diff --git a/test/core/iomgr/combiner_test.cc b/test/core/iomgr/combiner_test.cc
index c39c3fc8fce..e6e5cdfbd5f 100644
--- a/test/core/iomgr/combiner_test.cc
+++ b/test/core/iomgr/combiner_test.cc
@@ -32,7 +32,7 @@ static void test_no_op(void) {
   GRPC_COMBINER_UNREF(grpc_combiner_create(), "test_no_op");
 }
 
-static void set_event_to_true(void* value, grpc_error* error) {
+static void set_event_to_true(void* value, grpc_error* /*error*/) {
   gpr_event_set(static_cast<gpr_event*>(value), (void*)1);
 }
 
@@ -63,7 +63,7 @@ typedef struct {
   size_t value;
 } ex_args;
 
-static void check_one(void* a, grpc_error* error) {
+static void check_one(void* a, grpc_error* /*error*/) {
   ex_args* args = static_cast<ex_args*>(a);
   GPR_ASSERT(*args->ctr == args->value - 1);
   *args->ctr = args->value;
@@ -117,11 +117,11 @@ static void test_execute_many(void) {
 
 static gpr_event got_in_finally;
 
-static void in_finally(void* arg, grpc_error* error) {
+static void in_finally(void* /*arg*/, grpc_error* /*error*/) {
   gpr_event_set(&got_in_finally, (void*)1);
 }
 
-static void add_finally(void* arg, grpc_error* error) {
+static void add_finally(void* arg, grpc_error* /*error*/) {
   GRPC_CLOSURE_SCHED(GRPC_CLOSURE_CREATE(in_finally, arg,
                                          grpc_combiner_finally_scheduler(
                                              static_cast<grpc_combiner*>(arg))),
diff --git a/test/core/iomgr/endpoint_pair_test.cc b/test/core/iomgr/endpoint_pair_test.cc
index 3ddbe7f2fc0..40d676abc32 100644
--- a/test/core/iomgr/endpoint_pair_test.cc
+++ b/test/core/iomgr/endpoint_pair_test.cc
@@ -54,7 +54,7 @@ static grpc_endpoint_test_config configs[] = {
     {"tcp/tcp_socketpair", create_fixture_endpoint_pair, clean_up},
 };
 
-static void destroy_pollset(void* p, grpc_error* error) {
+static void destroy_pollset(void* p, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
 }
 
diff --git a/test/core/iomgr/ev_epollex_linux_test.cc b/test/core/iomgr/ev_epollex_linux_test.cc
index faa3ef344a1..08a28e0b515 100644
--- a/test/core/iomgr/ev_epollex_linux_test.cc
+++ b/test/core/iomgr/ev_epollex_linux_test.cc
@@ -27,7 +27,7 @@
 
 #include "test/core/util/test_config.h"
 
-static void pollset_destroy(void* ps, grpc_error* error) {
+static void pollset_destroy(void* ps, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(ps));
   gpr_free(ps);
 }
diff --git a/test/core/iomgr/fd_posix_test.cc b/test/core/iomgr/fd_posix_test.cc
index cf5ffc63543..79afb49066a 100644
--- a/test/core/iomgr/fd_posix_test.cc
+++ b/test/core/iomgr/fd_posix_test.cc
@@ -82,7 +82,7 @@ static void create_test_socket(int port, int* socket_fd,
 }
 
 /* Dummy gRPC callback */
-void no_op_cb(void* arg, int success) {}
+void no_op_cb(void* /*arg*/, int /*success*/) {}
 
 /* =======An upload server to test notify_on_read===========
    The server simply reads and counts a stream of bytes. */
@@ -112,7 +112,7 @@ typedef struct {
 /* Called when an upload session can be safely shutdown.
    Close session FD and start to shutdown listen FD. */
 static void session_shutdown_cb(void* arg, /*session */
-                                bool success) {
+                                bool /*success*/) {
   session* se = static_cast<session*>(arg);
   server* sv = se->sv;
   grpc_fd_orphan(se->em_fd, nullptr, nullptr, "a");
@@ -168,7 +168,7 @@ static void session_read_cb(void* arg, /*session */
 
 /* Called when the listen FD can be safely shutdown.
    Close listen FD and signal that server can be shutdown. */
-static void listen_shutdown_cb(void* arg /*server */, int success) {
+static void listen_shutdown_cb(void* arg /*server*/, int /*success*/) {
   server* sv = static_cast<server*>(arg);
 
   grpc_fd_orphan(sv->em_fd, nullptr, nullptr, "b");
@@ -287,7 +287,7 @@ static void client_init(client* cl) {
 }
 
 /* Called when a client upload session is ready to shutdown. */
-static void client_session_shutdown_cb(void* arg /*client */, int success) {
+static void client_session_shutdown_cb(void* arg /*client*/, int /*success*/) {
   client* cl = static_cast<client*>(arg);
   grpc_fd_orphan(cl->em_fd, nullptr, nullptr, "c");
   cl->done = 1;
@@ -401,10 +401,10 @@ typedef struct fd_change_data {
 
 void init_change_data(fd_change_data* fdc) { fdc->cb_that_ran = nullptr; }
 
-void destroy_change_data(fd_change_data* fdc) {}
+void destroy_change_data(fd_change_data* /*fdc*/) {}
 
 static void first_read_callback(void* arg /* fd_change_data */,
-                                grpc_error* error) {
+                                grpc_error* /*error*/) {
   fd_change_data* fdc = static_cast<fd_change_data*>(arg);
 
   gpr_mu_lock(g_mu);
@@ -415,7 +415,7 @@ static void first_read_callback(void* arg /* fd_change_data */,
 }
 
 static void second_read_callback(void* arg /* fd_change_data */,
-                                 grpc_error* error) {
+                                 grpc_error* /*error*/) {
   fd_change_data* fdc = static_cast<fd_change_data*>(arg);
 
   gpr_mu_lock(g_mu);
@@ -509,7 +509,7 @@ static void test_grpc_fd_change(void) {
   close(sv[1]);
 }
 
-static void destroy_pollset(void* p, grpc_error* error) {
+static void destroy_pollset(void* p, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
 }
 
diff --git a/test/core/iomgr/resolve_address_posix_test.cc b/test/core/iomgr/resolve_address_posix_test.cc
index 112d7c2791b..4247bfa5950 100644
--- a/test/core/iomgr/resolve_address_posix_test.cc
+++ b/test/core/iomgr/resolve_address_posix_test.cc
@@ -53,7 +53,7 @@ typedef struct args_struct {
   grpc_pollset_set* pollset_set;
 } args_struct;
 
-static void do_nothing(void* arg, grpc_error* error) {}
+static void do_nothing(void* /*arg*/, grpc_error* /*error*/) {}
 
 void args_init(args_struct* args) {
   gpr_event_init(&args->ev);
diff --git a/test/core/iomgr/resolve_address_test.cc b/test/core/iomgr/resolve_address_test.cc
index cbc03485d7f..48d3f8eb105 100644
--- a/test/core/iomgr/resolve_address_test.cc
+++ b/test/core/iomgr/resolve_address_test.cc
@@ -47,7 +47,7 @@ typedef struct args_struct {
   grpc_pollset_set* pollset_set;
 } args_struct;
 
-static void do_nothing(void* arg, grpc_error* error) {}
+static void do_nothing(void* /*arg*/, grpc_error* /*error*/) {}
 
 void args_init(args_struct* args) {
   gpr_event_init(&args->ev);
@@ -310,7 +310,7 @@ typedef struct mock_ipv6_disabled_source_addr_factory {
 } mock_ipv6_disabled_source_addr_factory;
 
 static bool mock_ipv6_disabled_source_addr_factory_get_source_addr(
-    address_sorting_source_addr_factory* factory,
+    address_sorting_source_addr_factory* /*factory*/,
     const address_sorting_address* dest_addr,
     address_sorting_address* source_addr) {
   // Mock lack of IPv6. For IPv4, set the source addr to be the same
diff --git a/test/core/iomgr/resource_quota_test.cc b/test/core/iomgr/resource_quota_test.cc
index 54aaea524fa..27ffd3f9ec9 100644
--- a/test/core/iomgr/resource_quota_test.cc
+++ b/test/core/iomgr/resource_quota_test.cc
@@ -28,7 +28,7 @@
 gpr_mu g_mu;
 gpr_cv g_cv;
 
-static void inc_int_cb(void* a, grpc_error* error) {
+static void inc_int_cb(void* a, grpc_error* /*error*/) {
   gpr_mu_lock(&g_mu);
   ++*static_cast<int*>(a);
   gpr_cv_signal(&g_cv);
@@ -44,7 +44,7 @@ static void assert_counter_becomes(int* ctr, int value) {
   gpr_mu_unlock(&g_mu);
 }
 
-static void set_event_cb(void* a, grpc_error* error) {
+static void set_event_cb(void* a, grpc_error* /*error*/) {
   gpr_event_set(static_cast<gpr_event*>(a), (void*)1);
 }
 grpc_closure* set_event(gpr_event* ev) {
diff --git a/test/core/iomgr/tcp_client_posix_test.cc b/test/core/iomgr/tcp_client_posix_test.cc
index 5cf3530c77a..0896a27f40b 100644
--- a/test/core/iomgr/tcp_client_posix_test.cc
+++ b/test/core/iomgr/tcp_client_posix_test.cc
@@ -60,7 +60,7 @@ static void finish_connection() {
   gpr_mu_unlock(g_mu);
 }
 
-static void must_succeed(void* arg, grpc_error* error) {
+static void must_succeed(void* /*arg*/, grpc_error* error) {
   GPR_ASSERT(g_connecting != nullptr);
   GPR_ASSERT(error == GRPC_ERROR_NONE);
   grpc_endpoint_shutdown(g_connecting, GRPC_ERROR_CREATE_FROM_STATIC_STRING(
@@ -70,7 +70,7 @@ static void must_succeed(void* arg, grpc_error* error) {
   finish_connection();
 }
 
-static void must_fail(void* arg, grpc_error* error) {
+static void must_fail(void* /*arg*/, grpc_error* error) {
   GPR_ASSERT(g_connecting == nullptr);
   GPR_ASSERT(error != GRPC_ERROR_NONE);
   finish_connection();
@@ -185,7 +185,7 @@ void test_fails(void) {
   gpr_mu_unlock(g_mu);
 }
 
-static void destroy_pollset(void* p, grpc_error* error) {
+static void destroy_pollset(void* p, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
 }
 
diff --git a/test/core/iomgr/tcp_posix_test.cc b/test/core/iomgr/tcp_posix_test.cc
index 33a4d973ed3..a202533889d 100644
--- a/test/core/iomgr/tcp_posix_test.cc
+++ b/test/core/iomgr/tcp_posix_test.cc
@@ -472,7 +472,7 @@ static void write_test(size_t num_bytes, size_t slice_size,
   gpr_free(slices);
 }
 
-void on_fd_released(void* arg, grpc_error* errors) {
+void on_fd_released(void* arg, grpc_error* /*errors*/) {
   int* done = static_cast<int*>(arg);
   *done = 1;
   GPR_ASSERT(
@@ -618,7 +618,7 @@ static grpc_endpoint_test_config configs[] = {
     {"tcp/tcp_socketpair", create_fixture_tcp_socketpair, clean_up},
 };
 
-static void destroy_pollset(void* p, grpc_error* error) {
+static void destroy_pollset(void* p, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
 }
 
diff --git a/test/core/iomgr/tcp_server_posix_test.cc b/test/core/iomgr/tcp_server_posix_test.cc
index 81e26b20cd8..0292f771fc9 100644
--- a/test/core/iomgr/tcp_server_posix_test.cc
+++ b/test/core/iomgr/tcp_server_posix_test.cc
@@ -110,7 +110,7 @@ static void on_connect_result_set(on_connect_result* result,
       result->server, acceptor->port_index, acceptor->fd_index);
 }
 
-static void server_weak_ref_shutdown(void* arg, grpc_error* error) {
+static void server_weak_ref_shutdown(void* arg, grpc_error* /*error*/) {
   server_weak_ref* weak_ref = static_cast<server_weak_ref*>(arg);
   weak_ref->server = nullptr;
 }
@@ -144,7 +144,8 @@ static void test_addr_init_str(test_addr* addr) {
   }
 }
 
-static void on_connect(void* arg, grpc_endpoint* tcp, grpc_pollset* pollset,
+static void on_connect(void* /*arg*/, grpc_endpoint* tcp,
+                       grpc_pollset* /*pollset*/,
                        grpc_tcp_server_acceptor* acceptor) {
   grpc_endpoint_shutdown(tcp,
                          GRPC_ERROR_CREATE_FROM_STATIC_STRING("Connected"));
@@ -421,7 +422,7 @@ static void test_connect(size_t num_connects,
   GPR_ASSERT(weak_ref.server == nullptr);
 }
 
-static void destroy_pollset(void* p, grpc_error* error) {
+static void destroy_pollset(void* p, grpc_error* /*error*/) {
   grpc_pollset_destroy(static_cast<grpc_pollset*>(p));
 }