Added more checks regarding page movement for debugging purposes.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20468 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/vm/vm.cpp

@@ -3511,6 +3511,7 @@ vm_soft_fault(addr_t originalAddress, bool isWrite, bool isUser)
 
 	vm_translation_map *map = &addressSpace->translation_map;
 	vm_page dummyPage;
+	dummyPage.cache = NULL;
 	dummyPage.state = PAGE_STATE_INACTIVE;
 	dummyPage.type = PAGE_TYPE_DUMMY;
 

src/system/kernel/vm/vm_cache.c

@@ -269,6 +269,9 @@ vm_cache_lookup_page(vm_cache_ref *cacheRef, off_t offset)
 	release_spinlock(&sPageCacheTableLock);
 	restore_interrupts(state);
 
+	if (page != NULL && cacheRef->cache != page->cache)
+		panic("page %p not in cache %p\n", page, cacheRef->cache);
+
 	return page;
 }
 
@@ -278,9 +281,15 @@ vm_cache_insert_page(vm_cache_ref *cacheRef, vm_page *page, off_t offset)
 {
 	cpu_status state;
 
-	TRACE(("vm_cache_insert_page: cacheRef %p, page %p, offset %Ld\n", cacheRef, page, offset));
+	TRACE(("vm_cache_insert_page: cacheRef %p, page %p, offset %Ld\n",
+		cacheRef, page, offset));
 	ASSERT_LOCKED_MUTEX(&cacheRef->lock);
 
+	if (page->cache != NULL) {
+		panic("insert page %p into cache %p: page cache is set to %p\n",
+			page, cacheRef->cache, page->cache);
+	}
+
 	page->cache_offset = (uint32)(offset >> PAGE_SHIFT);
 
 	if (cacheRef->cache->page_list != NULL)
@@ -300,7 +309,6 @@ vm_cache_insert_page(vm_cache_ref *cacheRef, vm_page *page, off_t offset)
 
 	release_spinlock(&sPageCacheTableLock);
 	restore_interrupts(state);
-
 }
 
 
@@ -317,6 +325,9 @@ vm_cache_remove_page(vm_cache_ref *cacheRef, vm_page *page)
 	TRACE(("vm_cache_remove_page: cache %p, page %p\n", cacheRef, page));
 	ASSERT_LOCKED_MUTEX(&cacheRef->lock);
 
+	if (page->cache != cacheRef->cache)
+		panic("remove page from %p: page cache is set to %p\n", cacheRef->cache, page->cache);
+
 	state = disable_interrupts();
 	acquire_spinlock(&sPageCacheTableLock);
 

src/system/kernel/vm/vm_page.c

@@ -349,6 +349,15 @@ set_page_state_nolock(vm_page *page, int pageState)
 			panic("vm_page_set_state: vm_page %p in invalid state %d\n", page, page->state);
 	}
 
+	if (page->state == PAGE_STATE_CLEAR || page->state == PAGE_STATE_FREE) {
+		if (page->cache != NULL)
+			panic("free page %p has cache", page);
+	}
+	if (pageState == PAGE_STATE_CLEAR || pageState == PAGE_STATE_FREE) {
+		if (page->cache != NULL)
+			panic("to be freed page %p has cache", page);
+	}
+
 	switch (pageState) {
 		case PAGE_STATE_BUSY:
 		case PAGE_STATE_ACTIVE:
@@ -738,6 +747,7 @@ vm_page_init(kernel_args *args)
 		sPages[i].mappings = NULL;
 		sPages[i].wired_count = 0;
 		sPages[i].usage_count = 0;
+		sPages[i].cache = NULL;
 		enqueue_page(&page_free_queue, &sPages[i]);
 	}
 
@@ -942,6 +952,8 @@ vm_page_allocate_page(int page_state)
 			panic("vm_allocate_page: out of memory! page state = %d\n", page_state);
 		}
 	}
+	if (p->cache != NULL)
+		panic("supposed to be free page %p has cache\n", p);
 
 	old_page_state = p->state;
 	p->state = PAGE_STATE_BUSY;