diff --git a/BUILD b/BUILD
index 69b5c320705..955d224574a 100644
--- a/BUILD
+++ b/BUILD
@@ -44,6 +44,7 @@ package(default_visibility = ["//visibility:public"])
 cc_library(
   name = "gpr",
   srcs = [
+    "src/core/support/block_annotate.h",
     "src/core/support/env.h",
     "src/core/support/file.h",
     "src/core/support/murmur_hash.h",
@@ -179,7 +180,6 @@ cc_library(
     "src/core/iomgr/alarm.h",
     "src/core/iomgr/alarm_heap.h",
     "src/core/iomgr/alarm_internal.h",
-    "src/core/iomgr/block_annotate.h",
     "src/core/iomgr/endpoint.h",
     "src/core/iomgr/endpoint_pair.h",
     "src/core/iomgr/fd_posix.h",
@@ -456,7 +456,6 @@ cc_library(
     "src/core/iomgr/alarm.h",
     "src/core/iomgr/alarm_heap.h",
     "src/core/iomgr/alarm_internal.h",
-    "src/core/iomgr/block_annotate.h",
     "src/core/iomgr/endpoint.h",
     "src/core/iomgr/endpoint_pair.h",
     "src/core/iomgr/fd_posix.h",
@@ -1007,6 +1006,7 @@ objc_library(
     "include/grpc/support/tls_msvc.h",
     "include/grpc/support/tls_pthread.h",
     "include/grpc/support/useful.h",
+    "src/core/support/block_annotate.h",
     "src/core/support/env.h",
     "src/core/support/file.h",
     "src/core/support/murmur_hash.h",
@@ -1229,7 +1229,6 @@ objc_library(
     "src/core/iomgr/alarm.h",
     "src/core/iomgr/alarm_heap.h",
     "src/core/iomgr/alarm_internal.h",
-    "src/core/iomgr/block_annotate.h",
     "src/core/iomgr/endpoint.h",
     "src/core/iomgr/endpoint_pair.h",
     "src/core/iomgr/fd_posix.h",
diff --git a/build.yaml b/build.yaml
index 4479ca655cd..a9aba93f322 100644
--- a/build.yaml
+++ b/build.yaml
@@ -55,31 +55,31 @@ filegroups:
     src/core/client_config/uri_parser.h, src/core/compression/message_compress.h,
     src/core/debug/trace.h, src/core/httpcli/format_request.h, src/core/httpcli/httpcli.h,
     src/core/httpcli/parser.h, src/core/iomgr/alarm.h, src/core/iomgr/alarm_heap.h,
-    src/core/iomgr/alarm_internal.h, src/core/iomgr/block_annotate.h, src/core/iomgr/endpoint.h,
-    src/core/iomgr/endpoint_pair.h, src/core/iomgr/fd_posix.h, src/core/iomgr/iocp_windows.h,
-    src/core/iomgr/iomgr.h, src/core/iomgr/iomgr_internal.h, src/core/iomgr/iomgr_posix.h,
-    src/core/iomgr/pollset.h, src/core/iomgr/pollset_posix.h, src/core/iomgr/pollset_set.h,
-    src/core/iomgr/pollset_set_posix.h, src/core/iomgr/pollset_set_windows.h, src/core/iomgr/pollset_windows.h,
-    src/core/iomgr/resolve_address.h, src/core/iomgr/sockaddr.h, src/core/iomgr/sockaddr_posix.h,
-    src/core/iomgr/sockaddr_utils.h, src/core/iomgr/sockaddr_win32.h, src/core/iomgr/socket_utils_posix.h,
-    src/core/iomgr/socket_windows.h, src/core/iomgr/tcp_client.h, src/core/iomgr/tcp_posix.h,
-    src/core/iomgr/tcp_server.h, src/core/iomgr/tcp_windows.h, src/core/iomgr/time_averaged_stats.h,
-    src/core/iomgr/udp_server.h, src/core/iomgr/wakeup_fd_pipe.h, src/core/iomgr/wakeup_fd_posix.h,
-    src/core/json/json.h, src/core/json/json_common.h, src/core/json/json_reader.h,
-    src/core/json/json_writer.h, src/core/profiling/timers.h, src/core/statistics/census_interface.h,
-    src/core/statistics/census_rpc_stats.h, src/core/surface/byte_buffer_queue.h,
-    src/core/surface/call.h, src/core/surface/channel.h, src/core/surface/completion_queue.h,
-    src/core/surface/event_string.h, src/core/surface/init.h, src/core/surface/server.h,
-    src/core/surface/surface_trace.h, src/core/transport/chttp2/alpn.h, src/core/transport/chttp2/bin_encoder.h,
-    src/core/transport/chttp2/frame.h, src/core/transport/chttp2/frame_data.h, src/core/transport/chttp2/frame_goaway.h,
-    src/core/transport/chttp2/frame_ping.h, src/core/transport/chttp2/frame_rst_stream.h,
-    src/core/transport/chttp2/frame_settings.h, src/core/transport/chttp2/frame_window_update.h,
-    src/core/transport/chttp2/hpack_parser.h, src/core/transport/chttp2/hpack_table.h,
-    src/core/transport/chttp2/http2_errors.h, src/core/transport/chttp2/huffsyms.h,
-    src/core/transport/chttp2/incoming_metadata.h, src/core/transport/chttp2/internal.h,
-    src/core/transport/chttp2/status_conversion.h, src/core/transport/chttp2/stream_encoder.h,
-    src/core/transport/chttp2/stream_map.h, src/core/transport/chttp2/timeout_encoding.h,
-    src/core/transport/chttp2/varint.h, src/core/transport/chttp2_transport.h, src/core/transport/connectivity_state.h,
+    src/core/iomgr/alarm_internal.h, src/core/iomgr/endpoint.h, src/core/iomgr/endpoint_pair.h,
+    src/core/iomgr/fd_posix.h, src/core/iomgr/iocp_windows.h, src/core/iomgr/iomgr.h,
+    src/core/iomgr/iomgr_internal.h, src/core/iomgr/iomgr_posix.h, src/core/iomgr/pollset.h,
+    src/core/iomgr/pollset_posix.h, src/core/iomgr/pollset_set.h, src/core/iomgr/pollset_set_posix.h,
+    src/core/iomgr/pollset_set_windows.h, src/core/iomgr/pollset_windows.h, src/core/iomgr/resolve_address.h,
+    src/core/iomgr/sockaddr.h, src/core/iomgr/sockaddr_posix.h, src/core/iomgr/sockaddr_utils.h,
+    src/core/iomgr/sockaddr_win32.h, src/core/iomgr/socket_utils_posix.h, src/core/iomgr/socket_windows.h,
+    src/core/iomgr/tcp_client.h, src/core/iomgr/tcp_posix.h, src/core/iomgr/tcp_server.h,
+    src/core/iomgr/tcp_windows.h, src/core/iomgr/time_averaged_stats.h, src/core/iomgr/udp_server.h,
+    src/core/iomgr/wakeup_fd_pipe.h, src/core/iomgr/wakeup_fd_posix.h, src/core/json/json.h,
+    src/core/json/json_common.h, src/core/json/json_reader.h, src/core/json/json_writer.h,
+    src/core/profiling/timers.h, src/core/statistics/census_interface.h, src/core/statistics/census_rpc_stats.h,
+    src/core/surface/byte_buffer_queue.h, src/core/surface/call.h, src/core/surface/channel.h,
+    src/core/surface/completion_queue.h, src/core/surface/event_string.h, src/core/surface/init.h,
+    src/core/surface/server.h, src/core/surface/surface_trace.h, src/core/transport/chttp2/alpn.h,
+    src/core/transport/chttp2/bin_encoder.h, src/core/transport/chttp2/frame.h, src/core/transport/chttp2/frame_data.h,
+    src/core/transport/chttp2/frame_goaway.h, src/core/transport/chttp2/frame_ping.h,
+    src/core/transport/chttp2/frame_rst_stream.h, src/core/transport/chttp2/frame_settings.h,
+    src/core/transport/chttp2/frame_window_update.h, src/core/transport/chttp2/hpack_parser.h,
+    src/core/transport/chttp2/hpack_table.h, src/core/transport/chttp2/http2_errors.h,
+    src/core/transport/chttp2/huffsyms.h, src/core/transport/chttp2/incoming_metadata.h,
+    src/core/transport/chttp2/internal.h, src/core/transport/chttp2/status_conversion.h,
+    src/core/transport/chttp2/stream_encoder.h, src/core/transport/chttp2/stream_map.h,
+    src/core/transport/chttp2/timeout_encoding.h, src/core/transport/chttp2/varint.h,
+    src/core/transport/chttp2_transport.h, src/core/transport/connectivity_state.h,
     src/core/transport/metadata.h, src/core/transport/stream_op.h, src/core/transport/transport.h,
     src/core/transport/transport_impl.h]
   src: [src/core/census/grpc_context.c, src/core/census/grpc_filter.c, src/core/channel/channel_args.c,
@@ -148,9 +148,9 @@ libs:
     include/grpc/support/sync_posix.h, include/grpc/support/sync_win32.h, include/grpc/support/thd.h,
     include/grpc/support/time.h, include/grpc/support/tls.h, include/grpc/support/tls_gcc.h,
     include/grpc/support/tls_msvc.h, include/grpc/support/tls_pthread.h, include/grpc/support/useful.h]
-  headers: [src/core/support/env.h, src/core/support/file.h, src/core/support/murmur_hash.h,
-    src/core/support/stack_lockfree.h, src/core/support/string.h, src/core/support/string_win32.h,
-    src/core/support/thd_internal.h, src/core/support/time_precise.h]
+  headers: [src/core/support/block_annotate.h, src/core/support/env.h, src/core/support/file.h,
+    src/core/support/murmur_hash.h, src/core/support/stack_lockfree.h, src/core/support/string.h,
+    src/core/support/string_win32.h, src/core/support/thd_internal.h, src/core/support/time_precise.h]
   src: [src/core/support/alloc.c, src/core/support/cmdline.c, src/core/support/cpu_iphone.c,
     src/core/support/cpu_linux.c, src/core/support/cpu_posix.c, src/core/support/cpu_windows.c,
     src/core/support/env_linux.c, src/core/support/env_posix.c, src/core/support/env_win32.c,
diff --git a/gRPC.podspec b/gRPC.podspec
index 38d6b2861f8..a8d586f847c 100644
--- a/gRPC.podspec
+++ b/gRPC.podspec
@@ -61,7 +61,8 @@ Pod::Spec.new do |s|
 
   # Core cross-platform gRPC library, written in C.
   s.subspec 'C-Core' do |ss|
-    ss.source_files = 'src/core/support/env.h',
+    ss.source_files = 'src/core/support/block_annotate.h',
+                      'src/core/support/env.h',
                       'src/core/support/file.h',
                       'src/core/support/murmur_hash.h',
                       'src/core/support/stack_lockfree.h',
@@ -181,7 +182,6 @@ Pod::Spec.new do |s|
                       'src/core/iomgr/alarm.h',
                       'src/core/iomgr/alarm_heap.h',
                       'src/core/iomgr/alarm_internal.h',
-                      'src/core/iomgr/block_annotate.h',
                       'src/core/iomgr/endpoint.h',
                       'src/core/iomgr/endpoint_pair.h',
                       'src/core/iomgr/fd_posix.h',
@@ -406,7 +406,8 @@ Pod::Spec.new do |s|
                       'src/core/census/operation.c',
                       'src/core/census/tracing.c'
 
-    ss.private_header_files = 'src/core/support/env.h',
+    ss.private_header_files = 'src/core/support/block_annotate.h',
+                              'src/core/support/env.h',
                               'src/core/support/file.h',
                               'src/core/support/murmur_hash.h',
                               'src/core/support/stack_lockfree.h',
@@ -462,7 +463,6 @@ Pod::Spec.new do |s|
                               'src/core/iomgr/alarm.h',
                               'src/core/iomgr/alarm_heap.h',
                               'src/core/iomgr/alarm_internal.h',
-                              'src/core/iomgr/block_annotate.h',
                               'src/core/iomgr/endpoint.h',
                               'src/core/iomgr/endpoint_pair.h',
                               'src/core/iomgr/fd_posix.h',
diff --git a/src/core/iomgr/pollset_multipoller_with_epoll.c b/src/core/iomgr/pollset_multipoller_with_epoll.c
index 39746d501b6..65d1517291e 100644
--- a/src/core/iomgr/pollset_multipoller_with_epoll.c
+++ b/src/core/iomgr/pollset_multipoller_with_epoll.c
@@ -41,8 +41,8 @@
 #include <sys/epoll.h>
 #include <unistd.h>
 
-#include "src/core/iomgr/block_annotate.h"
 #include "src/core/iomgr/fd_posix.h"
+#include "src/core/support/block_annotate.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
@@ -181,9 +181,9 @@ static void multipoll_with_epoll_pollset_maybe_work(
   pfds[1].events = POLLIN;
   pfds[1].revents = 0;
 
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   poll_rv = grpc_poll_function(pfds, 2, timeout_ms);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
 
   if (poll_rv < 0) {
     if (errno != EINTR) {
@@ -197,9 +197,9 @@ static void multipoll_with_epoll_pollset_maybe_work(
     }
     if (pfds[1].revents) {
       do {
-        GRPC_IOMGR_START_BLOCKING_REGION;
+        GRPC_SCHEDULING_START_BLOCKING_REGION;
         ep_rv = epoll_wait(h->epoll_fd, ep_ev, GRPC_EPOLL_MAX_EVENTS, 0);
-        GRPC_IOMGR_END_BLOCKING_REGION;
+        GRPC_SCHEDULING_END_BLOCKING_REGION;
         if (ep_rv < 0) {
           if (errno != EINTR) {
             gpr_log(GPR_ERROR, "epoll_wait() failed: %s", strerror(errno));
diff --git a/src/core/iomgr/pollset_multipoller_with_poll_posix.c b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
index 0b12aaca6d3..75bba8214d3 100644
--- a/src/core/iomgr/pollset_multipoller_with_poll_posix.c
+++ b/src/core/iomgr/pollset_multipoller_with_poll_posix.c
@@ -42,9 +42,9 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "src/core/iomgr/block_annotate.h"
 #include "src/core/iomgr/fd_posix.h"
 #include "src/core/iomgr/iomgr_internal.h"
+#include "src/core/support/block_annotate.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/useful.h>
@@ -146,9 +146,9 @@ static void multipoll_with_poll_pollset_maybe_work(
                                                POLLOUT, &watchers[i]);
   }
 
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   r = grpc_poll_function(pfds, pfd_count, timeout);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
 
   for (i = 1; i < pfd_count; i++) {
     grpc_fd_end_poll(&watchers[i], pfds[i].revents & POLLIN,
diff --git a/src/core/iomgr/pollset_posix.c b/src/core/iomgr/pollset_posix.c
index cfdfbcf6065..7d5340140c3 100644
--- a/src/core/iomgr/pollset_posix.c
+++ b/src/core/iomgr/pollset_posix.c
@@ -43,11 +43,11 @@
 #include <unistd.h>
 
 #include "src/core/iomgr/alarm_internal.h"
-#include "src/core/iomgr/block_annotate.h"
 #include "src/core/iomgr/fd_posix.h"
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/socket_utils_posix.h"
 #include "src/core/profiling/timers.h"
+#include "src/core/support/block_annotate.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/thd.h>
@@ -454,9 +454,9 @@ static void basic_pollset_maybe_work(grpc_pollset *pollset,
 
   /* poll fd count (argument 2) is shortened by one if we have no events
      to poll on - such that it only includes the kicker */
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   r = grpc_poll_function(pfd, nfds, timeout);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   GRPC_TIMER_MARK(GRPC_PTAG_POLL_FINISHED, r);
 
   if (fd) {
diff --git a/src/core/iomgr/resolve_address_posix.c b/src/core/iomgr/resolve_address_posix.c
index e7ebe3a2e61..00b7423eab2 100644
--- a/src/core/iomgr/resolve_address_posix.c
+++ b/src/core/iomgr/resolve_address_posix.c
@@ -41,9 +41,9 @@
 #include <sys/un.h>
 #include <string.h>
 
-#include "src/core/iomgr/block_annotate.h"
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/support/block_annotate.h"
 #include "src/core/support/string.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
@@ -104,18 +104,18 @@ grpc_resolved_addresses *grpc_blocking_resolve_address(
   hints.ai_socktype = SOCK_STREAM; /* stream socket */
   hints.ai_flags = AI_PASSIVE;     /* for wildcard IP address */
 
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
 
   if (s != 0) {
     /* Retry if well-known service name is recognized */
     char *svc[][2] = {{"http", "80"}, {"https", "443"}};
     for (i = 0; i < GPR_ARRAY_SIZE(svc); i++) {
       if (strcmp(port, svc[i][0]) == 0) {
-        GRPC_IOMGR_START_BLOCKING_REGION;
+        GRPC_SCHEDULING_START_BLOCKING_REGION;
         s = getaddrinfo(host, svc[i][1], &hints, &result);
-        GRPC_IOMGR_END_BLOCKING_REGION;
+        GRPC_SCHEDULING_END_BLOCKING_REGION;
         break;
       }
     }
diff --git a/src/core/iomgr/resolve_address_windows.c b/src/core/iomgr/resolve_address_windows.c
index e9297a78956..5e63df9f666 100644
--- a/src/core/iomgr/resolve_address_windows.c
+++ b/src/core/iomgr/resolve_address_windows.c
@@ -40,9 +40,9 @@
 #include <sys/types.h>
 #include <string.h>
 
-#include "src/core/iomgr/block_annotate.h"
 #include "src/core/iomgr/iomgr_internal.h"
 #include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/support/block_annotate.h"
 #include "src/core/support/string.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
@@ -89,9 +89,9 @@ grpc_resolved_addresses *grpc_blocking_resolve_address(
   hints.ai_socktype = SOCK_STREAM; /* stream socket */
   hints.ai_flags = AI_PASSIVE;     /* for wildcard IP address */
 
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   s = getaddrinfo(host, port, &hints, &result);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   if (s != 0) {
     gpr_log(GPR_ERROR, "getaddrinfo: %s", gai_strerror(s));
     goto done;
diff --git a/src/core/iomgr/block_annotate.h b/src/core/support/block_annotate.h
similarity index 86%
rename from src/core/iomgr/block_annotate.h
rename to src/core/support/block_annotate.h
index c962da0a891..bf2c17f8595 100644
--- a/src/core/iomgr/block_annotate.h
+++ b/src/core/support/block_annotate.h
@@ -31,14 +31,14 @@
  *
  */
 
-#ifndef GRPC_INTERNAL_CORE_IOMGR_BLOCK_ANNOTATE_H
-#define GRPC_INTERNAL_CORE_IOMGR_BLOCK_ANNOTATE_H
+#ifndef GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H
+#define GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H
 
 /* These annotations identify the beginning and end of regions where
    the code may block for reasons other than synchronization functions.
    These include poll, epoll, and getaddrinfo. */
 
-#define GRPC_IOMGR_START_BLOCKING_REGION do {} while (0)
-#define GRPC_IOMGR_END_BLOCKING_REGION do {} while (0)
+#define GRPC_SCHEDULING_START_BLOCKING_REGION do {} while (0)
+#define GRPC_SCHEDULING_END_BLOCKING_REGION do {} while (0)
 
-#endif /* GRPC_INTERNAL_CORE_IOMGR_BLOCK_ANNOTATE_H */
+#endif /* GRPC_INTERNAL_CORE_SUPPORT_BLOCK_ANNOTATE_H */
diff --git a/src/core/support/file.c b/src/core/support/file.c
index 25a566905e5..8c673dbcc66 100644
--- a/src/core/support/file.c
+++ b/src/core/support/file.c
@@ -40,7 +40,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
-#include "src/core/iomgr/block_annotate.h"
+#include "src/core/support/block_annotate.h"
 #include "src/core/support/string.h"
 
 gpr_slice gpr_load_file(const char *filename, int add_null_terminator,
@@ -52,7 +52,7 @@ gpr_slice gpr_load_file(const char *filename, int add_null_terminator,
   FILE *file;
   size_t bytes_read = 0;
 
-  GRPC_IOMGR_START_BLOCKING_REGION;
+  GRPC_SCHEDULING_START_BLOCKING_REGION;
   file = fopen(filename, "rb");
   if (file == NULL) {
     gpr_asprintf(&error_msg, "Could not open file %s (error = %s).", filename,
@@ -86,6 +86,6 @@ end:
     if (success != NULL) *success = 0;
   }
   if (file != NULL) fclose(file);
-  GRPC_IOMGR_END_BLOCKING_REGION;
+  GRPC_SCHEDULING_END_BLOCKING_REGION;
   return result;
 }
diff --git a/src/core/support/time_posix.c b/src/core/support/time_posix.c
index 889b63a88af..eedfd0a0607 100644
--- a/src/core/support/time_posix.c
+++ b/src/core/support/time_posix.c
@@ -41,7 +41,7 @@
 #include <unistd.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
-#include "src/core/iomgr/block_annotate.h"
+#include "src/core/support/block_annotate.h"
 
 static struct timespec timespec_from_gpr(gpr_timespec gts) {
   struct timespec rv;
@@ -139,9 +139,9 @@ void gpr_sleep_until(gpr_timespec until) {
 
     delta = gpr_time_sub(until, now);
     delta_ts = timespec_from_gpr(delta);
-    GRPC_IOMGR_START_BLOCKING_REGION;
+    GRPC_SCHEDULING_START_BLOCKING_REGION;
     ns_result = nanosleep(&delta_ts, NULL);
-    GRPC_IOMGR_END_BLOCKING_REGION;
+    GRPC_SCHEDULING_END_BLOCKING_REGION;
     if (ns_result == 0) {
       break;
     }
diff --git a/src/core/support/time_win32.c b/src/core/support/time_win32.c
index 710c7969bad..bc0586d0691 100644
--- a/src/core/support/time_win32.c
+++ b/src/core/support/time_win32.c
@@ -41,7 +41,7 @@
 #include <src/core/support/time_precise.h>
 #include <sys/timeb.h>
 
-#include "src/core/iomgr/block_annotate.h"
+#include "src/core/support/block_annotate.h"
 
 static LARGE_INTEGER g_start_time;
 static double g_time_scale;
@@ -94,9 +94,9 @@ void gpr_sleep_until(gpr_timespec until) {
     delta = gpr_time_sub(until, now);
     sleep_millis =
         (DWORD)delta.tv_sec * GPR_MS_PER_SEC + delta.tv_nsec / GPR_NS_PER_MS;
-    GRPC_IOMGR_START_BLOCKING_REGION;
+    GRPC_SCHEDULING_START_BLOCKING_REGION;
     Sleep(sleep_millis);
-    GRPC_IOMGR_END_BLOCKING_REGION;
+    GRPC_SCHEDULING_END_BLOCKING_REGION;
   }
 }
 
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index f38bee2bc0c..88b125356da 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -815,7 +815,6 @@ src/core/httpcli/parser.h \
 src/core/iomgr/alarm.h \
 src/core/iomgr/alarm_heap.h \
 src/core/iomgr/alarm_internal.h \
-src/core/iomgr/block_annotate.h \
 src/core/iomgr/endpoint.h \
 src/core/iomgr/endpoint_pair.h \
 src/core/iomgr/fd_posix.h \
@@ -1059,6 +1058,7 @@ include/grpc/support/tls_gcc.h \
 include/grpc/support/tls_msvc.h \
 include/grpc/support/tls_pthread.h \
 include/grpc/support/useful.h \
+src/core/support/block_annotate.h \
 src/core/support/env.h \
 src/core/support/file.h \
 src/core/support/murmur_hash.h \
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index 28361adee94..97c7949ef24 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -12161,6 +12161,7 @@
       "include/grpc/support/tls_msvc.h", 
       "include/grpc/support/tls_pthread.h", 
       "include/grpc/support/useful.h", 
+      "src/core/support/block_annotate.h", 
       "src/core/support/env.h", 
       "src/core/support/file.h", 
       "src/core/support/murmur_hash.h", 
@@ -12201,6 +12202,7 @@
       "include/grpc/support/tls_pthread.h", 
       "include/grpc/support/useful.h", 
       "src/core/support/alloc.c", 
+      "src/core/support/block_annotate.h", 
       "src/core/support/cmdline.c", 
       "src/core/support/cpu_iphone.c", 
       "src/core/support/cpu_linux.c", 
@@ -12311,7 +12313,6 @@
       "src/core/iomgr/alarm.h", 
       "src/core/iomgr/alarm_heap.h", 
       "src/core/iomgr/alarm_internal.h", 
-      "src/core/iomgr/block_annotate.h", 
       "src/core/iomgr/endpoint.h", 
       "src/core/iomgr/endpoint_pair.h", 
       "src/core/iomgr/fd_posix.h", 
@@ -12483,7 +12484,6 @@
       "src/core/iomgr/alarm_heap.c", 
       "src/core/iomgr/alarm_heap.h", 
       "src/core/iomgr/alarm_internal.h", 
-      "src/core/iomgr/block_annotate.h", 
       "src/core/iomgr/endpoint.c", 
       "src/core/iomgr/endpoint.h", 
       "src/core/iomgr/endpoint_pair.h", 
@@ -12802,7 +12802,6 @@
       "src/core/iomgr/alarm.h", 
       "src/core/iomgr/alarm_heap.h", 
       "src/core/iomgr/alarm_internal.h", 
-      "src/core/iomgr/block_annotate.h", 
       "src/core/iomgr/endpoint.h", 
       "src/core/iomgr/endpoint_pair.h", 
       "src/core/iomgr/fd_posix.h", 
@@ -12959,7 +12958,6 @@
       "src/core/iomgr/alarm_heap.c", 
       "src/core/iomgr/alarm_heap.h", 
       "src/core/iomgr/alarm_internal.h", 
-      "src/core/iomgr/block_annotate.h", 
       "src/core/iomgr/endpoint.c", 
       "src/core/iomgr/endpoint.h", 
       "src/core/iomgr/endpoint_pair.h", 
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj b/vsprojects/vcxproj/gpr/gpr.vcxproj
index a130f5961e7..1ffa0a858e9 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj
@@ -151,6 +151,7 @@
     <ClInclude Include="..\..\..\include\grpc\support\useful.h" />
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="..\..\..\src\core\support\block_annotate.h" />
     <ClInclude Include="..\..\..\src\core\support\env.h" />
     <ClInclude Include="..\..\..\src\core\support\file.h" />
     <ClInclude Include="..\..\..\src\core\support\murmur_hash.h" />
diff --git a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
index 98b9121392f..be5bb5162d3 100644
--- a/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
+++ b/vsprojects/vcxproj/gpr/gpr.vcxproj.filters
@@ -197,6 +197,9 @@
     </ClInclude>
   </ItemGroup>
   <ItemGroup>
+    <ClInclude Include="..\..\..\src\core\support\block_annotate.h">
+      <Filter>src\core\support</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\..\src\core\support\env.h">
       <Filter>src\core\support</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj b/vsprojects/vcxproj/grpc/grpc.vcxproj
index 007ad41999d..a09e813a5a0 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj
@@ -277,7 +277,6 @@
     <ClInclude Include="..\..\..\src\core\iomgr\alarm.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_heap.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_internal.h" />
-    <ClInclude Include="..\..\..\src\core\iomgr\block_annotate.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint_pair.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\fd_posix.h" />
diff --git a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
index a52db5178f0..1538c335528 100644
--- a/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc/grpc.vcxproj.filters
@@ -602,9 +602,6 @@
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_internal.h">
       <Filter>src\core\iomgr</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\..\src\core\iomgr\block_annotate.h">
-      <Filter>src\core\iomgr</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint.h">
       <Filter>src\core\iomgr</Filter>
     </ClInclude>
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
index 738a9ab6275..1ef4aadf524 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj
@@ -256,7 +256,6 @@
     <ClInclude Include="..\..\..\src\core\iomgr\alarm.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_heap.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_internal.h" />
-    <ClInclude Include="..\..\..\src\core\iomgr\block_annotate.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint_pair.h" />
     <ClInclude Include="..\..\..\src\core\iomgr\fd_posix.h" />
diff --git a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
index 040b34344f6..da199b05f18 100644
--- a/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
+++ b/vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters
@@ -500,9 +500,6 @@
     <ClInclude Include="..\..\..\src\core\iomgr\alarm_internal.h">
       <Filter>src\core\iomgr</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\..\src\core\iomgr\block_annotate.h">
-      <Filter>src\core\iomgr</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\..\src\core\iomgr\endpoint.h">
       <Filter>src\core\iomgr</Filter>
     </ClInclude>