MDEV-23719: Remove buf_block_t::lock_hash_val

The InnoDB buffer block page descriptor is caching a value
buf_block_t::lock_hash_val that should be quick to compute
in the first place, as suggested by
commit 14be8143.

lock_rec_fold(): Define as page_id_t::fold() instead of
ut_fold_ulint_pair().

storage/innobase/buf/buf0buf.cc

@@ -1763,10 +1763,6 @@ inline bool buf_pool_t::realloc(buf_block_t *block)
 		new_block->left_side	= TRUE;
 #endif /* BTR_CUR_HASH_ADAPT */
 
-		new_block->lock_hash_val = block->lock_hash_val;
-		ut_ad(new_block->lock_hash_val == lock_rec_hash(
-			      id.space(), id.page_no()));
-
 		hash_lock->write_unlock();
 
 		/* free block */
@@ -3368,9 +3364,6 @@ buf_page_get_low(
 		/* Set after buf_relocate(). */
 		block->page.set_buf_fix_count(1);
 
-		block->lock_hash_val = lock_rec_hash(page_id.space(),
-						     page_id.page_no());
-
 		if (!block->page.oldest_modification()) {
 			ut_d(UT_LIST_REMOVE(buf_pool.zip_clean, &block->page));
 		} else {
@@ -3800,7 +3793,6 @@ void buf_block_t::initialise(const page_id_t page_id, ulint zip_size,
 {
   ut_ad(page.state() != BUF_BLOCK_FILE_PAGE);
   buf_block_init_low(this);
-  lock_hash_val= lock_rec_hash(page_id.space(), page_id.page_no());
   page.init(page_id, fix);
   page_zip_set_size(&page.zip, zip_size);
 }
@@ -3884,8 +3876,6 @@ buf_page_create(fil_space_t *space, uint32_t offset,
 #endif
 
       free_block->page.set_state(BUF_BLOCK_FILE_PAGE);
-      free_block->lock_hash_val= lock_rec_hash(
-        page_id.space(), page_id.page_no());
       buf_unzip_LRU_add_block(free_block, FALSE);
       hash_lock->write_unlock();
       buf_page_free_descriptor(&block->page);

storage/innobase/gis/gis0sea.cc

@@ -1528,7 +1528,6 @@ rtr_copy_buf(
 	ut_d(matches->block.in_withdraw_list = block->in_withdraw_list);
 
 	/* Skip buf_block_t::lock */
-	matches->block.lock_hash_val = block->lock_hash_val;
 	matches->block.modify_clock = block->modify_clock;
 #ifdef BTR_CUR_HASH_ADAPT
 	matches->block.n_hash_helps = block->n_hash_helps;

storage/innobase/include/buf0buf.h

@@ -596,16 +596,6 @@ inline uint buf_page_full_crc32_size(const byte* buf, bool* comp, bool* cr)
 }
 
 #ifndef UNIV_INNOCHECKSUM
-/**********************************************************************//**
-Gets the hash value of a block. This can be used in searches in the
-lock hash table.
-@return lock hash value */
-UNIV_INLINE
-unsigned
-buf_block_get_lock_hash_val(
-/*========================*/
-	const buf_block_t*	block)	/*!< in: block */
-	MY_ATTRIBUTE((warn_unused_result));
 #ifdef UNIV_DEBUG
 /** Find a block in the buffer pool that points to a given compressed page.
 @param[in]	data		pointer to compressed page
@@ -1070,13 +1060,6 @@ struct buf_block_t{
 					a block is in the unzip_LRU list
 					if page.state() == BUF_BLOCK_FILE_PAGE
 					and page.zip.data != NULL */
-	uint32_t	lock_hash_val;	/*!< hashed value of the page address
-					in the record lock hash table;
-					protected by buf_block_t::lock
-					(or buf_pool.mutex
-				        in buf_page_get_gen(),
-					buf_page_init_for_read()
-					and buf_page_create()) */
 	/* @} */
 	/** @name Optimistic search field */
 	/* @{ */

storage/innobase/include/buf0buf.ic

@@ -154,24 +154,6 @@ ok:
 }
 #endif /* UNIV_DEBUG */
 
-/**********************************************************************//**
-Gets the hash value of the page the pointer is pointing to. This can be used
-in searches in the lock hash table.
-@return lock hash value */
-UNIV_INLINE
-unsigned
-buf_block_get_lock_hash_val(
-/*========================*/
-	const buf_block_t*	block)	/*!< in: block */
-{
-	ut_ad(block);
-	ut_ad(block->page.in_file());
-	ut_ad(rw_lock_own(&(((buf_block_t*) block)->lock), RW_LOCK_X)
-	      || rw_lock_own(&(((buf_block_t*) block)->lock), RW_LOCK_S));
-
-	return(block->lock_hash_val);
-}
-
 /********************************************************************//**
 Allocates a buf_page_t descriptor. This function must succeed. In case
 of failure we assert in this function.

storage/innobase/include/lock0lock.ic

@@ -39,7 +39,7 @@ lock_rec_fold(
 	ulint	space,	/*!< in: space */
 	ulint	page_no)/*!< in: page number */
 {
-	return(ut_fold_ulint_pair(space, page_no));
+	return page_id_t(space, page_no).fold();
 }
 
 /*********************************************************************//**

storage/innobase/include/lock0priv.ic

@@ -164,12 +164,14 @@ lock_rec_get_first_on_page(
 {
 	ut_ad(lock_mutex_own());
 
-	ulint	space	= block->page.id().space();
-	ulint	page_no	= block->page.id().page_no();
-	ulint	hash = buf_block_get_lock_hash_val(block);
+	const page_id_t page_id(block->page.id());
+
+	ulint	space	= page_id.space();
+	ulint	page_no	= page_id.page_no();
 
 	for (lock_t* lock = static_cast<lock_t*>(
-			HASH_GET_FIRST(lock_hash, hash));
+			HASH_GET_FIRST(lock_hash,
+				       lock_rec_hash(space, page_no)));
 	     lock != NULL;
 	     lock = static_cast<lock_t*>(HASH_GET_NEXT(hash, lock))) {
 

storage/innobase/lock/lock0lock.cc

@@ -515,18 +515,6 @@ void lock_sys_t::resize(ulint n_cells)
 	HASH_MIGRATE(&old_hash, &prdt_page_hash, lock_t, hash,
 		     lock_rec_lock_fold);
 	old_hash.free();
-
-	/* need to update block->lock_hash_val */
-	mutex_enter(&buf_pool.mutex);
-	for (buf_page_t* bpage = UT_LIST_GET_FIRST(buf_pool.LRU);
-	     bpage; bpage = UT_LIST_GET_NEXT(LRU, bpage)) {
-		if (bpage->state() == BUF_BLOCK_FILE_PAGE) {
-			const page_id_t id(bpage->id());
-			reinterpret_cast<buf_block_t*>(bpage)->lock_hash_val
-				= lock_rec_hash(id.space(), id.page_no());
-		}
-	}
-	mutex_exit(&buf_pool.mutex);
 	mutex_exit(&mutex);
 }