* Some style cleanup.

* Pulled the code moving the pages out of Merge() into a separate method.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34778 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/vm/VMAnonymousCache.cpp

@@ -8,6 +8,7 @@
  * Distributed under the terms of the NewOS License.
  */
 
+
 #include "VMAnonymousCache.h"
 
 #include <errno.h>
@@ -64,6 +65,7 @@
 #define SWAP_BLOCK_SHIFT 5		/* 1 << SWAP_BLOCK_SHIFT == SWAP_BLOCK_PAGES */
 #define SWAP_BLOCK_MASK  (SWAP_BLOCK_PAGES - 1)
 
+
 struct swap_file : DoublyLinkedListLinkImpl<swap_file> {
 	int				fd;
 	struct vnode*	vnode;
@@ -97,7 +99,7 @@ struct SwapHashTableDefinition {
 	{
 		off_t blockIndex = key.page_index >> SWAP_BLOCK_SHIFT;
 		VMAnonymousCache* cache = key.cache;
-		return blockIndex ^ (int)(int *)cache;
+		return blockIndex ^ (size_t)(int*)cache;
 	}
 
 	size_t Hash(const swap_block* value) const
@@ -683,6 +685,13 @@ VMAnonymousCache::CanWritePage(off_t offset)
 }
 
 
+int32
+VMAnonymousCache::MaxPagesPerAsyncWrite() const
+{
+	return 1;
+}
+
+
 status_t
 VMAnonymousCache::Fault(struct VMAddressSpace* aspace, off_t offset)
 {
@@ -744,38 +753,7 @@ VMAnonymousCache::Merge(VMCache* _source)
 
 	// Move all not shadowed pages from the source to the consumer cache.
 
-	for (VMCachePagesTree::Iterator it = source->pages.GetIterator();
+	_MergePagesSmallerSource(source);
-			vm_page* page = it.Next();) {
-		// Note: Removing the current node while iterating through a
-		// IteratableSplayTree is safe.
-		vm_page* consumerPage = LookupPage(
-			(off_t)page->cache_offset << PAGE_SHIFT);
-		swap_addr_t consumerSwapSlot = _SwapBlockGetAddress(page->cache_offset);
-		if (consumerPage == NULL && consumerSwapSlot == SWAP_SLOT_NONE) {
-			// the page is not yet in the consumer cache - move it upwards
-			source->RemovePage(page);
-			InsertPage(page, (off_t)page->cache_offset << PAGE_SHIFT);
-
-			// If the moved-up page has a swap page associated, we mark it, so
-			// that the swap page is moved upwards, too. We would lose if the
-			// page was modified and written to swap, and is now not marked
-			// modified.
-			if (source->_SwapBlockGetAddress(page->cache_offset)
-					!= SWAP_SLOT_NONE) {
-				page->merge_swap = true;
-			}
-#if DEBUG_PAGE_CACHE_TRANSITIONS
-		} else {
-			page->debug_flags = 0;
-			if (consumerPage->state == PAGE_STATE_BUSY)
-				page->debug_flags |= 0x1;
-			if (consumerPage->type == PAGE_TYPE_DUMMY)
-				page->debug_flags |= 0x2;
-			page->collided_page = consumerPage;
-			consumerPage->collided_page = page;
-#endif	// DEBUG_PAGE_CACHE_TRANSITIONS
-		}
-	}
 
 	// Move all not shadowed swap pages from the source to the consumer cache.
 
@@ -844,7 +822,7 @@ VMAnonymousCache::Merge(VMCache* _source)
 		}
 
 		// All source swap pages that have not been freed yet are taken over by
-		// by the consumer.
+		// the consumer.
 		fAllocatedSwapSize += B_PAGE_SIZE * (off_t)sourceSwapBlock->used;
 
 		if (sourceSwapBlock->used == 0) {
@@ -1028,6 +1006,44 @@ VMAnonymousCache::_Commit(off_t size)
 }
 
 
+void
+VMAnonymousCache::_MergePagesSmallerSource(VMAnonymousCache* source)
+{
+	for (VMCachePagesTree::Iterator it = source->pages.GetIterator();
+			vm_page* page = it.Next();) {
+		// Note: Removing the current node while iterating through a
+		// IteratableSplayTree is safe.
+		vm_page* consumerPage = LookupPage(
+			(off_t)page->cache_offset << PAGE_SHIFT);
+		swap_addr_t consumerSwapSlot = _SwapBlockGetAddress(page->cache_offset);
+		if (consumerPage == NULL && consumerSwapSlot == SWAP_SLOT_NONE) {
+			// the page is not yet in the consumer cache - move it upwards
+			source->RemovePage(page);
+			InsertPage(page, (off_t)page->cache_offset << PAGE_SHIFT);
+
+			// If the moved-up page has a swap page associated, we mark it, so
+			// that the swap page is moved upwards, too. We would lose if the
+			// page was modified and written to swap, and is now not marked
+			// modified.
+			if (source->_SwapBlockGetAddress(page->cache_offset)
+					!= SWAP_SLOT_NONE) {
+				page->merge_swap = true;
+			}
+#if DEBUG_PAGE_CACHE_TRANSITIONS
+		} else {
+			page->debug_flags = 0;
+			if (consumerPage->state == PAGE_STATE_BUSY)
+				page->debug_flags |= 0x1;
+			if (consumerPage->type == PAGE_TYPE_DUMMY)
+				page->debug_flags |= 0x2;
+			page->collided_page = consumerPage;
+			consumerPage->collided_page = page;
+#endif	// DEBUG_PAGE_CACHE_TRANSITIONS
+		}
+	}
+}
+
+
 // #pragma mark -
 
 

src/system/kernel/vm/VMAnonymousCache.h

@@ -33,25 +33,28 @@ class VMAnonymousCache : public VMCache {
 public:
 	virtual						~VMAnonymousCache();
 
-			status_t	Init(bool canOvercommit, int32 numPrecommittedPages,
+			status_t			Init(bool canOvercommit,
+									int32 numPrecommittedPages,
 									int32 numGuardPages);
 
 	virtual	status_t			Commit(off_t size);
 	virtual	bool				HasPage(off_t offset);
 
-	virtual	status_t	Read(off_t offset, const iovec *vecs, size_t count,
+	virtual	status_t			Read(off_t offset, const iovec* vecs,
-							uint32 flags, size_t *_numBytes);
+									size_t count, uint32 flags,
-	virtual	status_t	Write(off_t offset, const iovec *vecs, size_t count,
+									size_t* _numBytes);
-							uint32 flags, size_t *_numBytes);
+	virtual	status_t			Write(off_t offset, const iovec* vecs,
+									size_t count, uint32 flags,
+									size_t* _numBytes);
 	virtual	status_t			WriteAsync(off_t offset, const iovec* vecs,
 									size_t count, size_t numBytes, uint32 flags,
 									AsyncIOCallback* callback);
 	virtual	bool				CanWritePage(off_t offset);
 
-	virtual	int32		MaxPagesPerAsyncWrite() const
+	virtual	int32				MaxPagesPerAsyncWrite() const;
-							{ return 1; }
 
-	virtual	status_t	Fault(struct VMAddressSpace* aspace, off_t offset);
+	virtual	status_t			Fault(struct VMAddressSpace* aspace,
+									off_t offset);
 
 	virtual	void				Merge(VMCache* source);
 
@@ -65,6 +68,11 @@ private:
 			swap_addr_t			_SwapBlockGetAddress(off_t pageIndex);
 			status_t			_Commit(off_t size);
 
+			void				_MergePagesSmallerSource(
+									VMAnonymousCache* source);
+			void				_MergePagesSmallerConsumer(
+									VMAnonymousCache* source);
+
 private:
 	friend bool swap_free_page_swap_space(vm_page* page);
 
@@ -78,6 +86,8 @@ private:
 
 #endif	// ENABLE_SWAP_SUPPORT
 
+
 extern "C" void swap_get_info(struct system_memory_info* info);
 
+
 #endif	/* _KERNEL_VM_STORE_ANONYMOUS_H */