squash! 7c5068ff

Revert the change to buf_pool_t::page_cleaner_wakeup() and
unconditionally wake up the page cleaner if we are running
out of buffer pool.

storage/innobase/buf/buf0flu.cc

@@ -112,17 +112,11 @@ static void buf_flush_validate_skip()
 }
 #endif /* UNIV_DEBUG */
 
-void buf_pool_t::page_cleaner_wakeup(wakeup_reason reason)
+void buf_pool_t::page_cleaner_wakeup(bool for_LRU)
 {
   if (!page_cleaner_idle())
   {
-    /* Many ISA provide N and Z flags, which we desire to use for
-    efficient checking of the wakeup reason. */
-    static_assert(WAKE_NOW_LRU < 0, "efficiency");
-    static_assert(WAKE_IDLE == 0, "efficiency");
-    static_assert(WAKE_IDLE_LRU > 0, "efficiency");
-
-    if (reason < WAKE_IDLE)
+    if (for_LRU)
       /* Ensure that the page cleaner is not in a timed wait. */
       pthread_cond_signal(&do_flush_list);
     return;
@@ -156,7 +150,7 @@ void buf_pool_t::page_cleaner_wakeup(wakeup_reason reason)
   - by allowing last_activity_count to updated when page-cleaner is made
     active and has work to do. This ensures that the last_activity signal
     is consumed by the page-cleaner before the next one is generated. */
-  if (reason != WAKE_IDLE ||
+  if (for_LRU ||
       (pct_lwm != 0.0 && (pct_lwm <= dirty_pct ||
                           last_activity_count == srv_get_activity_count())) ||
       srv_max_buf_pool_modified_pct <= dirty_pct)

storage/innobase/buf/buf0lru.cc

@@ -426,9 +426,7 @@ buf_block_t *buf_LRU_get_free_block(bool have_mutex)
 
 		if (UNIV_UNLIKELY(available < scan_depth)) {
 			mysql_mutex_lock(&buf_pool.flush_list_mutex);
-			buf_pool.page_cleaner_wakeup(available < scan_depth / 2
-						     ? buf_pool.WAKE_NOW_LRU
-						     : buf_pool.WAKE_IDLE_LRU);
+			buf_pool.page_cleaner_wakeup(true);
 			mysql_mutex_unlock(&buf_pool.flush_list_mutex);
 		}
 
@@ -461,7 +459,7 @@ buf_block_t *buf_LRU_get_free_block(bool have_mutex)
 		mysql_mutex_lock(&buf_pool.flush_list_mutex);
 		const auto n_flush = buf_pool.n_flush();
 		if (!buf_pool.try_LRU_scan) {
-			buf_pool.page_cleaner_wakeup(buf_pool.WAKE_NOW_LRU);
+			buf_pool.page_cleaner_wakeup(true);
 		}
 		mysql_mutex_unlock(&buf_pool.flush_list_mutex);
 		mysql_mutex_lock(&buf_pool.mutex);

storage/innobase/include/buf0buf.h

@@ -1777,17 +1777,9 @@ class buf_pool_t
     return page_cleaner_status > PAGE_CLEANER_IDLE;
   }
 
-  enum wakeup_reason {
-    /** Immediately wake up for LRU eviction */
-    WAKE_NOW_LRU= -1,
-    /** Wake up normally from indefinite sleep (@see page_cleaner_idle()) */
-    WAKE_IDLE= 0,
-    /** Wake up due to LRU eviction from indefinite sleep */
-    WAKE_IDLE_LRU
-  };
   /** Wake up the page cleaner if needed.
-  @param reason  how the page cleaner should be woken up */
-  void page_cleaner_wakeup(wakeup_reason reason= WAKE_IDLE);
+  @param for_LRU  whether to wake up for LRU eviction */
+  void page_cleaner_wakeup(bool for_LRU= false);
 
   /** Register whether an explicit wakeup of the page cleaner is needed */
   void page_cleaner_set_idle(bool deep_sleep)