Bug 12635227 - 61188: DROP TABLE EXTREMELY SLOW

approved by: Marko
rb://681

Coalescing of free buf_page_t descriptors can prove to be one severe
bottleneck in performance of compression. One such workload where it
hurts badly is DROP TABLE. This patch removes buf_page_t allocations
from buf_buddy and uses ut_malloc instead.
In order to further reduce overhead of colaescing we no longer attempt
to coalesce a block if the corresponding free_list is less than 16 in
size.

storage/innodb_plugin/ChangeLog

+2011-06-16	The InnoDB Team
+
+	* btr/btr0cur.c, buf/buf0buddy.c, buf/buf0buf.c, buf/buf0lru.c,
+	include/buf0buddy.h, include/buf0buddy.ic, include/buf0buf.h,
+	include/buf0buf.ic, include/buf0lru.h, include/buf0types.h:
+	Fix Bug#61188 DROP TABLE extremely slow
+
 2011-06-16	The InnoDB Team
 
 	* buf/buf0buddy.c, buf/buf0buf.c, buf/buf0flu.c, buf/buf0lru.c,

storage/innodb_plugin/btr/btr0cur.c

@@ -3864,7 +3864,7 @@ btr_blob_free(
 	    && buf_block_get_space(block) == space
 	    && buf_block_get_page_no(block) == page_no) {
 
-		if (buf_LRU_free_block(&block->page, all) != BUF_LRU_FREED
+		if (!buf_LRU_free_block(&block->page, all)
 		    && all && block->page.zip.data) {
 			/* Attempt to deallocate the uncompressed page
 			if the whole block cannot be deallocted. */

storage/innodb_plugin/buf/buf0buddy.c

@@ -45,6 +45,14 @@ static ulint buf_buddy_n_frames;
 Protected by buf_pool_mutex. */
 UNIV_INTERN buf_buddy_stat_t buf_buddy_stat[BUF_BUDDY_SIZES + 1];
 
+/** Validate a given zip_free list. */
+#define BUF_BUDDY_LIST_VALIDATE(i)				\
+	UT_LIST_VALIDATE(list, buf_page_t,			\
+			 buf_pool->zip_free[i],			\
+			 ut_ad(buf_page_get_state(		\
+				       ut_list_node_313)	\
+			       == BUF_BLOCK_ZIP_FREE))
+
 /**********************************************************************//**
 Get the offset of the buddy of a compressed page frame.
 @return	the buddy relative of page */
@@ -76,21 +84,10 @@ buf_buddy_add_to_free(
 	buf_page_t*	bpage,	/*!< in,own: block to be freed */
 	ulint		i)	/*!< in: index of buf_pool->zip_free[] */
 {
-#ifdef UNIV_DEBUG_VALGRIND
-	buf_page_t*	b  = UT_LIST_GET_FIRST(buf_pool->zip_free[i]);
-
-	if (b) UNIV_MEM_VALID(b, BUF_BUDDY_LOW << i);
-#endif /* UNIV_DEBUG_VALGRIND */
-
 	ut_ad(buf_pool_mutex_own());
 	ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_ZIP_FREE);
 	ut_ad(buf_pool->zip_free[i].start != bpage);
 	UT_LIST_ADD_FIRST(list, buf_pool->zip_free[i], bpage);
-
-#ifdef UNIV_DEBUG_VALGRIND
-	if (b) UNIV_MEM_FREE(b, BUF_BUDDY_LOW << i);
-	UNIV_MEM_ASSERT_AND_FREE(bpage, BUF_BUDDY_LOW << i);
-#endif /* UNIV_DEBUG_VALGRIND */
 }
 
 /**********************************************************************//**
@@ -102,25 +99,17 @@ buf_buddy_remove_from_free(
 	buf_page_t*	bpage,	/*!< in: block to be removed */
 	ulint		i)	/*!< in: index of buf_pool->zip_free[] */
 {
-#ifdef UNIV_DEBUG_VALGRIND
+#ifdef UNIV_DEBUG
 	buf_page_t*	prev = UT_LIST_GET_PREV(list, bpage);
 	buf_page_t*	next = UT_LIST_GET_NEXT(list, bpage);
 
-	if (prev) UNIV_MEM_VALID(prev, BUF_BUDDY_LOW << i);
-	if (next) UNIV_MEM_VALID(next, BUF_BUDDY_LOW << i);
-
 	ut_ad(!prev || buf_page_get_state(prev) == BUF_BLOCK_ZIP_FREE);
 	ut_ad(!next || buf_page_get_state(next) == BUF_BLOCK_ZIP_FREE);
-#endif /* UNIV_DEBUG_VALGRIND */
+#endif /* UNIV_DEBUG */
 
 	ut_ad(buf_pool_mutex_own());
 	ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_ZIP_FREE);
 	UT_LIST_REMOVE(list, buf_pool->zip_free[i], bpage);
-
-#ifdef UNIV_DEBUG_VALGRIND
-	if (prev) UNIV_MEM_FREE(prev, BUF_BUDDY_LOW << i);
-	if (next) UNIV_MEM_FREE(next, BUF_BUDDY_LOW << i);
-#endif /* UNIV_DEBUG_VALGRIND */
 }
 
 /**********************************************************************//**
@@ -136,17 +125,13 @@ buf_buddy_alloc_zip(
 
 	ut_ad(buf_pool_mutex_own());
 	ut_a(i < BUF_BUDDY_SIZES);
+	ut_a(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
+
+	ut_d(BUF_BUDDY_LIST_VALIDATE(i));
 
-#ifndef UNIV_DEBUG_VALGRIND
-	/* Valgrind would complain about accessing free memory. */
-	ut_d(UT_LIST_VALIDATE(list, buf_page_t, buf_pool->zip_free[i],
-			      ut_ad(buf_page_get_state(ut_list_node_313)
-				    == BUF_BLOCK_ZIP_FREE)));
-#endif /* !UNIV_DEBUG_VALGRIND */
 	bpage = UT_LIST_GET_FIRST(buf_pool->zip_free[i]);
 
 	if (bpage) {
-		UNIV_MEM_VALID(bpage, BUF_BUDDY_LOW << i);
 		ut_a(buf_page_get_state(bpage) == BUF_BLOCK_ZIP_FREE);
 
 		buf_buddy_remove_from_free(bpage, i);
@@ -165,13 +150,10 @@ buf_buddy_alloc_zip(
 		}
 	}
 
-#ifdef UNIV_DEBUG
 	if (bpage) {
-		memset(bpage, ~i, BUF_BUDDY_LOW << i);
+		ut_d(memset(bpage, ~i, BUF_BUDDY_LOW << i));
+		UNIV_MEM_ALLOC(bpage, BUF_BUDDY_SIZES << i);
 	}
-#endif /* UNIV_DEBUG */
-
-	UNIV_MEM_ALLOC(bpage, BUF_BUDDY_SIZES << i);
 
 	return(bpage);
 }
@@ -255,6 +237,7 @@ buf_buddy_alloc_from(
 {
 	ulint	offs	= BUF_BUDDY_LOW << j;
 	ut_ad(j <= BUF_BUDDY_SIZES);
+	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
 	ut_ad(j >= i);
 	ut_ad(!ut_align_offset(buf, offs));
 
@@ -268,13 +251,7 @@ buf_buddy_alloc_from(
 		bpage = (buf_page_t*) ((byte*) buf + offs);
 		ut_d(memset(bpage, j, BUF_BUDDY_LOW << j));
 		bpage->state = BUF_BLOCK_ZIP_FREE;
-#ifndef UNIV_DEBUG_VALGRIND
-		/* Valgrind would complain about accessing free memory. */
-		ut_d(UT_LIST_VALIDATE(list, buf_page_t, buf_pool->zip_free[i],
-				      ut_ad(buf_page_get_state(
-						    ut_list_node_313)
-					    == BUF_BLOCK_ZIP_FREE)));
-#endif /* !UNIV_DEBUG_VALGRIND */
+		ut_d(BUF_BUDDY_LIST_VALIDATE(i));
 		buf_buddy_add_to_free(bpage, j);
 	}
 
@@ -284,8 +261,8 @@ buf_buddy_alloc_from(
 /**********************************************************************//**
 Allocate a block.  The thread calling this function must hold
 buf_pool_mutex and must not hold buf_pool_zip_mutex or any block->mutex.
-The buf_pool_mutex may only be released and reacquired if lru != NULL.
-@return	allocated block, possibly NULL if lru==NULL */
+The buf_pool_mutex may be released and reacquired.
+@return	allocated block, never NULL */
 UNIV_INTERN
 void*
 buf_buddy_alloc_low(
@@ -294,13 +271,14 @@ buf_buddy_alloc_low(
 			or BUF_BUDDY_SIZES */
 	ibool*	lru)	/*!< in: pointer to a variable that will be assigned
 			TRUE if storage was allocated from the LRU list
-			and buf_pool_mutex was temporarily released,
-			or NULL if the LRU list should not be used */
+			and buf_pool_mutex was temporarily released */
 {
 	buf_block_t*	block;
 
+	ut_ad(lru);
 	ut_ad(buf_pool_mutex_own());
 	ut_ad(!mutex_own(&buf_pool_zip_mutex));
+	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
 
 	if (i < BUF_BUDDY_SIZES) {
 		/* Try to allocate from the buddy system. */
@@ -320,11 +298,6 @@ buf_buddy_alloc_low(
 		goto alloc_big;
 	}
 
-	if (!lru) {
-
-		return(NULL);
-	}
-
 	/* Try replacing an uncompressed page in the buffer pool. */
 	buf_pool_mutex_exit();
 	block = buf_LRU_get_free_block();
@@ -341,65 +314,6 @@ func_exit:
 	return(block);
 }
 
-/**********************************************************************//**
-Try to relocate the control block of a compressed page.
-@return	TRUE if relocated */
-static
-ibool
-buf_buddy_relocate_block(
-/*=====================*/
-	buf_page_t*	bpage,	/*!< in: block to relocate */
-	buf_page_t*	dpage)	/*!< in: free block to relocate to */
-{
-#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
-	buf_page_t*	b;
-#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
-
-	ut_ad(buf_pool_mutex_own());
-
-	switch (buf_page_get_state(bpage)) {
-	case BUF_BLOCK_ZIP_FREE:
-	case BUF_BLOCK_NOT_USED:
-	case BUF_BLOCK_READY_FOR_USE:
-	case BUF_BLOCK_FILE_PAGE:
-	case BUF_BLOCK_MEMORY:
-	case BUF_BLOCK_REMOVE_HASH:
-		ut_error;
-	case BUF_BLOCK_ZIP_DIRTY:
-		/* Cannot relocate dirty pages. */
-		return(FALSE);
-
-	case BUF_BLOCK_ZIP_PAGE:
-		break;
-	}
-
-	mutex_enter(&buf_pool_zip_mutex);
-
-	if (!buf_page_can_relocate(bpage)) {
-		mutex_exit(&buf_pool_zip_mutex);
-		return(FALSE);
-	}
-
-	buf_relocate(bpage, dpage);
-	ut_d(bpage->state = BUF_BLOCK_ZIP_FREE);
-#if defined UNIV_DEBUG || defined UNIV_BUF_DEBUG
-	/* relocate buf_pool->zip_clean */
-	b = UT_LIST_GET_PREV(list, dpage);
-	UT_LIST_REMOVE(list, buf_pool->zip_clean, dpage);
-
-	if (b) {
-		UT_LIST_INSERT_AFTER(list, buf_pool->zip_clean, b, dpage);
-	} else {
-		UT_LIST_ADD_FIRST(list, buf_pool->zip_clean, dpage);
-	}
-#endif /* UNIV_DEBUG || UNIV_BUF_DEBUG */
-
-	UNIV_MEM_INVALID(bpage, sizeof *bpage);
-
-	mutex_exit(&buf_pool_zip_mutex);
-	return(TRUE);
-}
-
 /**********************************************************************//**
 Try to relocate a block.
 @return	TRUE if relocated */
@@ -414,106 +328,89 @@ buf_buddy_relocate(
 	buf_page_t*	bpage;
 	const ulint	size	= BUF_BUDDY_LOW << i;
 	ullint		usec	= ut_time_us(NULL);
+	mutex_t*	mutex;
+	ulint		space;
+	ulint		page_no;
 
 	ut_ad(buf_pool_mutex_own());
 	ut_ad(!mutex_own(&buf_pool_zip_mutex));
 	ut_ad(!ut_align_offset(src, size));
 	ut_ad(!ut_align_offset(dst, size));
+	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
 	UNIV_MEM_ASSERT_W(dst, size);
 
 	/* We assume that all memory from buf_buddy_alloc()
-	is used for either compressed pages or buf_page_t
-	objects covering compressed pages. */
+	is used for compressed page frames. */
 
 	/* We look inside the allocated objects returned by
-	buf_buddy_alloc() and assume that anything of
-	PAGE_ZIP_MIN_SIZE or larger is a compressed page that contains
-	a valid space_id and page_no in the page header.  Should the
-	fields be invalid, we will be unable to relocate the block.
-	We also assume that anything that fits sizeof(buf_page_t)
-	actually is a properly initialized buf_page_t object. */
-
-	if (size >= PAGE_ZIP_MIN_SIZE) {
-		/* This is a compressed page. */
-		mutex_t*	mutex;
-
-		/* The src block may be split into smaller blocks,
-		some of which may be free.  Thus, the
-		mach_read_from_4() calls below may attempt to read
-		from free memory.  The memory is "owned" by the buddy
-		allocator (and it has been allocated from the buffer
-		pool), so there is nothing wrong about this.  The
-		mach_read_from_4() calls here will only trigger bogus
-		Valgrind memcheck warnings in UNIV_DEBUG_VALGRIND builds. */
-		ulint		space	= mach_read_from_4(
-			(const byte*) src + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
-		ulint		page_no	= mach_read_from_4(
-			(const byte*) src + FIL_PAGE_OFFSET);
-		/* Suppress Valgrind warnings about conditional jump
-		on uninitialized value. */
-		UNIV_MEM_VALID(&space, sizeof space);
-		UNIV_MEM_VALID(&page_no, sizeof page_no);
-		bpage = buf_page_hash_get(space, page_no);
-
-		if (!bpage || bpage->zip.data != src) {
-			/* The block has probably been freshly
-			allocated by buf_LRU_get_free_block() but not
-			added to buf_pool->page_hash yet.  Obviously,
-			it cannot be relocated. */
-
-			return(FALSE);
-		}
+	buf_buddy_alloc() and assume that each block is a compressed
+	page that contains a valid space_id and page_no in the page
+	header. Should the fields be invalid, we will be unable to
+	relocate the block. */
+
+	/* The src block may be split into smaller blocks,
+	some of which may be free.  Thus, the
+	mach_read_from_4() calls below may attempt to read
+	from free memory.  The memory is "owned" by the buddy
+	allocator (and it has been allocated from the buffer
+	pool), so there is nothing wrong about this.  The
+	mach_read_from_4() calls here will only trigger bogus
+	Valgrind memcheck warnings in UNIV_DEBUG_VALGRIND builds. */
+	space	= mach_read_from_4((const byte *) src
+			+ FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID);
+	page_no	= mach_read_from_4((const byte *) src
+			+ FIL_PAGE_OFFSET);
+	/* Suppress Valgrind warnings about conditional jump
+	on uninitialized value. */
+	UNIV_MEM_VALID(&space, sizeof space);
+	UNIV_MEM_VALID(&page_no, sizeof page_no);
+	bpage = buf_page_hash_get(space, page_no);
+
+	if (!bpage || bpage->zip.data != src) {
+		/* The block has probably been freshly
+		allocated by buf_LRU_get_free_block() but not
+		added to buf_pool->page_hash yet.  Obviously,
+		it cannot be relocated. */
 
-		if (page_zip_get_size(&bpage->zip) != size) {
-			/* The block is of different size.  We would
-			have to relocate all blocks covered by src.
-			For the sake of simplicity, give up. */
-			ut_ad(page_zip_get_size(&bpage->zip) < size);
+		return(FALSE);
+	}
 
-			return(FALSE);
-		}
+	if (page_zip_get_size(&bpage->zip) != size) {
+		/* The block is of different size.  We would
+		have to relocate all blocks covered by src.
+		For the sake of simplicity, give up. */
+		ut_ad(page_zip_get_size(&bpage->zip) < size);
 
-		/* The block must have been allocated, but it may
-		contain uninitialized data. */
-		UNIV_MEM_ASSERT_W(src, size);
-
-		mutex = buf_page_get_mutex(bpage);
-
-		mutex_enter(mutex);
-
-		if (buf_page_can_relocate(bpage)) {
-			/* Relocate the compressed page. */
-			ut_a(bpage->zip.data == src);
-			memcpy(dst, src, size);
-			bpage->zip.data = dst;
-			mutex_exit(mutex);
-success:
-			UNIV_MEM_INVALID(src, size);
-			{
-				buf_buddy_stat_t*	buddy_stat
-					= &buf_buddy_stat[i];
-				buddy_stat->relocated++;
-				buddy_stat->relocated_usec
-					+= ut_time_us(NULL) - usec;
-			}
-			return(TRUE);
-		}
+		return(FALSE);
+	}
 
-		mutex_exit(mutex);
-	} else if (i == buf_buddy_get_slot(sizeof(buf_page_t))) {
-		/* This must be a buf_page_t object. */
-#if UNIV_WORD_SIZE == 4
-		/* On 32-bit systems, there is no padding in
-		buf_page_t.  On other systems, Valgrind could complain
-		about uninitialized pad bytes. */
-		UNIV_MEM_ASSERT_RW(src, size);
-#endif
-		if (buf_buddy_relocate_block(src, dst)) {
+	/* The block must have been allocated, but it may
+	contain uninitialized data. */
+	UNIV_MEM_ASSERT_W(src, size);
+
+	mutex = buf_page_get_mutex(bpage);
+
+	mutex_enter(mutex);
 
-			goto success;
+	if (buf_page_can_relocate(bpage)) {
+		/* Relocate the compressed page. */
+		ut_a(bpage->zip.data == src);
+		memcpy(dst, src, size);
+		bpage->zip.data = dst;
+		mutex_exit(mutex);
+		UNIV_MEM_INVALID(src, size);
+		{
+			buf_buddy_stat_t*	buddy_stat
+				= &buf_buddy_stat[i];
+			buddy_stat->relocated++;
+			buddy_stat->relocated_usec
+				+= ut_time_us(NULL) - usec;
 		}
+		return(TRUE);
 	}
 
+	mutex_exit(mutex);
+
 	return(FALSE);
 }
 
@@ -534,12 +431,14 @@ buf_buddy_free_low(
 	ut_ad(buf_pool_mutex_own());
 	ut_ad(!mutex_own(&buf_pool_zip_mutex));
 	ut_ad(i <= BUF_BUDDY_SIZES);
+	ut_ad(i >= buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE));
 	ut_ad(buf_buddy_stat[i].used > 0);
 
 	buf_buddy_stat[i].used--;
+
 recombine:
 	UNIV_MEM_ASSERT_AND_ALLOC(buf, BUF_BUDDY_LOW << i);
-	ut_d(((buf_page_t*) buf)->state = BUF_BLOCK_ZIP_FREE);
+	((buf_page_t*) buf)->state = BUF_BLOCK_ZIP_FREE;
 
 	if (i == BUF_BUDDY_SIZES) {
 		buf_buddy_block_free(buf);
@@ -550,32 +449,36 @@ recombine:
 	ut_ad(buf == ut_align_down(buf, BUF_BUDDY_LOW << i));
 	ut_ad(!buf_pool_contains_zip(buf));
 
-	/* Try to combine adjacent blocks. */
+	/* Do not recombine blocks if there are few free blocks.
+	We may waste up to 15360*max_len bytes to free blocks
+	(1024 + 2048 + 4096 + 8192 = 15360) */
+	if (UT_LIST_GET_LEN(buf_pool->zip_free[i]) < 16) {
+		goto func_exit;
+	}
 
+	/* Try to combine adjacent blocks. */
 	buddy = (buf_page_t*) buf_buddy_get(((byte*) buf), BUF_BUDDY_LOW << i);
 
 #ifndef UNIV_DEBUG_VALGRIND
-	/* Valgrind would complain about accessing free memory. */
+	/* When Valgrind instrumentation is not enabled, we can read
+	buddy->state to quickly determine that a block is not free.
+	When the block is not free, buddy->state belongs to a compressed
+	page frame that may be flagged uninitialized in our Valgrind
+	instrumentation.  */
 
 	if (buddy->state != BUF_BLOCK_ZIP_FREE) {
 
 		goto buddy_nonfree;
 	}
-
-	/* The field buddy->state can only be trusted for free blocks.
-	If buddy->state == BUF_BLOCK_ZIP_FREE, the block is free if
-	it is in the free list. */
 #endif /* !UNIV_DEBUG_VALGRIND */
 
 	for (bpage = UT_LIST_GET_FIRST(buf_pool->zip_free[i]); bpage; ) {
-		UNIV_MEM_VALID(bpage, BUF_BUDDY_LOW << i);
 		ut_ad(buf_page_get_state(bpage) == BUF_BLOCK_ZIP_FREE);
 
 		if (bpage == buddy) {
-buddy_free:
 			/* The buddy is free: recombine */
 			buf_buddy_remove_from_free(bpage, i);
-buddy_free2:
+buddy_is_free:
 			ut_ad(buf_page_get_state(buddy) == BUF_BLOCK_ZIP_FREE);
 			ut_ad(!buf_pool_contains_zip(buddy));
 			i++;
@@ -585,122 +488,43 @@ buddy_free2:
 		}
 
 		ut_a(bpage != buf);
-
-		{
-			buf_page_t*	next = UT_LIST_GET_NEXT(list, bpage);
-			UNIV_MEM_ASSERT_AND_FREE(bpage, BUF_BUDDY_LOW << i);
-			bpage = next;
-		}
+		UNIV_MEM_ASSERT_W(bpage, BUF_BUDDY_LOW << i);
+		bpage = UT_LIST_GET_NEXT(list, bpage);
 	}
 
 #ifndef UNIV_DEBUG_VALGRIND
 buddy_nonfree:
-	/* Valgrind would complain about accessing free memory. */
-	ut_d(UT_LIST_VALIDATE(list, buf_page_t, buf_pool->zip_free[i],
-			      ut_ad(buf_page_get_state(ut_list_node_313)
-				    == BUF_BLOCK_ZIP_FREE)));
-#endif /* UNIV_DEBUG_VALGRIND */
+#endif /* !UNIV_DEBUG_VALGRIND */
+
+	ut_d(BUF_BUDDY_LIST_VALIDATE(i));
 
 	/* The buddy is not free. Is there a free block of this size? */
 	bpage = UT_LIST_GET_FIRST(buf_pool->zip_free[i]);
 
 	if (bpage) {
+
 		/* Remove the block from the free list, because a successful
 		buf_buddy_relocate() will overwrite bpage->list. */
-
-		UNIV_MEM_VALID(bpage, BUF_BUDDY_LOW << i);
 		buf_buddy_remove_from_free(bpage, i);
 
 		/* Try to relocate the buddy of buf to the free block. */
 		if (buf_buddy_relocate(buddy, bpage, i)) {
 
-			ut_d(buddy->state = BUF_BLOCK_ZIP_FREE);
-			goto buddy_free2;
+			buddy->state = BUF_BLOCK_ZIP_FREE;
+			goto buddy_is_free;
 		}
 
 		buf_buddy_add_to_free(bpage, i);
-
-		/* Try to relocate the buddy of the free block to buf. */
-		buddy = (buf_page_t*) buf_buddy_get(((byte*) bpage),
-						    BUF_BUDDY_LOW << i);
-
-#ifndef UNIV_DEBUG_VALGRIND
-		/* Valgrind would complain about accessing free memory. */
-
-		/* The buddy must not be (completely) free, because we
-		always recombine adjacent free blocks.
-
-		(Parts of the buddy can be free in
-		buf_pool->zip_free[j] with j < i.) */
-		ut_d(UT_LIST_VALIDATE(list, buf_page_t, buf_pool->zip_free[i],
-				      ut_ad(buf_page_get_state(
-						    ut_list_node_313)
-					    == BUF_BLOCK_ZIP_FREE
-					    && ut_list_node_313 != buddy)));
-#endif /* !UNIV_DEBUG_VALGRIND */
-
-		if (buf_buddy_relocate(buddy, buf, i)) {
-
-			buf = bpage;
-			UNIV_MEM_VALID(bpage, BUF_BUDDY_LOW << i);
-			ut_d(buddy->state = BUF_BLOCK_ZIP_FREE);
-			goto buddy_free;
-		}
 	}
 
+func_exit:
 	/* Free the block to the buddy list. */
 	bpage = buf;
-#ifdef UNIV_DEBUG
-	if (i < buf_buddy_get_slot(PAGE_ZIP_MIN_SIZE)) {
-		/* This area has most likely been allocated for at
-		least one compressed-only block descriptor.  Check
-		that there are no live objects in the area.  This is
-		not a complete check: it may yield false positives as
-		well as false negatives.  Also, due to buddy blocks
-		being recombined, it is possible (although unlikely)
-		that this branch is never reached. */
-
-		char* c;
-
-# ifndef UNIV_DEBUG_VALGRIND
-		/* Valgrind would complain about accessing
-		uninitialized memory.  Besides, Valgrind performs a
-		more exhaustive check, at every memory access. */
-		const buf_page_t* b = buf;
-		const buf_page_t* const b_end = (buf_page_t*)
-			((char*) b + (BUF_BUDDY_LOW << i));
-
-		for (; b < b_end; b++) {
-			/* Avoid false positives (and cause false
-			negatives) by checking for b->space < 1000. */
-
-			if ((b->state == BUF_BLOCK_ZIP_PAGE
-			     || b->state == BUF_BLOCK_ZIP_DIRTY)
-			    && b->space > 0 && b->space < 1000) {
-				fprintf(stderr,
-					"buddy dirty %p %u (%u,%u) %p,%lu\n",
-					(void*) b,
-					b->state, b->space, b->offset,
-					buf, i);
-			}
-		}
-# endif /* !UNIV_DEBUG_VALGRIND */
-
-		/* Scramble the block.  This should make any pointers
-		invalid and trigger a segmentation violation.  Because
-		the scrambling can be reversed, it may be possible to
-		track down the object pointing to the freed data by
-		dereferencing the unscrambled bpage->LRU or
-		bpage->list pointers. */
-		for (c = (char*) buf + (BUF_BUDDY_LOW << i);
-		     c-- > (char*) buf; ) {
-			*c = ~*c ^ i;
-		}
-	} else {
-		/* Fill large blocks with a constant pattern. */
-		memset(bpage, i, BUF_BUDDY_LOW << i);
-	}
-#endif /* UNIV_DEBUG */
+
+	/* Fill large blocks with a constant pattern. */
+	ut_d(memset(bpage, i, BUF_BUDDY_LOW << i));
+	UNIV_MEM_INVALID(bpage, BUF_BUDDY_LOW << i);
+
 	bpage->state = BUF_BLOCK_ZIP_FREE;
 	buf_buddy_add_to_free(bpage, i);
 }

storage/innodb_plugin/buf/buf0buf.c

@@ -1358,7 +1358,7 @@ err_exit:
 		mutex_enter(block_mutex);
 
 		/* Discard the uncompressed page frame if possible. */
-		if (buf_LRU_free_block(bpage, FALSE) == BUF_LRU_FREED) {
+		if (buf_LRU_free_block(bpage, FALSE)) {
 
 			mutex_exit(block_mutex);
 			goto lookup;
@@ -1699,13 +1699,8 @@ loop:
 
 	if (block) {
 		/* If the guess is a compressed page descriptor that
-		has been allocated by buf_buddy_alloc(), it may have
-		been invalidated by buf_buddy_relocate().  In that
-		case, block could point to something that happens to
-		contain the expected bits in block->page.  Similarly,
-		the guess may be pointing to a buffer pool chunk that
-		has been released when resizing the buffer pool. */
-
+		has been allocated by buf_page_alloc_descriptor(),
+		it may have been freed by buf_relocate(). */
 		if (!buf_block_is_uncompressed(block)
 		    || offset != block->page.offset
 		    || space != block->page.space
@@ -1889,11 +1884,10 @@ wait_until_unfixed:
 		mutex_exit(&buf_pool_zip_mutex);
 		buf_pool->n_pend_unzip++;
 
-		bpage->state = BUF_BLOCK_ZIP_FREE;
-		buf_buddy_free(bpage, sizeof *bpage);
-
 		buf_pool_mutex_exit();
 
+		buf_page_free_descriptor(bpage);
+
 		/* Decompress the page and apply buffered operations
 		while not holding buf_pool_mutex or block->mutex. */
 		success = buf_zip_decompress(block, srv_use_checksums);
@@ -1937,7 +1931,7 @@ wait_until_unfixed:
 		/* Try to evict the block from the buffer pool, to use the
 		insert buffer as much as possible. */
 
-		if (buf_LRU_free_block(&block->page, TRUE) == BUF_LRU_FREED) {
+		if (buf_LRU_free_block(&block->page, TRUE)) {
 			buf_pool_mutex_exit();
 			mutex_exit(&block->mutex);
 			fprintf(stderr,
@@ -2551,17 +2545,12 @@ err_exit:
 
 		mutex_exit(&block->mutex);
 	} else {
-		/* Defer buf_buddy_alloc() until after the block has
-		been found not to exist.  The buf_buddy_alloc() and
-		buf_buddy_free() calls may be expensive because of
-		buf_buddy_relocate(). */
 
 		/* The compressed page must be allocated before the
 		control block (bpage), in order to avoid the
 		invocation of buf_buddy_relocate_block() on
 		uninitialized data. */
 		data = buf_buddy_alloc(zip_size, &lru);
-		bpage = buf_buddy_alloc(sizeof *bpage, &lru);
 
 		/* If buf_buddy_alloc() allocated storage from the LRU list,
 		it released and reacquired buf_pool_mutex.  Thus, we must
@@ -2569,15 +2558,13 @@ err_exit:
 		if (UNIV_UNLIKELY(lru)
 		    && UNIV_LIKELY_NULL(buf_page_hash_get(space, offset))) {
 
-			/* The block was added by some other thread. */
-			bpage->state = BUF_BLOCK_ZIP_FREE;
-			buf_buddy_free(bpage, sizeof *bpage);
 			buf_buddy_free(data, zip_size);
-
 			bpage = NULL;
 			goto func_exit;
 		}
 
+		bpage = buf_page_alloc_descriptor();
+
 		page_zip_des_init(&bpage->zip);
 		page_zip_set_size(&bpage->zip, zip_size);
 		bpage->zip.data = data;

storage/innodb_plugin/buf/buf0lru.c

@@ -355,7 +355,7 @@ scan_again:
 
 	while (bpage != NULL) {
 		buf_page_t*	prev_bpage;
-		ibool		prev_bpage_buf_fix = FALSE;
+		mutex_t*	block_mutex = NULL;
 
 		ut_a(buf_page_in_file(bpage));
 
@@ -368,18 +368,21 @@ scan_again:
 		if (buf_page_get_space(bpage) != id) {
 			/* Skip this block, as it does not belong to
 			the space that is being invalidated. */
+			goto next_page;
 		} else if (buf_page_get_io_fix(bpage) != BUF_IO_NONE) {
 			/* We cannot remove this page during this scan
 			yet; maybe the system is currently reading it
 			in, or flushing the modifications to the file */
 
 			all_freed = FALSE;
+			goto next_page;
 		} else {
-			mutex_t* block_mutex = buf_page_get_mutex(bpage);
+			block_mutex = buf_page_get_mutex(bpage);
 			mutex_enter(block_mutex);
 
 			if (bpage->buf_fix_count > 0) {
 
+				mutex_exit(block_mutex);
 				/* We cannot remove this page during
 				this scan yet; maybe the system is
 				currently reading it in, or flushing
@@ -389,106 +392,59 @@ scan_again:
 
 				goto next_page;
 			}
+		}
+
+		ut_ad(mutex_own(block_mutex));
 
 #ifdef UNIV_DEBUG
-			if (buf_debug_prints) {
-				fprintf(stderr,
-					"Dropping space %lu page %lu\n",
-					(ulong) buf_page_get_space(bpage),
-					(ulong) buf_page_get_page_no(bpage));
-			}
+		if (buf_debug_prints) {
+			fprintf(stderr,
+				"Dropping space %lu page %lu\n",
+				(ulong) buf_page_get_space(bpage),
+				(ulong) buf_page_get_page_no(bpage));
+		}
 #endif
-			if (buf_page_get_state(bpage) != BUF_BLOCK_FILE_PAGE) {
-				/* This is a compressed-only block
-				descriptor.  Ensure that prev_bpage
-				cannot be relocated when bpage is freed. */
-				if (UNIV_LIKELY(prev_bpage != NULL)) {
-					switch (buf_page_get_state(
-							prev_bpage)) {
-					case BUF_BLOCK_FILE_PAGE:
-						/* Descriptors of uncompressed
-						blocks will not be relocated,
-						because we are holding the
-						buf_pool_mutex. */
-						break;
-					case BUF_BLOCK_ZIP_PAGE:
-					case BUF_BLOCK_ZIP_DIRTY:
-						/* Descriptors of compressed-
-						only blocks can be relocated,
-						unless they are buffer-fixed.
-						Because both bpage and
-						prev_bpage are protected by
-						buf_pool_zip_mutex, it is
-						not necessary to acquire
-						further mutexes. */
-						ut_ad(&buf_pool_zip_mutex
-						      == block_mutex);
-						ut_ad(mutex_own(block_mutex));
-						prev_bpage_buf_fix = TRUE;
-						prev_bpage->buf_fix_count++;
-						break;
-					default:
-						ut_error;
-					}
-				}
-			} else if (((buf_block_t*) bpage)->is_hashed) {
-				ulint	page_no;
-				ulint	zip_size;
-
-				buf_pool_mutex_exit();
+		if (buf_page_get_state(bpage) != BUF_BLOCK_FILE_PAGE) {
+			/* This is a compressed-only block
+			descriptor. Do nothing. */
+		} else if (((buf_block_t*) bpage)->is_hashed) {
+			ulint	page_no;
+			ulint	zip_size;
 
-				zip_size = buf_page_get_zip_size(bpage);
-				page_no = buf_page_get_page_no(bpage);
+			buf_pool_mutex_exit();
 
-				mutex_exit(block_mutex);
+			zip_size = buf_page_get_zip_size(bpage);
+			page_no = buf_page_get_page_no(bpage);
 
-				/* Note that the following call will acquire
-				an S-latch on the page */
+			mutex_exit(block_mutex);
 
-				btr_search_drop_page_hash_when_freed(
-					id, zip_size, page_no);
-				goto scan_again;
-			}
+			/* Note that the following call will acquire
+			an S-latch on the page */
 
-			if (bpage->oldest_modification != 0) {
+			btr_search_drop_page_hash_when_freed(
+				id, zip_size, page_no);
+			goto scan_again;
+		}
 
-				buf_flush_remove(bpage);
-			}
+		if (bpage->oldest_modification != 0) {
 
-			/* Remove from the LRU list. */
+			buf_flush_remove(bpage);
+		}
 
-			if (buf_LRU_block_remove_hashed_page(bpage, TRUE)
-			    != BUF_BLOCK_ZIP_FREE) {
-				buf_LRU_block_free_hashed_page((buf_block_t*)
-							       bpage);
-			} else {
-				/* The block_mutex should have been
-				released by buf_LRU_block_remove_hashed_page()
-				when it returns BUF_BLOCK_ZIP_FREE. */
-				ut_ad(block_mutex == &buf_pool_zip_mutex);
-				ut_ad(!mutex_own(block_mutex));
-
-				if (prev_bpage_buf_fix) {
-					/* We temporarily buffer-fixed
-					prev_bpage, so that
-					buf_buddy_free() could not
-					relocate it, in case it was a
-					compressed-only block
-					descriptor. */
-
-					mutex_enter(block_mutex);
-					ut_ad(prev_bpage->buf_fix_count > 0);
-					prev_bpage->buf_fix_count--;
-					mutex_exit(block_mutex);
-				}
+		/* Remove from the LRU list. */
 
-				goto next_page_no_mutex;
-			}
-next_page:
+		if (buf_LRU_block_remove_hashed_page(bpage, TRUE)
+		    != BUF_BLOCK_ZIP_FREE) {
+			buf_LRU_block_free_hashed_page((buf_block_t*) bpage);
 			mutex_exit(block_mutex);
+		} else {
+			/* The block_mutex should have been released
+			by buf_LRU_block_remove_hashed_page() when it
+			returns BUF_BLOCK_ZIP_FREE. */
+			ut_ad(block_mutex == &buf_pool_zip_mutex);
+			ut_ad(!mutex_own(block_mutex));
 		}
-
-next_page_no_mutex:
+next_page:
 		bpage = prev_bpage;
 	}
 
@@ -574,7 +530,7 @@ buf_LRU_free_from_unzip_LRU_list(
 	     UNIV_LIKELY(block != NULL) && UNIV_LIKELY(distance > 0);
 	     block = UT_LIST_GET_PREV(unzip_LRU, block), distance--) {
 
-		enum buf_lru_free_block_status	freed;
+		ibool freed;
 
 		ut_ad(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE);
 		ut_ad(block->in_unzip_LRU_list);
@@ -584,24 +540,9 @@ buf_LRU_free_from_unzip_LRU_list(
 		freed = buf_LRU_free_block(&block->page, FALSE);
 		mutex_exit(&block->mutex);
 
-		switch (freed) {
-		case BUF_LRU_FREED:
+		if (freed) {
 			return(TRUE);
-
-		case BUF_LRU_CANNOT_RELOCATE:
-			/* If we failed to relocate, try
-			regular LRU eviction. */
-			return(FALSE);
-
-		case BUF_LRU_NOT_FREED:
-			/* The block was buffer-fixed or I/O-fixed.
-			Keep looking. */
-			continue;
 		}
-
-		/* inappropriate return value from
-		buf_LRU_free_block() */
-		ut_error;
 	}
 
 	return(FALSE);
@@ -632,10 +573,9 @@ buf_LRU_free_from_common_LRU_list(
 	     UNIV_LIKELY(bpage != NULL) && UNIV_LIKELY(distance > 0);
 	     bpage = UT_LIST_GET_PREV(LRU, bpage), distance--) {
 
-		enum buf_lru_free_block_status	freed;
-		unsigned			accessed;
-		mutex_t*			block_mutex
-			= buf_page_get_mutex(bpage);
+		ibool		freed;
+		unsigned	accessed;
+		mutex_t*	block_mutex = buf_page_get_mutex(bpage);
 
 		ut_ad(buf_page_in_file(bpage));
 		ut_ad(bpage->in_LRU_list);
@@ -645,8 +585,7 @@ buf_LRU_free_from_common_LRU_list(
 		freed = buf_LRU_free_block(bpage, TRUE);
 		mutex_exit(block_mutex);
 
-		switch (freed) {
-		case BUF_LRU_FREED:
+		if (freed) {
 			/* Keep track of pages that are evicted without
 			ever being accessed. This gives us a measure of
 			the effectiveness of readahead */
@@ -654,21 +593,7 @@ buf_LRU_free_from_common_LRU_list(
 				++buf_pool->stat.n_ra_pages_evicted;
 			}
 			return(TRUE);
-
-		case BUF_LRU_NOT_FREED:
-			/* The block was dirty, buffer-fixed, or I/O-fixed.
-			Keep looking. */
-			continue;
-
-		case BUF_LRU_CANNOT_RELOCATE:
-			/* This should never occur, because we
-			want to discard the compressed page too. */
-			break;
 		}
-
-		/* inappropriate return value from
-		buf_LRU_free_block() */
-		ut_error;
 	}
 
 	return(FALSE);
@@ -1350,17 +1275,16 @@ buf_LRU_make_block_old(
 Try to free a block.  If bpage is a descriptor of a compressed-only
 page, the descriptor object will be freed as well.
 
-NOTE: If this function returns BUF_LRU_FREED, it will temporarily
+NOTE: If this function returns TRUE, it will temporarily
 release buf_pool_mutex.  Furthermore, the page frame will no longer be
 accessible via bpage.
 
 The caller must hold buf_pool_mutex and buf_page_get_mutex(bpage) and
 release these two mutexes after the call.  No other
 buf_page_get_mutex() may be held when calling this function.
-@return BUF_LRU_FREED if freed, BUF_LRU_CANNOT_RELOCATE or
-BUF_LRU_NOT_FREED otherwise. */
+@return TRUE if freed, FALSE otherwise. */
 UNIV_INTERN
-enum buf_lru_free_block_status
+ibool
 buf_LRU_free_block(
 /*===============*/
 	buf_page_t*	bpage,	/*!< in: block to be freed */
@@ -1385,7 +1309,7 @@ buf_LRU_free_block(
 	if (!buf_page_can_relocate(bpage)) {
 
 		/* Do not free buffer-fixed or I/O-fixed blocks. */
-		return(BUF_LRU_NOT_FREED);
+		return(FALSE);
 	}
 
 #ifdef UNIV_IBUF_COUNT_DEBUG
@@ -1397,7 +1321,7 @@ buf_LRU_free_block(
 		/* Do not completely free dirty blocks. */
 
 		if (bpage->oldest_modification) {
-			return(BUF_LRU_NOT_FREED);
+			return(FALSE);
 		}
 	} else if (bpage->oldest_modification) {
 		/* Do not completely free dirty blocks. */
@@ -1405,7 +1329,7 @@ buf_LRU_free_block(
 		if (buf_page_get_state(bpage) != BUF_BLOCK_FILE_PAGE) {
 			ut_ad(buf_page_get_state(bpage)
 			      == BUF_BLOCK_ZIP_DIRTY);
-			return(BUF_LRU_NOT_FREED);
+			return(FALSE);
 		}
 
 		goto alloc;
@@ -1414,14 +1338,8 @@ buf_LRU_free_block(
 		If it cannot be allocated (without freeing a block
 		from the LRU list), refuse to free bpage. */
 alloc:
-		buf_pool_mutex_exit_forbid();
-		b = buf_buddy_alloc(sizeof *b, NULL);
-		buf_pool_mutex_exit_allow();
-
-		if (UNIV_UNLIKELY(!b)) {
-			return(BUF_LRU_CANNOT_RELOCATE);
-		}
-
+		b = buf_page_alloc_descriptor();
+		ut_a(b);
 		memcpy(b, bpage, sizeof *b);
 	}
 
@@ -1589,7 +1507,7 @@ alloc:
 		mutex_enter(block_mutex);
 	}
 
-	return(BUF_LRU_FREED);
+	return(TRUE);
 }
 
 /******************************************************************//**
@@ -1809,10 +1727,8 @@ buf_LRU_block_remove_hashed_page(
 		buf_pool_mutex_exit_forbid();
 		buf_buddy_free(bpage->zip.data,
 			       page_zip_get_size(&bpage->zip));
-		bpage->state = BUF_BLOCK_ZIP_FREE;
-		buf_buddy_free(bpage, sizeof(*bpage));
 		buf_pool_mutex_exit_allow();
-		UNIV_MEM_UNDESC(bpage);
+		buf_page_free_descriptor(bpage);
 		return(BUF_BLOCK_ZIP_FREE);
 
 	case BUF_BLOCK_FILE_PAGE:

storage/innodb_plugin/include/buf0buddy.h

 /*****************************************************************************
 
-Copyright (c) 2006, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 2006, 2011, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -37,24 +37,19 @@ Created December 2006 by Marko Makela
 /**********************************************************************//**
 Allocate a block.  The thread calling this function must hold
 buf_pool_mutex and must not hold buf_pool_zip_mutex or any
-block->mutex.  The buf_pool_mutex may only be released and reacquired
-if lru != NULL.  This function should only be used for allocating
-compressed page frames or control blocks (buf_page_t).  Allocated
-control blocks must be properly initialized immediately after
-buf_buddy_alloc() has returned the memory, before releasing
-buf_pool_mutex.
-@return	allocated block, possibly NULL if lru == NULL */
+block->mutex.  The buf_pool_mutex may be released and reacquired.
+This function should only be used for allocating compressed page frames.
+@return	allocated block, never NULL */
 UNIV_INLINE
 void*
 buf_buddy_alloc(
 /*============*/
-	ulint	size,	/*!< in: block size, up to UNIV_PAGE_SIZE */
+	ulint	size,	/*!< in: compressed page size
+			(between PAGE_ZIP_MIN_SIZE and UNIV_PAGE_SIZE) */
 	ibool*	lru)	/*!< in: pointer to a variable that will be assigned
 			TRUE if storage was allocated from the LRU list
-			and buf_pool_mutex was temporarily released,
-			or NULL if the LRU list should not be used */
-	__attribute__((malloc));
-
+			and buf_pool_mutex was temporarily released */
+	__attribute__((malloc, nonnull));
 /**********************************************************************//**
 Release a block. */
 UNIV_INLINE

storage/innodb_plugin/include/buf0buddy.ic

 /*****************************************************************************
 
-Copyright (c) 2006, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 2006, 2011, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -36,8 +36,8 @@ Created December 2006 by Marko Makela
 /**********************************************************************//**
 Allocate a block.  The thread calling this function must hold
 buf_pool_mutex and must not hold buf_pool_zip_mutex or any block->mutex.
-The buf_pool_mutex may only be released and reacquired if lru != NULL.
-@return	allocated block, possibly NULL if lru==NULL */
+The buf_pool_mutex may be released and reacquired.
+@return	allocated block, never NULL */
 UNIV_INTERN
 void*
 buf_buddy_alloc_low(
@@ -46,9 +46,8 @@ buf_buddy_alloc_low(
 			or BUF_BUDDY_SIZES */
 	ibool*	lru)	/*!< in: pointer to a variable that will be assigned
 			TRUE if storage was allocated from the LRU list
-			and buf_pool_mutex was temporarily released,
-			or NULL if the LRU list should not be used */
-	__attribute__((malloc));
+			and buf_pool_mutex was temporarily released */
+	__attribute__((malloc, nonnull));
 
 /**********************************************************************//**
 Deallocate a block. */
@@ -74,6 +73,8 @@ buf_buddy_get_slot(
 	ulint	i;
 	ulint	s;
 
+	ut_ad(size >= PAGE_ZIP_MIN_SIZE);
+
 	for (i = 0, s = BUF_BUDDY_LOW; s < size; i++, s <<= 1) {
 	}
 
@@ -84,26 +85,25 @@ buf_buddy_get_slot(
 /**********************************************************************//**
 Allocate a block.  The thread calling this function must hold
 buf_pool_mutex and must not hold buf_pool_zip_mutex or any
-block->mutex.  The buf_pool_mutex may only be released and reacquired
-if lru != NULL.  This function should only be used for allocating
-compressed page frames or control blocks (buf_page_t).  Allocated
-control blocks must be properly initialized immediately after
-buf_buddy_alloc() has returned the memory, before releasing
-buf_pool_mutex.
-@return	allocated block, possibly NULL if lru == NULL */
+block->mutex.  The buf_pool_mutex may be released and reacquired.
+This function should only be used for allocating compressed page frames.
+@return	allocated block, never NULL */
 UNIV_INLINE
 void*
 buf_buddy_alloc(
 /*============*/
-	ulint	size,	/*!< in: block size, up to UNIV_PAGE_SIZE */
+	ulint	size,	/*!< in: compressed page size
+			(between PAGE_ZIP_MIN_SIZE and UNIV_PAGE_SIZE) */
 	ibool*	lru)	/*!< in: pointer to a variable that will be assigned
 			TRUE if storage was allocated from the LRU list
-			and buf_pool_mutex was temporarily released,
-			or NULL if the LRU list should not be used */
+			and buf_pool_mutex was temporarily released */
 {
 	ut_ad(buf_pool_mutex_own());
+	ut_ad(ut_is_2pow(size));
+	ut_ad(size >= PAGE_ZIP_MIN_SIZE);
+	ut_ad(size <= UNIV_PAGE_SIZE);
 
-	return(buf_buddy_alloc_low(buf_buddy_get_slot(size), lru));
+	return((byte*) buf_buddy_alloc_low(buf_buddy_get_slot(size), lru));
 }
 
 /**********************************************************************//**
@@ -117,6 +117,9 @@ buf_buddy_free(
 	ulint	size)	/*!< in: block size, up to UNIV_PAGE_SIZE */
 {
 	ut_ad(buf_pool_mutex_own());
+	ut_ad(ut_is_2pow(size));
+	ut_ad(size >= PAGE_ZIP_MIN_SIZE);
+	ut_ad(size <= UNIV_PAGE_SIZE);
 
 	buf_buddy_free_low(buf, buf_buddy_get_slot(size));
 }

storage/innodb_plugin/include/buf0buf.h

@@ -156,6 +156,23 @@ UNIV_INLINE
 ib_uint64_t
 buf_pool_get_oldest_modification(void);
 /*==================================*/
+/********************************************************************//**
+Allocates a buf_page_t descriptor. This function must succeed. In case
+of failure we assert in this function. */
+UNIV_INLINE
+buf_page_t*
+buf_page_alloc_descriptor(void)
+/*===========================*/
+	__attribute__((malloc));
+/********************************************************************//**
+Free a buf_page_t descriptor. */
+UNIV_INLINE
+void
+buf_page_free_descriptor(
+/*=====================*/
+	buf_page_t*	bpage)	/*!< in: bpage descriptor to free. */
+	__attribute__((nonnull));
+
 /********************************************************************//**
 Allocates a buffer block.
 @return	own: the allocated block, in state BUF_BLOCK_MEMORY */

storage/innodb_plugin/include/buf0buf.ic

@@ -714,6 +714,35 @@ buf_block_get_lock_hash_val(
 	return(block->lock_hash_val);
 }
 
+/********************************************************************//**
+Allocates a buf_page_t descriptor. This function must succeed. In case
+of failure we assert in this function.
+@return: the allocated descriptor. */
+UNIV_INLINE
+buf_page_t*
+buf_page_alloc_descriptor(void)
+/*===========================*/
+{
+	buf_page_t*	bpage;
+
+	bpage = (buf_page_t*) ut_malloc(sizeof *bpage);
+	ut_d(memset(bpage, 0, sizeof *bpage));
+	UNIV_MEM_ALLOC(bpage, sizeof *bpage);
+
+	return(bpage);
+}
+
+/********************************************************************//**
+Free a buf_page_t descriptor. */
+UNIV_INLINE
+void
+buf_page_free_descriptor(
+/*=====================*/
+	buf_page_t*	bpage)	/*!< in: bpage descriptor to free. */
+{
+	ut_free(bpage);
+}
+
 /********************************************************************//**
 Allocates a buffer block.
 @return	own: the allocated block, in state BUF_BLOCK_MEMORY */

storage/innodb_plugin/include/buf0lru.h

@@ -30,18 +30,6 @@ Created 11/5/1995 Heikki Tuuri
 #include "ut0byte.h"
 #include "buf0types.h"
 
-/** The return type of buf_LRU_free_block() */
-enum buf_lru_free_block_status {
-	/** freed */
-	BUF_LRU_FREED = 0,
-	/** not freed because the caller asked to remove the
-	uncompressed frame but the control block cannot be
-	relocated */
-	BUF_LRU_CANNOT_RELOCATE,
-	/** not freed because of some other reason */
-	BUF_LRU_NOT_FREED
-};
-
 /******************************************************************//**
 Tries to remove LRU flushed blocks from the end of the LRU list and put them
 to the free list. This is beneficial for the efficiency of the insert buffer
@@ -98,17 +86,16 @@ buf_LRU_insert_zip_clean(
 Try to free a block.  If bpage is a descriptor of a compressed-only
 page, the descriptor object will be freed as well.
 
-NOTE: If this function returns BUF_LRU_FREED, it will temporarily
+NOTE: If this function returns TRUE, it will temporarily
 release buf_pool_mutex.  Furthermore, the page frame will no longer be
 accessible via bpage.
 
 The caller must hold buf_pool_mutex and buf_page_get_mutex(bpage) and
 release these two mutexes after the call.  No other
 buf_page_get_mutex() may be held when calling this function.
-@return BUF_LRU_FREED if freed, BUF_LRU_CANNOT_RELOCATE or
-BUF_LRU_NOT_FREED otherwise. */
+@return TRUE if freed, FALSE otherwise. */
 UNIV_INTERN
-enum buf_lru_free_block_status
+ibool
 buf_LRU_free_block(
 /*===============*/
 	buf_page_t*	bpage,	/*!< in: block to be freed */

storage/innodb_plugin/include/buf0types.h

 /*****************************************************************************
 
-Copyright (c) 1995, 2009, Innobase Oy. All Rights Reserved.
+Copyright (c) 1995, 2011, Oracle and/or its affiliates. All Rights Reserved
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -26,6 +26,8 @@ Created 11/17/1995 Heikki Tuuri
 #ifndef buf0types_h
 #define buf0types_h
 
+#include "page0types.h"
+
 /** Buffer page (uncompressed or compressed) */
 typedef	struct buf_page_struct		buf_page_t;
 /** Buffer block for which an uncompressed page exists */
@@ -58,17 +60,10 @@ enum buf_io_fix {
 
 /** Parameters of binary buddy system for compressed pages (buf0buddy.h) */
 /* @{ */
-#if UNIV_WORD_SIZE <= 4 /* 32-bit system */
-/** Base-2 logarithm of the smallest buddy block size */
-# define BUF_BUDDY_LOW_SHIFT	6
-#else /* 64-bit system */
-/** Base-2 logarithm of the smallest buddy block size */
-# define BUF_BUDDY_LOW_SHIFT	7
-#endif
+#define BUF_BUDDY_LOW_SHIFT	PAGE_ZIP_MIN_SIZE_SHIFT
+
 #define BUF_BUDDY_LOW		(1 << BUF_BUDDY_LOW_SHIFT)
-					/*!< minimum block size in the binary
-					buddy system; must be at least
-					sizeof(buf_page_t) */
+
 #define BUF_BUDDY_SIZES		(UNIV_PAGE_SIZE_SHIFT - BUF_BUDDY_LOW_SHIFT)
 					/*!< number of buddy sizes */