -1399,6 +1414,8 @@ zfs_post_state_change(spa_t *spa, vdev_t *vd, uint64_t laststate)
 
 	if (aux)
 		fm_nvlist_destroy(aux, FM_NVA_FREE);
+#else
+	(void) spa, (void) vd, (void) laststate;
 #endif
 }
 
diff --git a/module/zfs/zil.c b/module/zfs/zil.c
index 640e805d09..b9f177daee 100644
--- a/module/zfs/zil.c
+++ b/module/zfs/zil.c
@@ -432,11 +432,11 @@ done:
 	return (error);
 }
 
-/* ARGSUSED */
 static int
 zil_clear_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx,
     uint64_t first_txg)
 {
+	(void) tx;
 	ASSERT(!BP_IS_HOLE(bp));
 
 	/*
@@ -455,11 +455,11 @@ zil_clear_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 zil_noop_log_record(zilog_t *zilog, const lr_t *lrc, void *tx,
     uint64_t first_txg)
 {
+	(void) zilog, (void) lrc, (void) tx, (void) first_txg;
 	return (0);
 }
 
@@ -507,11 +507,12 @@ zil_claim_log_record(zilog_t *zilog, const lr_t *lrc, void *tx,
 	return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
 }
 
-/* ARGSUSED */
 static int
 zil_free_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx,
     uint64_t claim_txg)
 {
+	(void) claim_txg;
+
 	zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
 
 	return (0);
@@ -911,10 +912,10 @@ zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg)
  * Checksum errors are ok as they indicate the end of the chain.
  * Any other error (no device or read failure) returns an error.
  */
-/* ARGSUSED */
 int
 zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx)
 {
+	(void) dp;
 	zilog_t *zilog;
 	objset_t *os;
 	blkptr_t *bp;
@@ -3127,10 +3128,10 @@ zil_sync(zilog_t *zilog, dmu_tx_t *tx)
 	mutex_exit(&zilog->zl_lock);
 }
 
-/* ARGSUSED */
 static int
 zil_lwb_cons(void *vbuf, void *unused, int kmflag)
 {
+	(void) unused, (void) kmflag;
 	lwb_t *lwb = vbuf;
 	list_create(&lwb->lwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node));
 	list_create(&lwb->lwb_waiters, sizeof (zil_commit_waiter_t),
@@ -3141,10 +3142,10 @@ zil_lwb_cons(void *vbuf, void *unused, int kmflag)
 	return (0);
 }
 
-/* ARGSUSED */
 static void
 zil_lwb_dest(void *vbuf, void *unused)
 {
+	(void) unused;
 	lwb_t *lwb = vbuf;
 	mutex_destroy(&lwb->lwb_vdev_lock);
 	avl_destroy(&lwb->lwb_vdev_tree);
@@ -3615,10 +3616,11 @@ zil_replay_log_record(zilog_t *zilog, const lr_t *lr, void *zra,
 	return (0);
 }
 
-/* ARGSUSED */
 static int
 zil_incr_blks(zilog_t *zilog, const blkptr_t *bp, void *arg, uint64_t claim_txg)
 {
+	(void) bp, (void) arg, (void) claim_txg;
+
 	zilog->zl_replay_blks++;
 
 	return (0);
@@ -3677,13 +3679,12 @@ zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
 	return (B_FALSE);
 }
 
-/* ARGSUSED */
 int
 zil_reset(const char *osname, void *arg)
 {
-	int error;
+	(void) arg;
 
-	error = zil_suspend(osname, NULL);
+	int error = zil_suspend(osname, NULL);
 	/* EACCES means crypto key not loaded */
 	if ((error == EACCES) || (error == EBUSY))
 		return (SET_ERROR(error));
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 2079a1e0a9..e04be06bf3 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -369,6 +369,7 @@ zio_data_buf_free(void *buf, size_t size)
 static void
 zio_abd_free(void *abd, size_t size)
 {
+	(void) size;
 	abd_free((abd_t *)abd);
 }
 
@@ -1072,6 +1073,7 @@ zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held,
 boolean_t
 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp)
 {
+	(void) bp;
 	uint64_t vdevid = DVA_GET_VDEV(dva);
 
 	if (vdevid >= spa->spa_root_vdev->vdev_children)
@@ -2143,6 +2145,8 @@ zio_execute_stack_check(zio_t *zio)
 	    !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) &&
 	    !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH))
 		return (B_TRUE);
+#else
+	(void) zio;
 #endif /* HAVE_LARGE_STACKS */
 
 	return (B_FALSE);
@@ -2555,11 +2559,12 @@ zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
 	return (zio);
 }
 
-/* ARGSUSED */
 static zio_t *
 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
     uint64_t offset)
 {
+	(void) gn, (void) data, (void) offset;
+
 	zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
 	    ZIO_GANG_CHILD_FLAGS(pio));
 	if (zio == NULL) {
@@ -2569,11 +2574,11 @@ zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
 	return (zio);
 }
 
-/* ARGSUSED */
 static zio_t *
 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
     uint64_t offset)
 {
+	(void) gn, (void) data, (void) offset;
 	return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
 	    NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
 }
@@ -3964,7 +3969,6 @@ zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
 	zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
 }
 
-/*ARGSUSED*/
 void
 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr)
 {
diff --git a/module/zfs/zio_checksum.c b/module/zfs/zio_checksum.c
index e6b5c95889..4dbab68dd7 100644
--- a/module/zfs/zio_checksum.c
+++ b/module/zfs/zio_checksum.c
@@ -91,29 +91,29 @@
  * invocation and passed to the checksum function.
  */
 
-/*ARGSUSED*/
 static void
 abd_checksum_off(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) abd, (void) size, (void) ctx_template;
 	ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
 }
 
-/*ARGSUSED*/
 static void
 abd_fletcher_2_native(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	fletcher_init(zcp);
 	(void) abd_iterate_func(abd, 0, size,
 	    fletcher_2_incremental_native, zcp);
 }
 
-/*ARGSUSED*/
 static void
 abd_fletcher_2_byteswap(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	fletcher_init(zcp);
 	(void) abd_iterate_func(abd, 0, size,
 	    fletcher_2_incremental_byteswap, zcp);
@@ -127,11 +127,11 @@ abd_fletcher_4_impl(abd_t *abd, uint64_t size, zio_abd_checksum_data_t *acdp)
 	fletcher_4_abd_ops.acf_fini(acdp);
 }
 
-/*ARGSUSED*/
 void
 abd_fletcher_4_native(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	fletcher_4_ctx_t ctx;
 
 	zio_abd_checksum_data_t acd = {
@@ -144,11 +144,11 @@ abd_fletcher_4_native(abd_t *abd, uint64_t size,
 
 }
 
-/*ARGSUSED*/
 void
 abd_fletcher_4_byteswap(abd_t *abd, uint64_t size,
     const void *ctx_template, zio_cksum_t *zcp)
 {
+	(void) ctx_template;
 	fletcher_4_ctx_t ctx;
 
 	zio_abd_checksum_data_t acd = {
diff --git a/module/zfs/zio_compress.c b/module/zfs/zio_compress.c
index 1ff1e76d7f..cded11f4cb 100644
--- a/module/zfs/zio_compress.c
+++ b/module/zfs/zio_compress.c
@@ -74,6 +74,7 @@ uint8_t
 zio_complevel_select(spa_t *spa, enum zio_compress compress, uint8_t child,
     uint8_t parent)
 {
+	(void) spa;
 	uint8_t result;
 
 	if (!ZIO_COMPRESS_HASLEVEL(compress))
@@ -110,10 +111,11 @@ zio_compress_select(spa_t *spa, enum zio_compress child,
 	return (result);
 }
 
-/*ARGSUSED*/
 static int
 zio_compress_zeroed_cb(void *data, size_t len, void *private)
 {
+	(void) private;
+
 	uint64_t *end = (uint64_t *)((char *)data + len);
 	for (uint64_t *word = (uint64_t *)data; word < end; word++)
 		if (*word != 0)