branches/zip: Allow the buddy allocator to work for 16-kilobyte pages,

twice the maximum block size of the buddy system.

buf_page_t: Note that state may change from BUF_BLOCK_READY_FOR_USE
to BUF_BLOCK_MEMORY without buf_page_get_mutex() protection
[only buf_pool->mutex].

buf_buddy_get_slot(): Extend the output to BUF_BUDDY_SIZES.

buf_buddy_alloc(), buf_buddy_free(): Allow sizes up to UNIV_PAGE_SIZE.

buf_buddy_alloc_low(), buf_buddy_free_low(), buf_buddy_alloc_clean():
Allow i==BUF_BUDDY_SIZES.

buf/buf0buddy.c

@@ -165,7 +165,8 @@ buf_buddy_alloc_clean(
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
 
-	if (BUF_BUDDY_LOW << i >= PAGE_ZIP_MIN_SIZE) {
+	if (BUF_BUDDY_LOW << i >= PAGE_ZIP_MIN_SIZE
+	    && i < BUF_BUDDY_SIZES) {
 		/* Try to find a clean compressed-only page
 		of the same size. */
 
@@ -225,11 +226,21 @@ buf_buddy_alloc_clean(
 
 		mutex_exit(block_mutex);
 
-		ret = buf_buddy_alloc_zip(i);
+		if (i < BUF_BUDDY_SIZES) {
 
-		if (ret) {
+			ret = buf_buddy_alloc_zip(i);
 
-			return(ret);
+			if (ret) {
+
+				return(ret);
+			}
+		} else {
+			buf_block_t*	block = buf_LRU_get_free_only();
+
+			if (block) {
+				buf_buddy_block_register(block);
+				return(block->frame);
+			}
 		}
 	}
 
@@ -244,7 +255,8 @@ buf_buddy_alloc_low(
 /*================*/
 			/* out: allocated block, or NULL
 			if buf_pool->zip_free[] was empty */
-	ulint	i,	/* in: index of buf_pool->zip_free[] */
+	ulint	i,	/* in: index of buf_pool->zip_free[],
+			or BUF_BUDDY_SIZES */
 	ibool	lru)	/* in: TRUE=allocate from the LRU list if needed */
 {
 	buf_block_t*	block;
@@ -253,12 +265,14 @@ buf_buddy_alloc_low(
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
 
-	/* Try to allocate from the buddy system. */
-	block = buf_buddy_alloc_zip(i);
+	if (i < BUF_BUDDY_SIZES) {
+		/* Try to allocate from the buddy system. */
+		block = buf_buddy_alloc_zip(i);
 
-	if (block) {
+		if (block) {
 
-		return(block);
+			return(block);
+		}
 	}
 
 	/* Try allocating from the buf_pool->free list. */
@@ -441,6 +455,11 @@ buf_buddy_free_low(
 	ut_a(mutex_own(&buf_pool->mutex));
 #endif /* UNIV_SYNC_DEBUG */
 recombine:
+	if (i == BUF_BUDDY_SIZES) {
+		buf_buddy_block_free(buf);
+		return;
+	}
+
 	ut_ad(i < BUF_BUDDY_SIZES);
 	ut_ad(buf == ut_align_down(buf, BUF_BUDDY_LOW << i));
 	ut_ad(!buf_pool_contains_zip(buf));
@@ -468,16 +487,10 @@ buddy_free:
 			UT_LIST_REMOVE(list, buf_pool->zip_free[i], bpage);
 buddy_free2:
 			ut_ad(!buf_pool_contains_zip(buddy));
-			buf = ut_align_down(buf, BUF_BUDDY_LOW << (i + 1));
-
-			if (++i < BUF_BUDDY_SIZES) {
-
-				goto recombine;
-			}
+			i++;
+			buf = ut_align_down(buf, BUF_BUDDY_LOW << i);
 
-			/* The whole block is free. */
-			buf_buddy_block_free(buf);
-			return;
+			goto recombine;
 		}
 
 		ut_a(bpage != buf);

include/buf0buddy.h

@@ -39,7 +39,8 @@ UNIV_INLINE
 ulint
 buf_buddy_get_slot(
 /*===============*/
-			/* out: index of buf_pool->zip_free[] */
+			/* out: index of buf_pool->zip_free[],
+			or BUF_BUDDY_SIZES */
 	ulint	size);	/* in: block size */
 
 /**************************************************************************
@@ -49,7 +50,7 @@ void*
 buf_buddy_alloc(
 /*============*/
 			/* out: pointer to the start of the block */
-	ulint	size,	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+	ulint	size,	/* in: block size, up to UNIV_PAGE_SIZE */
 	ibool	lru)	/* in: TRUE=allocate from the LRU list if needed */
 	__attribute__((malloc));
 
@@ -61,7 +62,7 @@ buf_buddy_free(
 /*===========*/
 	void*	buf,	/* in: block to be freed, must not be
 			pointed to by the buffer pool */
-	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE */
 	__attribute__((nonnull));
 
 #ifndef UNIV_NONINL

include/buf0buddy.ic

@@ -25,7 +25,8 @@ void*
 buf_buddy_alloc_low(
 /*================*/
 			/* out: pointer to the start of the block */
-	ulint	i,	/* in: index of buf_pool->zip_free[] */
+	ulint	i,	/* in: index of buf_pool->zip_free[],
+			or BUF_BUDDY_SIZES */
 	ibool	lru)	/* in: TRUE=allocate from the LRU list if needed */
 	__attribute__((malloc));
 
@@ -37,7 +38,8 @@ buf_buddy_free_low(
 /*===============*/
 	void*	buf,	/* in: block to be freed, must not be
 			pointed to by the buffer pool */
-	ulint	i)	/* in: index of buf_pool->zip_free[] */
+	ulint	i)	/* in: index of buf_pool->zip_free[],
+			or BUF_BUDDY_SIZES */
 	__attribute__((nonnull));
 
 /**************************************************************************
@@ -67,7 +69,8 @@ UNIV_INLINE
 ulint
 buf_buddy_get_slot(
 /*===============*/
-			/* out: index of buf_pool->zip_free[] */
+			/* out: index of buf_pool->zip_free[],
+			or BUF_BUDDY_SIZES */
 	ulint	size)	/* in: block size */
 {
 	ulint	i;
@@ -75,7 +78,7 @@ buf_buddy_get_slot(
 
 	for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1);
 
-	ut_ad(i < BUF_BUDDY_SIZES);
+	ut_ad(i <= BUF_BUDDY_SIZES);
 	return(i);
 }
 
@@ -86,7 +89,7 @@ void*
 buf_buddy_alloc(
 /*============*/
 			/* out: pointer to the start of the block */
-	ulint	size,	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+	ulint	size,	/* in: block size, up to UNIV_PAGE_SIZE */
 	ibool	lru)	/* in: TRUE=allocate from the LRU list if needed */
 {
 #ifdef UNIV_SYNC_DEBUG
@@ -104,7 +107,7 @@ buf_buddy_free(
 /*===========*/
 	void*	buf,	/* in: block to be freed, must not be
 			pointed to by the buffer pool */
-	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE / 2 */
+	ulint	size)	/* in: block size, up to UNIV_PAGE_SIZE */
 {
 #ifdef UNIV_SYNC_DEBUG
 	ut_a(mutex_own(&buf_pool->mutex));

include/buf0buf.h

@@ -70,7 +70,7 @@ enum buf_page_state {
 	BUF_BLOCK_NOT_USED; @see buf_block_state_valid() */
 
 	BUF_BLOCK_NOT_USED,		/* is in the free list */
-	BUF_BLOCK_READY_FOR_USE,	/* when buf_get_free_block returns
+	BUF_BLOCK_READY_FOR_USE,	/* when buf_LRU_get_free_block returns
 					a block, it is in this state */
 	BUF_BLOCK_FILE_PAGE,		/* contains a buffered file page */
 	BUF_BLOCK_MEMORY,		/* contains some main memory object */
@@ -912,8 +912,8 @@ for compressed and uncompressed frames */
 
 struct buf_page_struct{
 	/* None of the following bit-fields must be modified without
-	holding block->mutex or buf_pool->zip_mutex, since they can be
-	stored in the same machine word.  Some of them are
+	holding buf_page_get_mutex() [block->mutex or buf_pool->zip_mutex],
+	since they can be stored in the same machine word.  Some of them are
 	additionally protected by buf_pool->mutex. */
 
 	unsigned	space:32;	/* tablespace id */
@@ -921,7 +921,11 @@ struct buf_page_struct{
 
 	unsigned	state:3;	/* state of the control block
 					(@see enum buf_page_state); also
-					protected by buf_pool->mutex */
+					protected by buf_pool->mutex.
+					State transitions from
+					BUF_BLOCK_READY_FOR_USE to
+					BUF_BLOCK_MEMORY need not be
+					protected by buf_page_get_mutex(). */
 	unsigned	flush_type:2;	/* if this block is currently being
 					flushed to disk, this tells the
 					flush_type (@see enum buf_flush) */