Bug #57707 InnoDB buf_page_t size has doubled on 32-bit systems

buf_page_t: Remove the buf_pool pointer. Add buf_pool_index:6 next to
buf_fix_count:19 (it was buf_fix_count:25). This will limit the number
of concurrent transactions to somewhere around 524,288.

buf_pool_index(buf_pool): A new function to determine the index of a
buffer pool in buf_pool_ptr[].

buf_pool_ptr: Make this a dynamically allocated array instead of an
array of pointers. Allocate the array in buf_pool_init() and free in
buf_pool_free().

buf_pool_free_instance(): No longer free the buf_pool object, as it is
allocated from a big array.

buf_pool_from_bpage(), buf_pool_from_block(): Move the definitions to
the beginning of the files, because some compilers have (had) problems
with forward definitions of inline functions. Calculate the buffer
pool from buf_pool_index.

buf_pool_from_array(): Add debug assertions for input validation.

1 files changed, 19 insertions, 6 deletions

diff --git a/storage/innobase/include/buf0buf.h b/storage/innobase/include/buf0buf.h
index b0fff919918..a42eba57fd2 100644
--- a/storage/innobase/include/buf0buf.h
+++ b/storage/innobase/include/buf0buf.h
@@ -69,7 +69,7 @@ Created 11/5/1995 Heikki Tuuri
 #define BUF_POOL_WATCH_SIZE 1		/*!< Maximum number of concurrent
 					buffer pool watches */
 
-extern	buf_pool_t*	buf_pool_ptr[MAX_BUFFER_POOLS]; /*!< The buffer pools
+extern	buf_pool_t*	buf_pool_ptr;	/*!< The buffer pools
 					of the database */
 #ifdef UNIV_DEBUG
 extern ibool		buf_debug_prints;/*!< If this is set TRUE, the program
@@ -1034,6 +1034,15 @@ buf_page_address_fold(
 	ulint	space,	/*!< in: space id */
 	ulint	offset)	/*!< in: offset of the page within space */
 	__attribute__((const));
+/********************************************************************//**
+Calculates the index of a buffer pool to the buf_pool[] array.
+@return	the position of the buffer pool in buf_pool[] */
+UNIV_INLINE
+ulint
+buf_pool_index(
+/*===========*/
+	const buf_pool_t*	buf_pool)	/*!< in: buffer pool */
+	__attribute__((nonnull, const));
 /******************************************************************//**
 Returns the buffer pool instance given a page instance
 @return buf_pool */
@@ -1065,8 +1074,9 @@ Returns the buffer pool instance given its array index
 UNIV_INLINE
 buf_pool_t*
 buf_pool_from_array(
-/*====================*/
-	ulint	index);	/*!< in: array index to get buffer pool instance from */
+/*================*/
+	ulint	index);		/*!< in: array index to get
+				buffer pool instance from */
 /******************************************************************//**
 Returns the control block of a file page, NULL if not found.
 @return	block, NULL if not found */
@@ -1204,8 +1214,13 @@ struct buf_page_struct{
 	unsigned	io_fix:2;	/*!< type of pending I/O operation;
 					also protected by buf_pool->mutex
 					@see enum buf_io_fix */
-	unsigned	buf_fix_count:25;/*!< count of how manyfold this block
+	unsigned	buf_fix_count:19;/*!< count of how manyfold this block
 					is currently bufferfixed */
+	unsigned	buf_pool_index:6;/*!< index number of the buffer pool
+					that this block belongs to */
+# if MAX_BUFFER_POOLS > 64
+#  error "MAX_BUFFER_POOLS > 64; redefine buf_pool_index:6"
+# endif
 	/* @} */
 #endif /* !UNIV_HOTBACKUP */
 	page_zip_des_t	zip;		/*!< compressed page; zip.data
@@ -1324,8 +1339,6 @@ struct buf_page_struct{
 					frees a page in buffer pool */
 # endif /* UNIV_DEBUG_FILE_ACCESSES */
 #endif /* !UNIV_HOTBACKUP */
-	buf_pool_t*	buf_pool;	/*!< buffer pool instance this
-					page belongs to */
 };
 
 /** The buffer control block structure */