* The low resource handler now empties the cache depot's magazines; before,

they were never freed unless the cache was destroyed (I just wondered why
  my system would bury >1G in the magazines).
* Made the magazine capacity variable per cache, ie. for larger objects, it's
  not a good idea to have 64*CPU buffers lying around in the worst case.
* Furthermore, the create_object_cache_etc()/object_depot_init() now have
  arguments for the magazine capacity as well as the maximum number of full
  unused magazines.
* By default, you might want to initialize both to zero, as then some hopefully
  usable defaults are computed. Otherwise (the only current example is the
  vm_page_mapping cache) you can just put in the values you'd want there.
  The page mapping cache uses larger values, as its objects are usually
  allocated and deleted in larger chunks.
* Beware, though, I couldn't test these changes yet as Qemu didn't like to run
  today. I'll test these changes on another machine now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35601 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/slab/ObjectDepot.h

@@ -1,4 +1,5 @@
 /*
+ * Copyright 2010, Axel Dörfler. All Rights Reserved.
  * Copyright 2007, Hugo Santos. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
@@ -19,9 +20,11 @@ typedef struct object_depot {
 	DepotMagazine*			empty;
 	size_t					full_count;
 	size_t					empty_count;
+	size_t					max_count;
+	size_t					magazine_capacity;
 	struct depot_cpu_store*	stores;
+	void*					cookie;
 
-	void*	cookie;
 	void (*return_object)(struct object_depot* depot, void* cookie,
 		void* object, uint32 flags);
 } object_depot;
@@ -31,7 +34,8 @@ typedef struct object_depot {
 extern "C" {
 #endif
 
-status_t object_depot_init(object_depot* depot, uint32 flags, void* cookie,
+status_t object_depot_init(object_depot* depot, size_t capacity,
+	size_t maxCount, uint32 flags, void* cookie,
 	void (*returnObject)(object_depot* depot, void* cookie, void* object,
 		uint32 flags));
 void object_depot_destroy(object_depot* depot, uint32 flags);
@@ -45,4 +49,5 @@ void object_depot_make_empty(object_depot* depot, uint32 flags);
 }
 #endif
 
+
 #endif	/* _SLAB_OBJECT_DEPOT_H_ */

headers/private/kernel/slab/Slab.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler. All Rights Reserved.
+ * Copyright 2008-2010, Axel Dörfler. All Rights Reserved.
  * Copyright 2007, Hugo Santos. All Rights Reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -42,11 +42,12 @@ typedef void (*object_cache_reclaimer)(void* cookie, int32 level);
 extern "C" {
 #endif
 
-object_cache* create_object_cache(const char* name, size_t object_size,
+object_cache* create_object_cache(const char* name, size_t objectSize,
 	size_t alignment, void* cookie, object_cache_constructor constructor,
-	object_cache_destructor);
-object_cache* create_object_cache_etc(const char* name, size_t object_size,
-	size_t alignment, size_t max_byte_usage, uint32 flags, void* cookie,
+	object_cache_destructor destructor);
+object_cache* create_object_cache_etc(const char* name, size_t objectSize,
+	size_t alignment, size_t maxByteUsage, size_t magazineCapacity,
+	size_t maxMagazineCount, uint32 flags, void* cookie,
 	object_cache_constructor constructor, object_cache_destructor destructor,
 	object_cache_reclaimer reclaimer);
 

src/system/kernel/cache/block_cache.cpp

@@ -1329,7 +1329,7 @@ block_cache::Init()
 	mutex_init(&lock, "block cache");
 
 	buffer_cache = create_object_cache_etc("block cache buffers", block_size,
-		8, 0, CACHE_LARGE_SLAB, NULL, NULL, NULL, NULL);
+		8, 0, 0, 0, CACHE_LARGE_SLAB, NULL, NULL, NULL, NULL);
 	if (buffer_cache == NULL)
 		return B_NO_MEMORY;
 
@@ -1472,7 +1472,7 @@ block_cache::RemoveUnusedBlocks(int32 maxAccessed, int32 count)
 		if (block->is_dirty && !block->discard) {
 			if (block->busy_writing)
 				continue;
-			
+
 			BlockWriter::WriteBlock(this, block);
 		}
 
@@ -2022,7 +2022,7 @@ dump_block(cached_block* block)
 		(addr_t)block, block->block_number,
 		(addr_t)block->current_data, (addr_t)block->original_data,
 		(addr_t)block->parent_data, block->ref_count, block->accessed,
-		block->busy_reading ? 'r' : '-', block->busy_writing ? 'w' : '-', 
+		block->busy_reading ? 'r' : '-', block->busy_writing ? 'w' : '-',
 		block->is_writing ? 'W' : '-', block->is_dirty ? 'D' : '-',
 		block->unused ? 'U' : '-', block->discard ? 'D' : '-',
 		(addr_t)block->transaction,
@@ -2587,7 +2587,7 @@ status_t
 block_cache_init(void)
 {
 	sBlockCache = create_object_cache_etc("cached blocks", sizeof(cached_block),
-		8, 0, CACHE_LARGE_SLAB, NULL, NULL, NULL, NULL);
+		8, 0, 0, 0, CACHE_LARGE_SLAB, NULL, NULL, NULL, NULL);
 	if (sBlockCache == NULL)
 		return B_NO_MEMORY;
 
@@ -3299,7 +3299,7 @@ block_cache_sync(void* _cache)
 	}
 
 	hash_close(cache->hash, &iterator, false);
-	
+
 	status_t status = writer.Write();
 
 	locker.Unlock();

src/system/kernel/slab/HashedObjectCache.cpp

@@ -51,7 +51,8 @@ HashedObjectCache::HashedObjectCache()
 
 /*static*/ HashedObjectCache*
 HashedObjectCache::Create(const char* name, size_t object_size,
-	size_t alignment, size_t maximum, uint32 flags, void* cookie,
+	size_t alignment, size_t maximum, size_t magazineCapacity,
+	size_t maxMagazineCount, uint32 flags, void* cookie,
 	object_cache_constructor constructor, object_cache_destructor destructor,
 	object_cache_reclaimer reclaimer)
 {
@@ -71,8 +72,9 @@ HashedObjectCache::Create(const char* name, size_t object_size,
 
 	cache->hash_table.Resize(buffer, hashSize, true);
 
-	if (cache->Init(name, object_size, alignment, maximum, flags, cookie,
-			constructor, destructor, reclaimer) != B_OK) {
+	if (cache->Init(name, object_size, alignment, maximum, magazineCapacity,
+			maxMagazineCount, flags, cookie, constructor, destructor,
+			reclaimer) != B_OK) {
 		cache->Delete();
 		return NULL;
 	}

src/system/kernel/slab/HashedObjectCache.h

@@ -24,6 +24,8 @@ struct HashedObjectCache : ObjectCache {
 
 	static	HashedObjectCache*	Create(const char* name, size_t object_size,
 									size_t alignment, size_t maximum,
+									size_t magazineCapacity,
+									size_t maxMagazineCount,
 									uint32 flags, void* cookie,
 									object_cache_constructor constructor,
 									object_cache_destructor destructor,

src/system/kernel/slab/ObjectCache.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler. All Rights Reserved.
+ * Copyright 2008-2010, Axel Dörfler. All Rights Reserved.
  * Copyright 2007, Hugo Santos. All Rights Reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -40,10 +40,10 @@ ObjectCache::~ObjectCache()
 
 
 status_t
-ObjectCache::Init(const char* name, size_t objectSize,
-	size_t alignment, size_t maximum, uint32 flags, void* cookie,
-	object_cache_constructor constructor, object_cache_destructor destructor,
-	object_cache_reclaimer reclaimer)
+ObjectCache::Init(const char* name, size_t objectSize, size_t alignment,
+	size_t maximum, size_t magazineCapacity, size_t maxMagazineCount,
+	uint32 flags, void* cookie, object_cache_constructor constructor,
+	object_cache_destructor destructor, object_cache_reclaimer reclaimer)
 {
 	strlcpy(this->name, name, sizeof(this->name));
 
@@ -86,9 +86,17 @@ ObjectCache::Init(const char* name, size_t objectSize,
 		this->flags |= CACHE_NO_DEPOT;
 
 	if (!(this->flags & CACHE_NO_DEPOT)) {
-		status_t status = object_depot_init(&depot, flags, this,
-			object_cache_return_object_wrapper);
-		if (status < B_OK) {
+		// Determine usable magazine configuration values if none had been given
+		if (magazineCapacity == 0) {
+			magazineCapacity = objectSize < 256
+				? 32 : (objectSize < 512 ? 16 : 8);
+		}
+		if (maxMagazineCount == 0)
+			maxMagazineCount = magazineCapacity / 2;
+
+		status_t status = object_depot_init(&depot, magazineCapacity,
+			maxMagazineCount, flags, this, object_cache_return_object_wrapper);
+		if (status != B_OK) {
 			mutex_destroy(&lock);
 			return status;
 		}

src/system/kernel/slab/ObjectCache.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008, Axel Dörfler. All Rights Reserved.
+ * Copyright 2008-2010, Axel Dörfler. All Rights Reserved.
  * Copyright 2007, Hugo Santos. All Rights Reserved.
  *
  * Distributed under the terms of the MIT License.
@@ -80,7 +80,9 @@ public:
 
 			status_t			Init(const char* name, size_t objectSize,
 									size_t alignment, size_t maximum,
-									uint32 flags, void* cookie,
+									size_t magazineCapacity,
+									size_t maxMagazineCount, uint32 flags,
+									void* cookie,
 									object_cache_constructor constructor,
 									object_cache_destructor destructor,
 									object_cache_reclaimer reclaimer);

src/system/kernel/slab/ObjectDepot.cpp

@@ -19,10 +19,6 @@
 #include "slab_private.h"
 
 
-static const int kMagazineCapacity = 32;
-	// TODO: Should be dynamically tuned per cache.
-
-
 struct DepotMagazine {
 			DepotMagazine*		next;
 			uint16				current_round;
@@ -80,14 +76,15 @@ DepotMagazine::Push(void* object)
 
 
 static DepotMagazine*
-alloc_magazine(uint32 flags)
+alloc_magazine(object_depot* depot, uint32 flags)
 {
 	DepotMagazine* magazine = (DepotMagazine*)slab_internal_alloc(
-		sizeof(DepotMagazine) + kMagazineCapacity * sizeof(void*), flags);
+		sizeof(DepotMagazine) + depot->magazine_capacity * sizeof(void*),
+		flags);
 	if (magazine) {
 		magazine->next = NULL;
 		magazine->current_round = 0;
-		magazine->round_count = kMagazineCapacity;
+		magazine->round_count = depot->magazine_capacity;
 	}
 
 	return magazine;
@@ -113,6 +110,8 @@ empty_magazine(object_depot* depot, DepotMagazine* magazine, uint32 flags)
 static bool
 exchange_with_full(object_depot* depot, DepotMagazine*& magazine)
 {
+	ASSERT(magazine->IsEmpty());
+
 	SpinLocker _(depot->inner_lock);
 
 	if (depot->full == NULL)
@@ -128,8 +127,11 @@ exchange_with_full(object_depot* depot, DepotMagazine*& magazine)
 
 
 static bool
-exchange_with_empty(object_depot* depot, DepotMagazine*& magazine)
+exchange_with_empty(object_depot* depot, DepotMagazine*& magazine,
+	DepotMagazine*& freeMagazine)
 {
+	ASSERT(magazine == NULL || magazine->IsFull());
+
 	SpinLocker _(depot->inner_lock);
 
 	if (depot->empty == NULL)
@@ -137,9 +139,12 @@ exchange_with_empty(object_depot* depot, DepotMagazine*& magazine)
 
 	depot->empty_count--;
 
-	if (magazine) {
-		_push(depot->full, magazine);
-		depot->full_count++;
+	if (magazine != NULL) {
+		if (depot->full_count < depot->max_count) {
+			_push(depot->full, magazine);
+			depot->full_count++;
+		} else
+			freeMagazine = magazine;
 	}
 
 	magazine = _pop(depot->empty);
@@ -168,13 +173,15 @@ object_depot_cpu(object_depot* depot)
 
 
 status_t
-object_depot_init(object_depot* depot, uint32 flags, void* cookie,
-	void (*return_object)(object_depot* depot, void* cookie, void* object,
-		uint32 flags))
+object_depot_init(object_depot* depot, size_t capacity, size_t maxCount,
+	uint32 flags, void* cookie, void (*return_object)(object_depot* depot,
+		void* cookie, void* object, uint32 flags))
 {
 	depot->full = NULL;
 	depot->empty = NULL;
 	depot->full_count = depot->empty_count = 0;
+	depot->max_count = maxCount;
+	depot->magazine_capacity = capacity;
 
 	rw_lock_init(&depot->outer_lock, "object depot");
 	B_INITIALIZE_SPINLOCK(&depot->inner_lock);
@@ -245,6 +252,8 @@ object_depot_obtain(object_depot* depot)
 int
 object_depot_store(object_depot* depot, void* object, uint32 flags)
 {
+	DepotMagazine* freeMagazine = NULL;
+
 	ReadLocker readLocker(depot->outer_lock);
 	InterruptsLocker interruptsLocker;
 
@@ -256,18 +265,31 @@ object_depot_store(object_depot* depot, void* object, uint32 flags)
 	// we return the object directly to the slab.
 
 	while (true) {
-		if (store->loaded && store->loaded->Push(object))
+		if (store->loaded != NULL && store->loaded->Push(object))
 			return 1;
 
-		if ((store->previous && store->previous->IsEmpty())
-			|| exchange_with_empty(depot, store->previous)) {
+		if ((store->previous != NULL && store->previous->IsEmpty())
+			|| exchange_with_empty(depot, store->previous, freeMagazine)) {
 			std::swap(store->loaded, store->previous);
+
+			if (freeMagazine != NULL) {
+				// Free the magazine that didn't have space in the list
+				interruptsLocker.Unlock();
+				readLocker.Unlock();
+
+				empty_magazine(depot, freeMagazine, flags);
+
+				readLocker.Lock();
+				interruptsLocker.Lock();
+
+				store = object_depot_cpu(depot);
+			}
 		} else {
 			// allocate a new empty magazine
 			interruptsLocker.Unlock();
 			readLocker.Unlock();
 
-			DepotMagazine* magazine = alloc_magazine(flags);
+			DepotMagazine* magazine = alloc_magazine(depot, flags);
 			if (magazine == NULL)
 				return 0;
 

src/system/kernel/slab/Slab.cpp

@@ -413,6 +413,11 @@ object_cache_low_memory(void* dummy, uint32 resources, int32 level)
 		if (cache->reclaimer)
 			cache->reclaimer(cache->cookie, level);
 
+		if ((cache->flags & CACHE_NO_DEPOT) == 0) {
+			object_depot_make_empty(&cache->depot, 0);
+				// TODO: what flags?
+		}
+
 		MutexLocker cacheLocker(cache->lock);
 		size_t minimumAllowed;
 
@@ -540,16 +545,16 @@ create_object_cache(const char* name, size_t object_size, size_t alignment,
 	void* cookie, object_cache_constructor constructor,
 	object_cache_destructor destructor)
 {
-	return create_object_cache_etc(name, object_size, alignment, 0, 0, cookie,
-		constructor, destructor, NULL);
+	return create_object_cache_etc(name, object_size, alignment, 0, 0, 0, 0,
+		cookie, constructor, destructor, NULL);
 }
 
 
 object_cache*
 create_object_cache_etc(const char* name, size_t objectSize, size_t alignment,
-	size_t maximum, uint32 flags, void* cookie,
-	object_cache_constructor constructor, object_cache_destructor destructor,
-	object_cache_reclaimer reclaimer)
+	size_t maximum, size_t magazineCapacity, size_t maxMagazineCount,
+	uint32 flags, void* cookie, object_cache_constructor constructor,
+	object_cache_destructor destructor, object_cache_reclaimer reclaimer)
 {
 	ObjectCache* cache;
 
@@ -557,10 +562,12 @@ create_object_cache_etc(const char* name, size_t objectSize, size_t alignment,
 		cache = NULL;
 	} else if (objectSize <= 256) {
 		cache = SmallObjectCache::Create(name, objectSize, alignment, maximum,
-			flags, cookie, constructor, destructor, reclaimer);
+			magazineCapacity, maxMagazineCount, flags, cookie, constructor,
+			destructor, reclaimer);
 	} else {
-		cache = HashedObjectCache::Create(name, objectSize, alignment,
-			maximum, flags, cookie, constructor, destructor, reclaimer);
+		cache = HashedObjectCache::Create(name, objectSize, alignment, maximum,
+			magazineCapacity, maxMagazineCount, flags, cookie, constructor,
+			destructor, reclaimer);
 	}
 
 	if (cache != NULL) {

src/system/kernel/slab/SmallObjectCache.cpp

@@ -21,7 +21,8 @@ slab_in_pages(const void *pages, size_t slab_size)
 
 /*static*/ SmallObjectCache*
 SmallObjectCache::Create(const char* name, size_t object_size,
-	size_t alignment, size_t maximum, uint32 flags, void* cookie,
+	size_t alignment, size_t maximum, size_t magazineCapacity,
+	size_t maxMagazineCount, uint32 flags, void* cookie,
 	object_cache_constructor constructor, object_cache_destructor destructor,
 	object_cache_reclaimer reclaimer)
 {
@@ -31,8 +32,9 @@ SmallObjectCache::Create(const char* name, size_t object_size,
 
 	SmallObjectCache* cache = new(buffer) SmallObjectCache();
 
-	if (cache->Init(name, object_size, alignment, maximum, flags, cookie,
-			constructor, destructor, reclaimer) != B_OK) {
+	if (cache->Init(name, object_size, alignment, maximum, magazineCapacity,
+			maxMagazineCount, flags, cookie, constructor, destructor,
+			reclaimer) != B_OK) {
 		cache->Delete();
 		return NULL;
 	}

src/system/kernel/slab/SmallObjectCache.h

@@ -14,6 +14,8 @@
 struct SmallObjectCache : ObjectCache {
 	static	SmallObjectCache*	Create(const char* name, size_t object_size,
 									size_t alignment, size_t maximum,
+									size_t magazineCapacity,
+									size_t maxMagazineCount,
 									uint32 flags, void* cookie,
 									object_cache_constructor constructor,
 									object_cache_destructor destructor,

src/system/kernel/slab/allocator.cpp

@@ -180,8 +180,8 @@ block_allocator_init_boot()
 		if (size > 2048)
 			flags |= CACHE_NO_DEPOT;
 
-		sBlockCaches[index] = create_object_cache_etc(name, size, 0, 0, flags,
-			NULL, NULL, NULL, NULL);
+		sBlockCaches[index] = create_object_cache_etc(name, size, 0, 0, 0, 0,
+			flags, NULL, NULL, NULL, NULL);
 		if (sBlockCaches[index] == NULL)
 			panic("allocator: failed to init block cache");
 	}

src/system/kernel/vm/vm.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2009-2010, Ingo Weinhold, ingo_weinhold@gmx.de.
- * Copyright 2002-2009, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2010, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -3395,8 +3395,8 @@ vm_init(kernel_args* args)
 
 	// create the object cache for the page mappings
 	gPageMappingsObjectCache = create_object_cache_etc("page mappings",
-		sizeof(vm_page_mapping), 0, 0, CACHE_LARGE_SLAB, NULL, NULL, NULL,
-		NULL);
+		sizeof(vm_page_mapping), 0, 0, 64, 128, CACHE_LARGE_SLAB, NULL, NULL,
+		NULL, NULL);
 	if (gPageMappingsObjectCache == NULL)
 		panic("failed to create page mappings object cache");