diff -uprN ./mysql-5.7.17/sql/mysqld.cc ./mysql-5.7.17.new/sql/mysqld.cc
--- ./mysql-5.7.17/sql/mysqld.cc	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/sql/mysqld.cc	2017-09-01 11:02:17.000000000 +0800
@@ -483,6 +483,9 @@ bool host_cache_size_specified= false;
 bool table_definition_cache_specified= false;
 ulong locked_account_connection_count= 0;
 
+/* TDSQL: reduce CPU occupancy */
+ulong idle_sleep_us; /*!< time to sleep(us) when idle */
+
 /**
   Limit of the total number of prepared statements in the server.
   Is necessary to protect the server against out-of-memory attacks.
diff -uprN ./mysql-5.7.17/sql/mysqld.h ./mysql-5.7.17.new/sql/mysqld.h
--- ./mysql-5.7.17/sql/mysqld.h	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/sql/mysqld.h	2017-09-01 11:01:20.000000000 +0800
@@ -974,4 +974,7 @@ static inline THD *_current_thd(void)
 
 #define ER(X)         ER_THD(current_thd,X)
 
+/* TDSQL: reduce CPU occupancy */
+extern ulong idle_sleep_us; /*!< time to sleep(us) when idle */
+
 #endif /* MYSQLD_INCLUDED */
diff -uprN ./mysql-5.7.17/sql/sys_vars.cc ./mysql-5.7.17.new/sql/sys_vars.cc
--- ./mysql-5.7.17/sql/sys_vars.cc	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/sql/sys_vars.cc	2017-09-01 11:05:01.000000000 +0800
@@ -2402,6 +2402,14 @@ static Sys_var_uint Sys_pseudo_thread_id
        BLOCK_SIZE(1), NO_MUTEX_GUARD, IN_BINLOG,
        ON_CHECK(check_has_super));
 
+/* TDSQL: reduce CPU occupancy */
+static Sys_var_ulong Sys_global_sleep_us(
+       "idle_sleep_us", "used in buf/buf0flu.cc",
+       GLOBAL_VAR(idle_sleep_us), CMD_LINE(OPT_ARG),
+       VALID_RANGE(0, 1000000), DEFAULT(10000), BLOCK_SIZE(1),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG,
+       ON_CHECK(0), ON_UPDATE(0));
+
 static bool fix_max_join_size(sys_var *self, THD *thd, enum_var_type type)
 {
   SV *sv= type == OPT_GLOBAL ? &global_system_variables : &thd->variables;
diff -uprN ./mysql-5.7.17/storage/innobase/buf/buf0buf.cc ./mysql-5.7.17.new/storage/innobase/buf/buf0buf.cc
--- ./mysql-5.7.17/storage/innobase/buf/buf0buf.cc	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/storage/innobase/buf/buf0buf.cc	2017-09-01 11:27:04.000000000 +0800
@@ -321,6 +321,9 @@ static const ulint	BUF_READ_AHEAD_PORTIO
 /** The buffer pools of the database */
 buf_pool_t*	buf_pool_ptr;
 
+/* TDSQL: reduce CPU occupancy */
+MY_BITMAP  buf_pend_reads;
+
 /** true when resizing buffer pool is in the critical path. */
 volatile bool	buf_pool_resizing;
 
@@ -1949,6 +1952,10 @@ buf_pool_init(
 	buf_pool_ptr = (buf_pool_t*) ut_zalloc_nokey(
 		n_instances * sizeof *buf_pool_ptr);
 
+	/* TDSQL: reduce CPU occupancy */
+	bitmap_init(&buf_pend_reads, 0, n_instances, 0);
+	bitmap_clear_all(&buf_pend_reads);
+
 	buf_chunk_map_reg = UT_NEW_NOKEY(buf_pool_chunk_map_t());
 
 	for (i = 0; i < n_instances; i++) {
@@ -1990,6 +1997,9 @@ buf_pool_free(
 
 	ut_free(buf_pool_ptr);
 	buf_pool_ptr = NULL;
+
+	/* TDSQL: reduce CPU occupancy */
+	bitmap_free(&buf_pend_reads);
 }
 
 /** Reallocate a control block.
@@ -5116,6 +5126,9 @@ buf_page_init_for_read(
 	void*		data;
 	buf_pool_t*	buf_pool = buf_pool_get(page_id);
 
+	/* TDSQL: reduce CPU occupancy */               
+	ulint buffer_pool_index = buf_pool_index(buf_pool);
+
 	ut_ad(buf_pool);
 
 	*err = DB_SUCCESS;
@@ -5316,6 +5329,8 @@ buf_page_init_for_read(
 		mutex_exit(&buf_pool->zip_mutex);
 	}
 
+	/* TDSQL: reduce CPU occupancy */
+	bitmap_set_bit(&buf_pend_reads, buffer_pool_index);
 	buf_pool->n_pend_reads++;
 func_exit:
 	buf_pool_mutex_exit(buf_pool);
@@ -5624,6 +5639,12 @@ buf_mark_space_corrupt(
 	ut_ad(buf_pool->n_pend_reads > 0);
 	buf_pool->n_pend_reads--;
 
+/* TDSQL: reduce CPU occupancy */
+	if (buf_pool->n_pend_reads == 0) {
+		ulint buffer_pool_index = buf_pool_index(buf_pool);
+		bitmap_clear_bit(&buf_pend_reads, buffer_pool_index);
+	}
+
 	buf_pool_mutex_exit(buf_pool);
 
 	return(ret);
@@ -5854,6 +5875,13 @@ corrupt:
 
 		ut_ad(buf_pool->n_pend_reads > 0);
 		buf_pool->n_pend_reads--;
+
+		/* TDSQL: reduce CPU occupancy */
+		if (buf_pool->n_pend_reads == 0) {
+			ulint buffer_pool_index = buf_pool_index(buf_pool);
+			bitmap_clear_bit(&buf_pend_reads, buffer_pool_index);
+		}
+
 		buf_pool->stat.n_pages_read++;
 
 		if (uncompressed) {
@@ -6498,19 +6526,17 @@ buf_get_latched_pages_number(void)
 #endif /* UNIV_DEBUG */
 
 /*********************************************************************//**
-Returns the number of pending buf pool read ios.
-@return number of pending read I/O operations */
+Returns whether there exists buf pool whose pending read ios is not 0.
+@return whether any of buf_pend_reads.bitmap is not 0 */
 ulint
 buf_get_n_pending_read_ios(void)
 /*============================*/
 {
-	ulint	pend_ios = 0;
-
-	for (ulint i = 0; i < srv_buf_pool_instances; i++) {
-		pend_ios += buf_pool_from_array(i)->n_pend_reads;
+	for (ulint i = 0; i < bitmap_buffer_size(buf_pend_reads.n_bits) / sizeof(my_bitmap_map); i++) {
+		if (buf_pend_reads.bitmap[i])
+		return 1;
 	}
-
-	return(pend_ios);
+	return 0;
 }
 
 /*********************************************************************//**
diff -uprN ./mysql-5.7.17/storage/innobase/buf/buf0flu.cc ./mysql-5.7.17.new/storage/innobase/buf/buf0flu.cc
--- ./mysql-5.7.17/storage/innobase/buf/buf0flu.cc	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/storage/innobase/buf/buf0flu.cc	2017-09-01 11:28:09.000000000 +0800
@@ -3357,6 +3357,9 @@ DECLARE_THREAD(buf_flush_page_cleaner_co
 		} else {
 			/* no activity, but woken up by event */
 			n_flushed = 0;
+			/* TDSQL: reduce CPU occupancy */
+			if (idle_sleep_us != 0)
+				os_event_wait_time_low(buf_flush_event, idle_sleep_us, sig_count);
 		}
 
 		ut_d(buf_flush_page_cleaner_disabled_loop());
diff -uprN ./mysql-5.7.17/storage/innobase/buf/buf0rea.cc ./mysql-5.7.17.new/storage/innobase/buf/buf0rea.cc
--- ./mysql-5.7.17/storage/innobase/buf/buf0rea.cc	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/storage/innobase/buf/buf0rea.cc	2017-09-01 11:41:09.000000000 +0800
@@ -86,6 +86,12 @@ buf_read_page_handle_error(
 	ut_ad(buf_pool->n_pend_reads > 0);
 	buf_pool->n_pend_reads--;
 
+	/* TDSQL: reduce CPU occupancy */
+	if (buf_pool->n_pend_reads == 0) {
+		ulint buffer_pool_index = buf_pool_index(buf_pool);
+		bitmap_clear_bit(&buf_pend_reads, buffer_pool_index);
+	}
+
 	buf_pool_mutex_exit(buf_pool);
 }
 
diff -uprN ./mysql-5.7.17/storage/innobase/include/buf0buf.h ./mysql-5.7.17.new/storage/innobase/include/buf0buf.h
--- ./mysql-5.7.17/storage/innobase/include/buf0buf.h	2016-11-28 21:32:52.000000000 +0800
+++ ./mysql-5.7.17.new/storage/innobase/include/buf0buf.h	2017-09-01 11:08:25.000000000 +0800
@@ -41,6 +41,8 @@ Created 11/5/1995 Heikki Tuuri
 #include "srv0srv.h"
 #include <ostream>
 
+#include "my_bitmap.h"
+
 // Forward declaration
 struct fil_addr_t;