]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/vm/task_working_set.c
xnu-344.23.tar.gz
[apple/xnu.git] / osfmk / vm / task_working_set.c
index fa3f8f1d27f8e96ed02b112ad3aa65584759d687..90859e626204b8ab7148676931cf26220da475ec 100644 (file)
@@ -1,5 +1,6 @@
+int    startup_miss = 0;
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2002,2000 Apple Computer, Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
  */
 
 
-#include <mach/rpc.h>
+#include <mach/mach_types.h>
+#include <mach/shared_memory_server.h>
 #include <vm/task_working_set.h>
+#include <vm/vm_kern.h>
 #include <vm/vm_map.h>
 #include <vm/vm_page.h>
 #include <vm/vm_pageout.h>
 #include <kern/sched.h>
 
 extern unsigned sched_tick;
+extern zone_t lsf_zone;
+
+/* declarations for internal use only routines */
+
+tws_startup_t
+tws_create_startup_list(
+       tws_hash_t      tws);
+
+unsigned int
+tws_startup_list_lookup(
+        tws_startup_t   startup,
+        vm_offset_t     addr);
+
+kern_return_t
+tws_internal_startup_send(
+       tws_hash_t      tws);
+
+void
+tws_traverse_address_hash_list (
+       tws_hash_t              tws, 
+       unsigned int            index,
+       vm_offset_t             page_addr,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       vm_map_t                map,
+       tws_hash_ptr_t          *target_ele,
+       tws_hash_ptr_t          **previous_ptr,
+       tws_hash_ptr_t          **free_list,
+       unsigned int            exclusive_addr);
+
+void
+tws_traverse_object_hash_list (
+       tws_hash_t              tws, 
+       unsigned int            index,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       unsigned int            page_mask,
+       tws_hash_ptr_t          *target_ele,
+       tws_hash_ptr_t          **previous_ptr,
+       tws_hash_ptr_t          **free_list);
+
+tws_hash_ptr_t
+new_addr_hash(
+       tws_hash_t tws, 
+       unsigned int set, 
+       unsigned int index);
+
+tws_hash_ptr_t
+new_obj_hash(
+       tws_hash_t tws, 
+       unsigned int set, 
+       unsigned int index);
+
+int tws_test_for_community(
+               tws_hash_t              tws, 
+               vm_object_t             object, 
+               vm_object_offset_t      offset, 
+               unsigned int            threshold, 
+               unsigned int            *page_mask);
 
 /* Note:  all of the routines below depend on the associated map lock for */
 /* synchronization, the map lock will be on when the routines are called  */
@@ -63,36 +125,55 @@ tws_hash_create(
        if(tws == (tws_hash_t)NULL)
                return tws;
 
-       if((tws->table[0] = (tws_hash_ele_t *)
-                       kalloc(sizeof(tws_hash_ele_t) * 2 * lines * rows)) 
+       if((tws->table[0] = (tws_hash_ptr_t *)
+                       kalloc(sizeof(tws_hash_ptr_t) * lines * rows)) 
                                                                == NULL) {
                kfree((vm_offset_t)tws, sizeof(struct tws_hash));
                return (tws_hash_t)NULL;
        }
-       if((tws->alt_table[0] = (tws_hash_ele_t *)
-                       kalloc(sizeof(tws_hash_ele_t) * 2 * lines * rows))
+       if((tws->table_ele[0] = (tws_hash_ptr_t)
+                       kalloc(sizeof(struct tws_hash_ptr) * lines * rows)) 
                                                                == NULL) {
-               kfree((vm_offset_t)tws, sizeof(struct tws_hash));
                kfree((vm_offset_t)tws->table[0], sizeof(tws_hash_ele_t) 
-                               * 2 * lines * rows);
+                               * lines * rows);
+               kfree((vm_offset_t)tws, sizeof(struct tws_hash));
+               return (tws_hash_t)NULL;
+       }
+       if((tws->alt_ele[0] = (tws_hash_ptr_t)
+                       kalloc(sizeof(struct tws_hash_ptr) * lines * rows))
+                                                               == NULL) {
+               kfree((vm_offset_t)tws->table[0], sizeof(tws_hash_ptr_t) 
+                               * lines * rows);
+               kfree((vm_offset_t)tws->table_ele[0],
+                               sizeof(struct tws_hash_ptr) 
+                               * lines * rows);
+               kfree((vm_offset_t)tws, sizeof(struct tws_hash));
                return (tws_hash_t)NULL;
        }
        if((tws->cache[0] = (struct tws_hash_line *)
                        kalloc(sizeof(struct tws_hash_line) * lines))
                                                                == NULL) {
+               kfree((vm_offset_t)tws->table[0], sizeof(tws_hash_ptr_t) 
+                               * lines * rows);
+               kfree((vm_offset_t)tws->table_ele[0],
+                               sizeof(struct tws_hash_ptr)
+                               * lines * rows);
+               kfree((vm_offset_t)tws->alt_ele[0], sizeof(struct tws_hash_ptr) 
+                               * lines * rows);
                kfree((vm_offset_t)tws, sizeof(struct tws_hash));
-               kfree((vm_offset_t)tws->table[0], sizeof(tws_hash_ele_t) 
-                               * 2 * lines * rows);
-               kfree((vm_offset_t)tws->alt_table[0], sizeof(tws_hash_ele_t) 
-                               * 2 * lines * rows);
                return (tws_hash_t)NULL;
        }
+       tws->free_hash_ele[0] = (tws_hash_ptr_t)0;
+       tws->obj_free_count[0] = 0;
+       tws->addr_free_count[0] = 0;
 
        /* most defaults are such that a bzero will initialize */
-       bzero((char *)tws->table[0],sizeof(tws_hash_ele_t)
-                                       * 2 * lines * rows);
-       bzero((char *)tws->alt_table[0],sizeof(tws_hash_ele_t)
-                                       * 2 * lines * rows);
+       bzero((char *)tws->table[0],sizeof(tws_hash_ptr_t)
+                                       * lines * rows);
+       bzero((char *)tws->table_ele[0],sizeof(struct tws_hash_ptr)
+                                       * lines * rows);
+       bzero((char *)tws->alt_ele[0],sizeof(struct tws_hash_ptr)
+                                       * lines * rows);
        bzero((char *)tws->cache[0], sizeof(struct tws_hash_line) 
                                        * lines);
 
@@ -101,6 +182,8 @@ tws_hash_create(
        tws->current_line = 0;
        tws->pageout_count = 0;
        tws->line_count = 0;
+       tws->startup_cache = NULL;
+       tws->startup_name = NULL;
        tws->number_of_lines = lines;
        tws->number_of_elements = rows;
        tws->expansion_count = 1;
@@ -119,9 +202,11 @@ tws_hash_line_clear(
        boolean_t live)
 {
        struct tws_hash_ele     *hash_ele;
+       struct tws_hash_ptr     **trailer;
+       struct tws_hash_ptr     **free_list;
+       tws_hash_ele_t          addr_ele;
        int                     index;
        unsigned int            i, j, k;
-       int                     alt_index;
        int                     dump_pmap;
        int                     hash_loop;
 
@@ -140,83 +225,99 @@ tws_hash_line_clear(
                }
        }
        hash_line->ele_count = 0;
-       for (i=0; i<tws->number_of_elements; i++) {
-          hash_loop = 0;
-          hash_ele = &(hash_line->list[i]);
-          if(hash_ele->object != 0) {
-               vm_offset_t     vaddr_off = 0;
-               vm_object_offset_t local_off = 0;
 
-               for (j = 0x1; j != 0; j = j<<1) {
-                       if(j & hash_ele->page_cache) {
-                               unsigned int    alt_index;
-                               alt_index = alt_tws_hash(
-                                       hash_ele->page_addr + vaddr_off,
-                                       tws->number_of_elements, 
-                                       tws->number_of_lines);
-                               for(k = 0; k < tws->expansion_count; k++) {
-                                if(tws->alt_table[k][alt_index] == hash_ele) {
-                                       tws->alt_table[k][alt_index] = 0;
-                                }
-                               }
-                               vaddr_off += PAGE_SIZE;
-                       }
-               }
-
-               if((hash_ele->map != NULL) && (live)) {
-                       vm_page_t       p;
-
-                       for (j = 0x1; j != 0; j = j<<1) {
-                          if(j & hash_ele->page_cache) {
-                               p = vm_page_lookup(hash_ele->object, 
+       for (i=0; i<tws->number_of_elements; i++) {
+               hash_loop = 0;
+               hash_ele = &(hash_line->list[i]);
+               if(hash_ele->object != 0) {
+       
+                       vm_object_offset_t local_off = 0;
+                       tws_hash_ptr_t  cache_ele;
+       
+                       index = alt_tws_hash(
+                               hash_ele->page_addr & TWS_HASH_OFF_MASK,
+                               tws->number_of_elements, 
+                               tws->number_of_lines);
+       
+                       tws_traverse_address_hash_list(tws, index, 
+                               hash_ele->page_addr, hash_ele->object,
+                               hash_ele->offset, hash_ele->map,
+                               &cache_ele, &trailer, &free_list, 0);
+                       if(cache_ele != NULL) {
+                               addr_ele = (tws_hash_ele_t)((unsigned int)
+                                  (cache_ele->element) & ~TWS_ADDR_HASH);
+                               if(addr_ele != hash_ele)
+                                       panic("tws_hash_line_clear:"
+                                               " out of sync\n");
+                               cache_ele->element = 0;
+                               *trailer = cache_ele->next;
+                               cache_ele->next = *free_list;
+                               *free_list = cache_ele;
+                       }
+       
+                       index = alt_tws_hash(
+                               (hash_ele->page_addr - 0x1f000) 
+                                               & TWS_HASH_OFF_MASK,
+                               tws->number_of_elements, 
+                               tws->number_of_lines);
+
+                       tws_traverse_address_hash_list(tws, index, 
+                               hash_ele->page_addr, hash_ele->object, 
+                               hash_ele->offset, hash_ele->map,
+                               &cache_ele, &trailer, &free_list, 0);
+
+                       if(cache_ele != NULL) {
+                               addr_ele = (tws_hash_ele_t)((unsigned int)
+                                  (cache_ele->element) & ~TWS_ADDR_HASH);
+                               if(addr_ele != hash_ele)
+                                       panic("tws_hash_line_clear: "
+                                               "out of sync\n");
+                               cache_ele->element = 0;
+                               *trailer = cache_ele->next;
+                               cache_ele->next = *free_list;
+                               *free_list = cache_ele;
+                       }
+       
+       
+                       if((hash_ele->map != NULL) && (live)) {
+                               vm_page_t       p;
+       
+                               for (j = 0x1; j != 0; j = j<<1) {
+                                  if(j & hash_ele->page_cache) {
+                                       p = vm_page_lookup(hash_ele->object, 
                                                hash_ele->offset + local_off);
-                               if((p != NULL) && (p->wire_count == 0) 
-                                               && (dump_pmap == 1)) {
-                                       pmap_remove_some_phys((pmap_t)
-                                               vm_map_pmap(hash_ele->map),
-                                               p->phys_addr);
+                                       if((p != NULL) && (p->wire_count == 0) 
+                                                       && (dump_pmap == 1)) {
+                                               pmap_remove_some_phys((pmap_t)
+                                                       vm_map_pmap(
+                                                               hash_ele->map),
+                                                       p->phys_addr);
+                                       }
+                                  }
+                                  local_off += PAGE_SIZE_64;
                                }
-                          }
-                          local_off += PAGE_SIZE_64;
                        }
-               }
-               if(tws->style == TWS_HASH_STYLE_SIGNAL) {
-                       vm_object_deallocate(hash_ele->object);
-                       vm_map_deallocate(hash_ele->map);
-               }
+       
+                       if(tws->style == TWS_HASH_STYLE_SIGNAL) {
+                               vm_object_deallocate(hash_ele->object);
+                               vm_map_deallocate(hash_ele->map);
+                       }
 
-               index = do_tws_hash(hash_ele->object, hash_ele->offset,
-                               tws->number_of_elements, tws->number_of_lines);
+                       index = do_tws_hash(hash_ele->object, hash_ele->offset,
+                                       tws->number_of_elements, 
+                                       tws->number_of_lines);
 
-               while (hash_loop < TWS_MAX_REHASH) {
-                       for(k = 0; k < tws->expansion_count; k++) {
-                               if((tws->table[k][index] != 0) && 
-                                       (tws->table[k][index] == hash_ele)) {
-                                       tws->table[k][index] = 0;
-                                       break;
-                               }
-                               if(k < tws->expansion_count)
-                                       break;
+                       tws_traverse_object_hash_list(tws,
+                               index, hash_ele->object, hash_ele->offset,
+                               0xFFFFFFFF, &cache_ele, &trailer, &free_list);
+                       if((cache_ele != NULL) && (cache_ele->element == hash_ele)) {
+                               cache_ele->element = 0;
+                               *trailer = cache_ele->next;
+                               cache_ele->next = *free_list;
+                               *free_list = cache_ele;
                        }
-                       index += 17;
-                       if(index >= (2 * 
-                               tws->number_of_lines 
-                                       * tws->number_of_elements)) {
-                               index = index - (2 * 
-                                       tws->number_of_lines 
-                                       * tws->number_of_elements);
-                       }
-                       hash_loop++;
+                       hash_ele->object = 0;
                }
-               hash_ele->object = 0;
-               hash_ele->page_cache = 0;
-
-if(newtest != 0) {
-       if (hash_loop == TWS_MAX_REHASH) {
-               panic("tws_hash_line_clear: Cache and Hash out of sync\n");
-       }
-}
-          }
        }
 }
 
@@ -227,10 +328,14 @@ tws_lookup(
        vm_object_t             object,
        tws_hash_line_t          *line) 
 {
-       struct tws_hash_ele     *hash_ele;
        int                     index;
-       int                     k;
        int                     loop;
+       int                     set; 
+       int                     ele_line;
+       vm_offset_t             pagenum;
+       tws_hash_ptr_t          cache_ele;
+       tws_hash_ptr_t          *trailer;
+       tws_hash_ptr_t          *free_list;
 
        /* don't cache private objects */
        if(object->private)
@@ -247,45 +352,54 @@ tws_lookup(
        tws->lookup_count++; 
        if(tws->lookup_count == 0)
                tws->insert_count = 0;
-       while (loop < TWS_MAX_REHASH) {
-          for(k=0; k<tws->expansion_count; k++) {
-             if((hash_ele = tws->table[k][index]) != 0) {
-               if((hash_ele->offset == (offset & TWS_HASH_OFF_MASK)) 
-                               && (hash_ele->object == object)) {
-                       vm_offset_t     pagenum;
-
-                       pagenum = (vm_offset_t)
-                               (offset & TWS_INDEX_MASK);
-                       pagenum = pagenum >> 12;
-                       
-                       if((1<<pagenum) & hash_ele->page_cache) {
-                               int             set; 
-                               int             ele_line;
+       if(tws->startup_name != NULL) {
+               int age_of_cache;
+               age_of_cache = ((sched_tick 
+                       - tws->time_of_creation) >> SCHED_TICK_SHIFT);
+                       if (age_of_cache > 35) {
+                       tws_unlock(tws); 
+                       return KERN_OPERATION_TIMED_OUT;
+               }
+       }
 
-                               set = hash_ele->line/tws->number_of_lines;
-                               ele_line = hash_ele->line - set;
-                               *line = &tws->cache[k][ele_line];
-                               tws_unlock(tws);
-                               return KERN_SUCCESS;
+       if(tws->lookup_count > (4 * tws->expansion_count 
+                       * tws->number_of_elements * tws->number_of_lines) &&
+                       (tws->lookup_count > (2 * tws->insert_count))) {
+               if(tws->startup_cache) {
+                       int age_of_cache;
+                       age_of_cache = ((sched_tick 
+                               - tws->time_of_creation) >> SCHED_TICK_SHIFT);
+                       if (age_of_cache > 60) {
+                               tws_unlock(tws); 
+                               return KERN_OPERATION_TIMED_OUT;
                        }
-               }
-             }
-          }
-          index += 17;
-          if(index >= (2 * tws->number_of_lines * tws->number_of_elements)) {
-               index = index -
-                       (2 * tws->number_of_lines * tws->number_of_elements);
-          }
-          loop++;
+               }
        }
+
+       pagenum = (vm_offset_t)(offset & TWS_INDEX_MASK);
+       pagenum = pagenum >> 12;
+       pagenum = 1 << pagenum;  /* get the appropriate page in 32 page block */
+       tws_traverse_object_hash_list(tws, index, object, offset, pagenum,
+               &cache_ele, &trailer, &free_list);
+       if(cache_ele != NULL) {
+               set = cache_ele->element->line/tws->number_of_lines;
+               ele_line = cache_ele->element->line - set;
+               *line = &tws->cache[set][ele_line];
+               tws_unlock(tws);
+               return KERN_SUCCESS;
+       }
+
        tws_unlock(tws);
        return KERN_FAILURE;
+
+
 }
 
 kern_return_t
 tws_expand_working_set(
        vm_offset_t     tws, 
-       int             line_count)
+       int             line_count,
+       boolean_t       dump_data)
 {
        tws_hash_t              new_tws;
        tws_hash_t              old_tws;
@@ -307,14 +421,15 @@ tws_expand_working_set(
        }
        tws_lock(old_tws);
        
-       for(i = 0; i<old_tws->number_of_lines; i++) {
-          for(j = 0; j<old_tws->number_of_elements; j++) {
-             for(k = 0; k<old_tws->expansion_count; k++) {
-               tws_hash_ele_t          entry;
-               vm_object_offset_t      paddr;
-               unsigned int            page_index;
-               entry = &old_tws->cache[k][i].list[j];
-               if(entry->object != 0) {
+       if(!dump_data) {
+          for(i = 0; i<old_tws->number_of_lines; i++) {
+             for(j = 0; j<old_tws->number_of_elements; j++) {
+                for(k = 0; k<old_tws->expansion_count; k++) {
+                   tws_hash_ele_t              entry;
+                   vm_object_offset_t  paddr;
+                   unsigned int                page_index;
+                   entry = &old_tws->cache[k][i].list[j];
+                   if(entry->object != 0) {
                        paddr = 0;
                        for(page_index = 1; page_index != 0; 
                                        page_index = page_index << 1); {
@@ -328,8 +443,9 @@ tws_expand_working_set(
                                paddr+=PAGE_SIZE;
                        }
                
-               }
-            }
+                   }
+               }
+             }
           }
        }
 
@@ -343,8 +459,12 @@ tws_expand_working_set(
        temp.lookup_count = new_tws->lookup_count;
        temp.insert_count = new_tws->insert_count;
        for(i = 0; i<new_tws->expansion_count; i++) {
+               temp.obj_free_count[i] = new_tws->obj_free_count[i];
+               temp.addr_free_count[i] = new_tws->addr_free_count[i];
+               temp.free_hash_ele[i] = new_tws->free_hash_ele[i];
                temp.table[i] = new_tws->table[i];
-               temp.alt_table[i] = new_tws->alt_table[i];
+               temp.table_ele[i] = new_tws->table_ele[i];
+               temp.alt_ele[i] = new_tws->alt_ele[i];
                temp.cache[i] = new_tws->cache[i];
        }
 
@@ -358,8 +478,12 @@ tws_expand_working_set(
        new_tws->lookup_count = old_tws->lookup_count;
        new_tws->insert_count = old_tws->insert_count;
        for(i = 0; i<old_tws->expansion_count; i++) {
+               new_tws->obj_free_count[i] = old_tws->obj_free_count[i];
+               new_tws->addr_free_count[i] = old_tws->addr_free_count[i];
+               new_tws->free_hash_ele[i] = old_tws->free_hash_ele[i];
                new_tws->table[i] = old_tws->table[i];
-               new_tws->alt_table[i] = old_tws->alt_table[i];
+               new_tws->table_ele[i] = old_tws->table_ele[i];
+               new_tws->alt_ele[i] = old_tws->alt_ele[i];
                new_tws->cache[i] = old_tws->cache[i];
        }
        
@@ -373,8 +497,12 @@ tws_expand_working_set(
        old_tws->lookup_count = temp.lookup_count;
        old_tws->insert_count = temp.insert_count;
        for(i = 0; i<temp.expansion_count; i++) {
+               old_tws->obj_free_count[i] = temp.obj_free_count[i];;
+               old_tws->addr_free_count[i] = temp.addr_free_count[i];;
+               old_tws->free_hash_ele[i] = NULL;
                old_tws->table[i] = temp.table[i];
-               old_tws->alt_table[i] = temp.alt_table[i];
+               old_tws->table_ele[i] = temp.table_ele[i];
+               old_tws->alt_ele[i] = temp.alt_ele[i];
                old_tws->cache[i] = temp.cache[i];
        }
 
@@ -383,6 +511,8 @@ tws_expand_working_set(
        return  KERN_SUCCESS;
 }
 
+tws_hash_t     test_tws = 0;
+
 kern_return_t
 tws_insert(
        tws_hash_t              tws, 
@@ -392,17 +522,25 @@ tws_insert(
        vm_map_t                map)
 {
        queue_t                 bucket;
-       struct tws_hash_ele     *new_entry;
        unsigned int            index;
        unsigned int            alt_index;
+       unsigned int            index_enum[2];
        unsigned int            ele_index;
-       unsigned int            page_index;
+       tws_hash_ptr_t          cache_ele;
+       tws_hash_ptr_t          obj_ele = NULL;
+       tws_hash_ptr_t          addr_ele = NULL;
+       tws_hash_ptr_t          *trailer;
+       tws_hash_ptr_t          *free_list;
+       tws_hash_ele_t          target_element = NULL;
        int                     i,k;
-       int                     alt_k;
-       int                     alt_hash_count;
        int                     current_line;
        int                     set;
-       int                     hash_loop;
+       int                     ctr;
+       unsigned int            startup_cache_line;
+       vm_offset_t             startup_page_addr;
+       int                     cache_full = 0;
+       int                     ask_for_startup_cache_release = 0;
+
 
        if(!tws_lock_try(tws)) {
                return KERN_FAILURE;
@@ -410,133 +548,177 @@ tws_insert(
        tws->insert_count++;
        current_line = 0xFFFFFFFF;
 
+       startup_cache_line = 0;
+       startup_page_addr =
+                        page_addr - (offset - (offset & TWS_HASH_OFF_MASK));
+       if(tws->startup_cache) {
+             int age_of_cache;
+             age_of_cache = ((sched_tick - tws->time_of_creation) 
+                                               >> SCHED_TICK_SHIFT);
+               startup_cache_line = tws_startup_list_lookup(
+                                       tws->startup_cache, startup_page_addr);
+if(tws == test_tws) {
+printf("cache_lookup, result = 0x%x, addr = 0x%x, object 0x%x, offset 0x%x%x\n", startup_cache_line, startup_page_addr, object, offset);
+}
+               if(age_of_cache > 60) {
+                       ask_for_startup_cache_release = 1;
+               }
+       }
+       if((tws->startup_name != NULL) && (tws->mod == 0)) {
+                       /* Ensure as good a working set as possible */
+                       pmap_remove(map->pmap, 0, GLOBAL_SHARED_TEXT_SEGMENT);
+                       pmap_remove(map->pmap, 
+                               GLOBAL_SHARED_DATA_SEGMENT 
+                               + SHARED_DATA_REGION_SIZE, 0xFFFFF000);
+       }
+
        /* This next bit of code, the and alternate hash */
        /* are all made necessary because of IPC COW     */
 
-       alt_index = alt_tws_hash(page_addr,
+       /* Note: the use of page_addr modified by delta from offset */
+       /* frame base means we may miss some previous entries.  However */
+       /* we will not miss the present entry.  This is most important */
+       /* in avoiding duplication of entries against long lived non-cow */
+       /* objects */
+       index_enum[0] = alt_tws_hash(
+                       page_addr & TWS_HASH_OFF_MASK,
                        tws->number_of_elements, tws->number_of_lines);
 
-       for(alt_k=0; alt_k<tws->expansion_count; alt_k++) {
-               new_entry = tws->alt_table[alt_k][alt_index];
-               if((new_entry == 0) || (new_entry->object == 0)) {
-                       tws->alt_table[alt_k][alt_index] = 0;
-                       continue;
-               }
-               if(!((new_entry->offset == (offset & TWS_HASH_OFF_MASK)) 
-                       && (new_entry->object == object))) {
-
-                       tws->alt_table[alt_k][alt_index] = 0;
-
-                       index = do_tws_hash(
-                               new_entry->object, new_entry->offset,
-                               tws->number_of_elements, tws->number_of_lines);
-
-                       hash_loop = 0;
-                       while (hash_loop < TWS_MAX_REHASH) {
-
-                          for(k=0; k<tws->expansion_count; k++) {
-                               if(tws->table[k][index] == new_entry) {
-                                       break;
-                               }
-                          }
+       index_enum[1] = alt_tws_hash(
+                       (page_addr - 0x1f000) & TWS_HASH_OFF_MASK,
+                       tws->number_of_elements, tws->number_of_lines);
 
-                          if(k == tws->expansion_count) {
-                               index+=17;
-                               if(index >= (2 * tws->number_of_lines 
-                                               * tws->number_of_elements)) {
-                                       index = index - 
-                                               (2 * tws->number_of_lines 
-                                               * tws->number_of_elements);
-                               }
-                          } else {
+       for(ctr = 0; ctr < 2;) {
+               tws_hash_ele_t  resident;
+               tws_traverse_address_hash_list(tws, 
+                               index_enum[ctr], page_addr, NULL,
+                               0, NULL,
+                               &cache_ele, &trailer, &free_list, 1);
+               if(cache_ele != NULL) {
+                       /* found one */
+                       resident = (tws_hash_ele_t)((unsigned int)
+                                       cache_ele->element & ~TWS_ADDR_HASH);
+                       if((object == resident->object) &&
+                               resident->offset == 
+                                       (offset & TWS_HASH_OFF_MASK)) {
+                               /* This is our object/offset */
+                               resident->page_cache 
+                                               |= startup_cache_line;
+                               resident->page_cache |= 
+                                  (1<<(((vm_offset_t)
+                                  (offset & TWS_INDEX_MASK))>>12));
+                               tws_unlock(tws);
+                               if(ask_for_startup_cache_release)
+                                       return KERN_OPERATION_TIMED_OUT;
+                               return KERN_SUCCESS;
+                       }
+                       if((object->shadow ==
+                               resident->object) && 
+                               ((resident->offset 
+                               + object->shadow_offset) 
+                               == (offset & TWS_HASH_OFF_MASK))) {
+                               /* if we just shadowed, inherit */
+                               /* access pattern from  parent */
+                               startup_cache_line |= 
+                                  resident->page_cache;
+                               /* thow out old entry */
+                               resident->page_cache = 0;
                                break;
-                          }
-                          hash_loop++;
-
+                       } else {
+                               resident->page_cache &= 
+                                  ~(1<<(((vm_offset_t)(page_addr 
+                                       - resident->page_addr))
+                                       >>12));
                        }
-                       if((k < tws->expansion_count) && 
-                                       (tws->table[k][index] == new_entry)) {
-                               page_index = (offset & TWS_INDEX_MASK) >> 12;
-                               new_entry->page_cache &= 
-                                       ~((unsigned int)(1 << page_index));
-
-                               if(new_entry->page_cache == 0) {
-
+                       /* Throw out old entry if there are no */
+                       /* more pages in cache */
+                       if(resident->page_cache == 0) {
+                               /* delete addr hash entry */
+                               cache_ele->element = 0;
+                               *trailer = cache_ele->next;
+                               cache_ele->next = *free_list;
+                               *free_list = cache_ele;
+                               /* go after object hash */
+                               index = do_tws_hash(
+                                       resident->object, 
+                                       resident->offset,
+                                       tws->number_of_elements, 
+                                       tws->number_of_lines);
+                               tws_traverse_object_hash_list(tws,
+                                       index, resident->object, 
+                                       resident->offset,
+                                       0xFFFFFFFF, &cache_ele,
+                                       &trailer, &free_list);
+                               if(cache_ele != NULL) {
                                        if(tws->style == 
-                                               TWS_HASH_STYLE_SIGNAL) {
+                                          TWS_HASH_STYLE_SIGNAL) {
                                                vm_object_deallocate(
-                                                       new_entry->object);
+                                                  cache_ele->element->object);
                                                vm_map_deallocate(
-                                                       new_entry->map);
+                                                  cache_ele->element->map);
+                                       }
+                                       current_line = 
+                                          cache_ele->element->line;
+                                       set = current_line
+                                               /tws->number_of_lines;
+                                       current_line -= set *
+                                               tws->number_of_lines;
+                                       if(cache_ele->element->object != 0) {
+                                               cache_ele->element->object = 0;
+                                               tws->cache[set]
+                                                       [current_line].ele_count--;
                                        }
-                                       new_entry->object = 0;
-                                       tws->table[k][index] = 0;
-                                       current_line = new_entry->line;
-                                       set = current_line/tws->number_of_lines;
-                                       current_line = current_line - 
-                                               (set * tws->number_of_lines);
-                                       tws->cache[set]
-                                               [current_line].ele_count--;
+                                       cache_ele->element = 0;
+                                       *trailer = cache_ele->next;
+                                       cache_ele->next = *free_list;
+                                       *free_list = cache_ele;
                                }
-
                        }
-                       break;
+                       continue;
                }
+               ctr+=1;
        }
 
+       /* 
+        * We may or may not have a current line setting coming out of
+        * the code above.  If we have a current line it means we can
+        * choose to back-fill the spot vacated by a previous entry.
+        * We have yet to do a definitive check using the original obj/off
+        * We will do that now and override the current line if we
+        * find an element
+        */
+
        index = do_tws_hash(object, offset, 
                        tws->number_of_elements, tws->number_of_lines);
-       alt_hash_count = 0;
-       /* we will do MAX_REHASH hash attempts and then give up */
-       while (alt_hash_count < TWS_MAX_REHASH) {
-               for(k=0; k<tws->expansion_count; k++) {
-                       new_entry = tws->table[k][index];
-                       if(new_entry == NULL)
-                               continue;
-                       if((new_entry->object == object) && 
-                               (new_entry->offset == 
-                               (offset & TWS_HASH_OFF_MASK))) {
-                               new_entry->page_cache |= 
-                               (1<<(((vm_offset_t)
-                               (offset & TWS_INDEX_MASK))>>12));
-                               tws->alt_table[k][alt_index] =  new_entry;
-                               tws_unlock(tws);
-                               return KERN_SUCCESS;
-                       }
-               }
-
-               alt_hash_count += 1;
-               index += 17;
-               if(index >= (2 * 
-                       tws->number_of_lines * tws->number_of_elements))
-                       index = index - 
-                       (2 * tws->number_of_lines * tws->number_of_elements);
-       }
-       alt_hash_count = 0;
-       index = do_tws_hash(object, offset,
-                       tws->number_of_elements, tws->number_of_lines);
-       while (alt_hash_count < TWS_MAX_REHASH) {
-               for(k=0; k<tws->expansion_count; k++) {
-                       new_entry = tws->table[k][index];
-                       if(new_entry == NULL)
-                               break;
-               }
 
-               if (k<tws->expansion_count)
-                       break;
+       alt_index = index_enum[0];
 
-               alt_hash_count += 1;
-               index += 17;
-               if(index >= (2 * 
-                       tws->number_of_lines * tws->number_of_elements))
-                       index = index - 
-                       (2 * tws->number_of_lines * tws->number_of_elements);
+       tws_traverse_object_hash_list(tws, index, object, offset,
+                       0xFFFFFFFF, &cache_ele, &trailer, &free_list);
+       if(cache_ele != NULL) {
+               obj_ele = cache_ele;
+               current_line = cache_ele->element->line;
+               set = current_line/tws->number_of_lines;
+               current_line -= set * tws->number_of_lines;
+               target_element = cache_ele->element;
+
+               /* Now check to see if we have a hash addr for it */
+               tws_traverse_address_hash_list(tws, 
+                               alt_index, obj_ele->element->page_addr,
+                               obj_ele->element->object,
+                               obj_ele->element->offset,
+                               obj_ele->element->map,
+                               &cache_ele, &trailer, &free_list, 0);
+               if(cache_ele != NULL) {
+                       addr_ele = cache_ele;
+               } else  {
+                       addr_ele = new_addr_hash(tws, set, alt_index);
+                       /* if cannot allocate just do without */
+                       /* we'll get it next time around */
+               }
        }
 
-       if(alt_hash_count == TWS_MAX_REHASH) {
-               tws_unlock(tws);
-               return KERN_FAILURE;
-       }
+
 
        if(tws->style == TWS_HASH_STYLE_SIGNAL) {
                vm_object_reference(object);
@@ -544,13 +726,17 @@ tws_insert(
        }
 
        if(current_line == 0xFFFFFFFF) {
-
                current_line = tws->current_line;
                set = current_line/tws->number_of_lines;
                current_line = current_line - (set * tws->number_of_lines);
 
+#ifdef notdef
+               if(cache_full) {
+                       tws->current_line = tws->number_of_lines - 1;
+               }
+#endif
                if(tws->cache[set][current_line].ele_count 
-                                       >= tws->number_of_elements) {
+                               >= tws->number_of_elements) {
                        current_line++;
                        tws->current_line++;
                        if(current_line == tws->number_of_lines) {
@@ -568,21 +754,36 @@ tws_insert(
                                        tws_unlock(tws);
                                        return KERN_NO_SPACE;
                                      }
-                                     if((tws->table[set] = (tws_hash_ele_t *)
-                                        kalloc(sizeof(tws_hash_ele_t) 
-                                               * 2 * tws->number_of_lines 
+                                     if((tws->table[set] = (tws_hash_ptr_t *)
+                                        kalloc(sizeof(tws_hash_ptr_t) 
+                                               * tws->number_of_lines 
                                                * tws->number_of_elements)) 
                                                                == NULL) {
                                         set = 0;
-                                     } else if((tws->alt_table[set] = 
-                                               (tws_hash_ele_t *)
-                                               kalloc(sizeof(tws_hash_ele_t)
-                                               * 2 * tws->number_of_lines 
+                                     } else if((tws->table_ele[set] = 
+                                       (tws_hash_ptr_t)
+                                        kalloc(sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
                                                * tws->number_of_elements)) 
                                                                == NULL) {
                                         kfree((vm_offset_t)tws->table[set], 
-                                               sizeof(tws_hash_ele_t) 
-                                               * 2 * tws->number_of_lines 
+                                               sizeof(tws_hash_ptr_t) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
+                                        set = 0;
+                                     } else if((tws->alt_ele[set] = 
+                                               (tws_hash_ptr_t)
+                                        kalloc(sizeof(struct tws_hash_ptr)
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements)) 
+                                                               == NULL) {
+                                       kfree((vm_offset_t)tws->table_ele[set], 
+                                               sizeof(tws_hash_ptr_t) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
+                                        kfree((vm_offset_t)tws->table[set], 
+                                               sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
                                                * tws->number_of_elements);
                                         tws->table[set] = NULL;
                                         set = 0;
@@ -594,30 +795,67 @@ tws_insert(
                                                * tws->number_of_lines)) 
                                                                == NULL) {
                                         kfree((vm_offset_t)tws->table[set], 
-                                                       sizeof(tws_hash_ele_t) 
-                                                       * 2 * tws->number_of_lines 
-                                                       * tws->number_of_elements);
-                                        kfree((vm_offset_t)tws->alt_table[set], 
-                                                       sizeof(tws_hash_ele_t) 
-                                                       * 2 * tws->number_of_lines 
-                                                       * tws->number_of_elements);
+                                               sizeof(tws_hash_ptr_t) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
+                                       kfree((vm_offset_t)tws->table_ele[set], 
+                                               sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
+                                        kfree((vm_offset_t)tws->alt_ele[set], 
+                                               sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
                                         tws->table[set] = NULL;
                                         set = 0;
                                                        
                                      } else {
+                                        tws->free_hash_ele[set] = 
+                                                       (tws_hash_ptr_t)0;
+                                        tws->obj_free_count[set] = 0;
+                                        tws->addr_free_count[set] = 0;
                                         bzero((char *)tws->table[set], 
-                                               sizeof(tws_hash_ele_t) 
-                                               * 2 * tws->number_of_lines 
+                                               sizeof(tws_hash_ptr_t) 
+                                               * tws->number_of_lines 
                                                * tws->number_of_elements);
-                                        bzero((char *)tws->alt_table[set], 
-                                               sizeof(tws_hash_ele_t) 
-                                               * 2 * tws->number_of_lines 
+                                        bzero((char *)tws->table_ele[set], 
+                                               sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
+                                               * tws->number_of_elements);
+                                        bzero((char *)tws->alt_ele[set], 
+                                               sizeof(struct tws_hash_ptr) 
+                                               * tws->number_of_lines 
                                                * tws->number_of_elements);
                                         bzero((char *)tws->cache[set], 
                                                sizeof(struct tws_hash_line) 
                                                * tws->number_of_lines);
                                      }
                                   } else {
+                                     int age_of_cache;
+                                     age_of_cache = 
+                                               ((sched_tick - 
+                                                   tws->time_of_creation) 
+                                                       >> SCHED_TICK_SHIFT);
+       
+                                     if((tws->startup_cache) && 
+                                                       (age_of_cache > 60)) {
+                                        ask_for_startup_cache_release = 1;
+                                     }
+                                     if((tws->startup_name != NULL) &&
+                                                       (age_of_cache > 15)) {
+                                               tws->current_line--;
+                                               tws_unlock(tws);
+                                               return KERN_OPERATION_TIMED_OUT;
+                                     }
+                                     if((tws->startup_name != NULL) &&
+                                                       (age_of_cache < 15)) {
+                                               /* If we are creating a */
+                                               /* cache, don't lose the */
+                                               /* early info */
+                                               tws->current_line--;
+                                               tws_unlock(tws);
+                                               return KERN_FAILURE;
+                                     }
                                      tws->lookup_count = 0;
                                      tws->insert_count = 0;
                                      set = 0;
@@ -643,44 +881,67 @@ tws_insert(
                }
        }
 
-       ele_index = 0;
-       for(i = 0; i<tws->number_of_elements; i++) {
-               if(tws->cache[set][current_line].
-                       list[ele_index].object == 0) {
-                       break;
+
+       /* set object hash element */
+       if(obj_ele == NULL) {
+               obj_ele = new_obj_hash(tws, set, index);
+               if(obj_ele == NULL) {
+                       tws->cache[set][current_line].ele_count 
+                               = tws->number_of_elements;
+                       tws_unlock(tws);
+                       return KERN_FAILURE;
                }
-               ele_index++;
-               if(ele_index >= tws->number_of_elements)
-                       ele_index = 0;
-               
        }
 
-       if(i == tws->number_of_elements) 
-               panic("tws_insert: no free elements");
+       /* set address hash element */
+       if(addr_ele == NULL) {
+               addr_ele = new_addr_hash(tws, set, alt_index);
+       }
+
+       if(target_element == NULL) {
+               ele_index = 0;
+               for(i = 0; i<tws->number_of_elements; i++) {
+                       if(tws->cache[set][current_line].
+                               list[ele_index].object == 0) {
+                               break;
+                       }
+                       ele_index++;
+                       if(ele_index >= tws->number_of_elements)
+                               ele_index = 0;
+               
+               }
+
+               if(i == tws->number_of_elements) 
+                       panic("tws_insert: no free elements");
 
+               target_element = 
+                       &(tws->cache[set][current_line].list[ele_index]);
 
-       tws->cache[set][current_line].list[ele_index].object = object;
-       tws->cache[set][current_line].list[ele_index].offset = 
-                                               offset & TWS_HASH_OFF_MASK;
-       tws->cache[set][current_line].
-               list[ele_index].page_addr = page_addr & TWS_HASH_OFF_MASK;
-       tws->cache[set][current_line].list[ele_index].map = map;
-       tws->cache[set][current_line].list[ele_index].line = 
+               tws->cache[set][current_line].ele_count++;
+       }
+
+       obj_ele->element = target_element;
+       if(addr_ele) {
+               addr_ele->element = (tws_hash_ele_t)
+                       (((unsigned int)target_element) | TWS_ADDR_HASH);
+       }
+       target_element->object = object;
+       target_element->offset = offset & TWS_HASH_OFF_MASK;
+       target_element->page_addr = 
+                       page_addr - (offset - (offset & TWS_HASH_OFF_MASK));
+       target_element->map = map;
+       target_element->line = 
                        current_line + (set * tws->number_of_lines);
-       tws->cache[set][current_line].list[ele_index].page_cache =
+       if(startup_cache_line) {
+               target_element->page_cache = startup_cache_line;
+       }
+       target_element->page_cache |=
                         1<<(((vm_offset_t)(offset & TWS_INDEX_MASK))>>12);
 
-       tws->table[k][index] = &tws->cache[set][current_line].list[ele_index];
-       for(alt_k=0; alt_k<tws->expansion_count; alt_k++) {
-               if(tws->alt_table[alt_k][alt_index] == 0) {
-                       tws->alt_table[alt_k][alt_index] = 
-                               &tws->cache[set][current_line].list[ele_index];
-                       break;
-               }
-       }
-       tws->cache[set][current_line].ele_count++;
 
        tws_unlock(tws);
+       if(ask_for_startup_cache_release)
+               return KERN_OPERATION_TIMED_OUT;
        return KERN_SUCCESS;
 }
 
@@ -756,14 +1017,19 @@ tws_build_cluster(
        task_t                  task;
        vm_object_offset_t      before = *start;
        vm_object_offset_t      after =  *end;
+       vm_object_offset_t      original_start = *start;
+       vm_object_offset_t      original_end = *end;
        vm_size_t               length =  (vm_size_t)(*end - *start);
        vm_page_t               m;
        kern_return_t           kret;
        vm_object_offset_t      object_size;
-       int             pre_heat_size;
-       int             age_of_cache;
+       int                     age_of_cache;
+       int                     pre_heat_size;
+       unsigned int            ele_cache;
+       unsigned int            end_cache = NULL;
+       unsigned int            start_cache = NULL;
 
-       if(object->private)
+       if((object->private) || !(object->pager))
                return;
 
        if (!object->internal) {
@@ -771,47 +1037,146 @@ tws_build_cluster(
                                object->pager,
                        &object_size);
        } else {
-               object_size = 0xFFFFFFFFFFFFFFFF;
+               object_size = object->size;
        }
-       /*
-        * determine age of cache in seconds
-        */
-       age_of_cache = ((sched_tick - tws->time_of_creation) >> SCHED_TICK_SHIFT);
-       
-       if (object->internal || age_of_cache > 15 || (age_of_cache > 5 && vm_page_free_count < (vm_page_free_target * 2 ))) {
-               pre_heat_size = 0;
+
+       age_of_cache = ((sched_tick 
+                       - tws->time_of_creation) >> SCHED_TICK_SHIFT);
+
+       /* When pre-heat files are not available, resort to speculation */
+       /* based on size of file */
+
+       if(tws->startup_cache || object->internal || age_of_cache > 15 || 
+               (age_of_cache > 5 && 
+                       vm_page_free_count < (vm_page_free_target * 2) )) {
+                       pre_heat_size = 0;
        } else {
-               if (object_size > (vm_object_offset_t)(1024 * 1024))
-                       pre_heat_size = 8 * PAGE_SIZE;
-               else if (object_size > (vm_object_offset_t)(128 * 1024))
-                       pre_heat_size = 4 * PAGE_SIZE;
-               else
-                       pre_heat_size = 2 * PAGE_SIZE;
+               if (object_size > (vm_object_offset_t)(1024 * 1024))
+                       pre_heat_size = 8 * PAGE_SIZE;
+               else if (object_size > (vm_object_offset_t)(128 * 1024))
+                       pre_heat_size = 4 * PAGE_SIZE;
+               else
+                       pre_heat_size = 2 * PAGE_SIZE;
+       }
+
+               if ((age_of_cache < 10) && (tws->startup_cache)) {
+               if ((max_length >= ((*end - *start) 
+                       + (32 * PAGE_SIZE))) &&
+                       (tws_test_for_community(tws, object, 
+                                       *start, 3, &ele_cache))) {
+                       int     expanded;
+                               start_cache = ele_cache;
+                       *start = *start & TWS_HASH_OFF_MASK;
+                       *end = *start + (32 * PAGE_SIZE_64);
+                       if(*end > object_size) {
+                               *end = trunc_page(object_size);
+                               max_length = 0;
+                               if(before >= *end) {
+                                       *end = after;
+                               } else {
+                                       end_cache = ele_cache;
+                               }
+                       } else {
+                               end_cache = ele_cache;
+                       }
+                       while (max_length > ((*end - *start) 
+                                               + (32 * PAGE_SIZE))) {
+                               expanded = 0;
+                               after = *end;
+                               before = *start - PAGE_SIZE_64;
+                               if((*end <= (object->size       
+                                       + (32 * PAGE_SIZE_64))) &&
+                                       (tws_test_for_community(tws, 
+                                               object, after, 
+                                               5, &ele_cache))) {
+                                       *end = after + 
+                                               (32 * PAGE_SIZE_64);
+                                       if(*end > object_size) {
+                                               *end = trunc_page(object_size);
+                                               max_length = 0;
+                                               if(*start >= *end) {
+                                                       *end = after;
+                                               }
+                                       }
+                                       end_cache = ele_cache;
+                                       expanded = 1;
+                               }
+                               if (max_length > ((*end - *start) 
+                                               + (32 * PAGE_SIZE_64))) {
+                                       break;
+                               }
+                               if((*start >= (32 * PAGE_SIZE_64)) &&
+                                       (tws_test_for_community(tws, object, 
+                                       before, 5, &ele_cache))) {
+                                       *start = before;
+                                       start_cache = ele_cache;
+                                       expanded = 1;
+                               }
+                               if(expanded == 0)
+                                       break;
+                       }
+
+                       if(start_cache != NULL) {
+                               unsigned int mask;
+
+                               for (mask = 1; mask != 0; mask = mask << 1) {
+                                       if (*start == original_start)
+                                               break;
+                                       if (!(start_cache & mask))
+                                               *start += PAGE_SIZE_64;
+                                       else
+                                               break;
+                               }
+                       }
+                       if(end_cache != NULL) {
+                               unsigned int mask;
+
+                               for (mask = 0x80000000; 
+                                               mask != 0; mask = mask >> 1) {
+                                       if (*end == original_end)
+                                                break;
+                                       if(!(end_cache & mask))
+                                               *end -= PAGE_SIZE_64;
+                                       else
+                                               break;
+                               }
+                       }
+
+                       if (*start >= *end)
+                         panic("bad clipping occurred\n");
+
+                       return;
+               }
        }
 
        while ((length < max_length) &&
                (object_size >= 
-               (object->paging_offset + after + PAGE_SIZE_64))) {
-
-               if(length >= pre_heat_size)
-                  {
-                  if(tws_lookup(tws, after, object, 
+                       (after + PAGE_SIZE_64))) {
+               if(length >= pre_heat_size) {
+                  if(tws_lookup(tws, after, object,
                                &line) != KERN_SUCCESS) {
                        vm_object_offset_t      extend;
                                
                        extend = after + PAGE_SIZE_64;
-                       if(tws_lookup(tws, extend, object, 
+                       if(tws_lookup(tws, extend, object,
                                                &line) != KERN_SUCCESS) {
                                break;
                        }
-                 }
-                }
-               if (((object->existence_map != NULL)
-                                       && (!LOOK_FOR(object, after))) ||
-                                       (vm_page_lookup(object, after)
-                                               != VM_PAGE_NULL)) {
+                  }
+               }
+
+               if ((object->existence_map != NULL)
+                                       && (!LOOK_FOR(object, after))) {
                        break;
+               } 
+
+               if (vm_page_lookup(object, after) != VM_PAGE_NULL) {
+                       /* we can bridge resident pages */
+                       after += PAGE_SIZE_64;
+                       length += PAGE_SIZE;
+                       continue;
                }
+
                if (object->internal) {
                        /*
                         * need to acquire a real page in
@@ -846,10 +1211,8 @@ tws_build_cluster(
                        break;
                before -= PAGE_SIZE_64;
 
-               if(length >= pre_heat_size)
-                  {
-
-                  if(tws_lookup(tws, before, object, 
+               if(length >= pre_heat_size) {
+                  if(tws_lookup(tws, before, object,
                                &line) != KERN_SUCCESS) {
                        vm_object_offset_t      extend;
                                
@@ -857,18 +1220,24 @@ tws_build_cluster(
                        if (extend == 0)
                                break;
                        extend -= PAGE_SIZE_64;
-                       if(tws_lookup(tws, extend, object, 
+                       if(tws_lookup(tws, extend, object,
                                        &line) != KERN_SUCCESS) {
                                break;
                        }
-                 }
-                }
-               if (((object->existence_map != NULL) 
-                                       && (!LOOK_FOR(object, before))) ||
-                                       (vm_page_lookup(object, before)
-                                               != VM_PAGE_NULL)) {
+                  }
+               }
+               if ((object->existence_map != NULL) 
+                                       && (!LOOK_FOR(object, before))) {
                        break;
                }
+
+               if (vm_page_lookup(object, before) != VM_PAGE_NULL) {
+                       /* we can bridge resident pages */
+                       *start -= PAGE_SIZE_64;
+                       length += PAGE_SIZE;
+                       continue;
+               }
+
                if (object->internal) {
                        /*
                         * need to acquire a real page in
@@ -1029,6 +1398,441 @@ tws_line_signal(
        vm_map_unlock(map);
 }
 
+/* tws locked on entry */
+
+tws_startup_t
+tws_create_startup_list(
+       tws_hash_t      tws)
+{
+
+       tws_startup_t           startup;
+       unsigned int            i,j,k;
+       unsigned int            total_elements;
+       unsigned int            startup_size;
+       unsigned int            sindex;
+       unsigned int            hash_index;
+       tws_startup_ptr_t       element;
+
+       total_elements = tws->expansion_count *
+                       (tws->number_of_lines * tws->number_of_elements);
+
+       startup_size = sizeof(struct tws_startup) 
+                       + (total_elements * sizeof(tws_startup_ptr_t *))
+                       + (total_elements * sizeof(struct tws_startup_ptr))
+                       + (total_elements * sizeof(struct tws_startup_ele));
+       startup = (tws_startup_t)(kalloc(startup_size));
+
+       if(startup == NULL)
+               return startup;
+
+       bzero((char *) startup, startup_size);
+
+       startup->table = (tws_startup_ptr_t *)
+               (((int)startup) + (sizeof(struct tws_startup)));
+       startup->ele = (struct tws_startup_ptr *)
+                       (((vm_offset_t)startup->table) + 
+                       (total_elements * sizeof(tws_startup_ptr_t)));
+
+       startup->array = (struct tws_startup_ele *)
+                       (((vm_offset_t)startup->ele) + 
+                       (total_elements * sizeof(struct tws_startup_ptr)));
+
+       startup->tws_hash_size = startup_size;
+       startup->ele_count = 0;  /* burn first hash ele, else we can't tell from zero */
+       startup->array_size = total_elements;
+       startup->hash_count = 1;
+
+       sindex = 0;
+       
+       
+       for(i = 0; i<tws->number_of_lines; i++) {
+          for(j = 0; j<tws->number_of_elements; j++) {
+             for(k = 0; k<tws->expansion_count; k++) {
+               tws_hash_ele_t          entry;
+               unsigned int            hash_retry;
+               vm_offset_t             addr;
+
+               entry = &tws->cache[k][i].list[j];
+               addr = entry->page_addr;
+               hash_retry = 0;
+               if(entry->object != 0) {
+                       /* get a hash element */
+                       hash_index = do_startup_hash(addr, 
+                                               startup->array_size);
+
+                       if(startup->hash_count < total_elements) {
+                               element = &(startup->ele[startup->hash_count]);
+                               startup->hash_count += 1;
+                       } else {
+                               /* exit we're out of elements */
+                               break;
+                       }
+                       /* place the hash element */
+                       element->next = startup->table[hash_index];
+                       startup->table[hash_index] = (tws_startup_ptr_t)
+                               ((int)element - (int)&startup->ele[0]);
+
+                       /* set entry OFFSET in hash element */
+                       element->element =  (tws_startup_ele_t)
+                               ((int)&startup->array[sindex] - 
+                                               (int)&startup->array[0]);
+               
+                       startup->array[sindex].page_addr = entry->page_addr;
+                       startup->array[sindex].page_cache = entry->page_cache;
+                       startup->ele_count++;
+                       sindex++;
+               
+               }
+            }
+          }
+       }
+
+       return startup;
+}
+
+
+/*
+ * Returns an entire cache line.  The line is deleted from the startup
+ * cache on return. The caller can check startup->ele_count for an empty
+ * list. Access synchronization is the responsibility of the caller.
+ */
+
+unsigned int
+tws_startup_list_lookup(
+       tws_startup_t   startup,
+       vm_offset_t     addr)
+{
+       unsigned int            hash_index;
+       unsigned int            page_cache_bits;
+       unsigned int            startup_shift;
+       tws_startup_ele_t       entry;
+       vm_offset_t             next_addr;
+       tws_startup_ptr_t       element;
+       tws_startup_ptr_t       base_ele;
+       tws_startup_ptr_t       *previous_ptr;
+
+       page_cache_bits = 0;
+
+       hash_index = do_startup_hash(addr, startup->array_size);
+
+       if(((unsigned int)&(startup->table[hash_index])) >= startup->tws_hash_size) {
+               return page_cache_bits = 0;
+       }
+       element = (tws_startup_ptr_t)((int)startup->table[hash_index] +
+                       (int)&startup->ele[0]);
+       base_ele = element;
+       previous_ptr = &(startup->table[hash_index]);
+       while(element > &startup->ele[0]) {
+               if (((int)element + sizeof(struct tws_startup_ptr))
+                       > ((int)startup + startup->tws_hash_size))  {
+                       return page_cache_bits;
+               }
+               entry = (tws_startup_ele_t)
+                       ((int)element->element 
+                               + (int)&startup->array[0]);
+               if((((int)entry + sizeof(struct tws_startup_ele))
+                       > ((int)startup + startup->tws_hash_size)) 
+                               || ((int)entry < (int)startup))  {
+                       return page_cache_bits;
+               }
+               if ((addr >= entry->page_addr) && 
+                       (addr <= (entry->page_addr + 0x1F000))) {
+                       startup_shift = (addr - entry->page_addr)>>12;
+                       page_cache_bits |= entry->page_cache >> startup_shift;
+                       /* don't dump the pages, unless the addresses */
+                       /* line up perfectly.  The cache may be used */
+                       /* by other mappings */
+                       entry->page_cache &= (1 << startup_shift) - 1;
+                       if(addr == entry->page_addr) {
+                               if(base_ele == element) {
+                                       base_ele = (tws_startup_ptr_t)
+                                               ((int)element->next 
+                                               + (int)&startup->ele[0]);
+                                       startup->table[hash_index] = element->next;
+                                       element = base_ele;
+                               } else {
+                                       *previous_ptr = element->next;
+                                       element = (tws_startup_ptr_t)
+                                               ((int)*previous_ptr 
+                                               + (int)&startup->ele[0]);
+                               }
+                               entry->page_addr = 0;
+                               startup->ele_count--;
+                               continue;
+                       }
+               }
+               next_addr = addr + 0x1F000;
+               if ((next_addr >= entry->page_addr) && 
+                       (next_addr <= (entry->page_addr + 0x1F000))) {
+                       startup_shift = (next_addr - entry->page_addr)>>12;
+                       page_cache_bits |= entry->page_cache << (0x1F - startup_shift);
+                       entry->page_cache &= ~((1 << (startup_shift + 1)) - 1);
+                       if(entry->page_cache == 0) {
+                               if(base_ele == element) {
+                                       base_ele = (tws_startup_ptr_t)
+                                               ((int)element->next 
+                                               + (int)&startup->ele[0]);
+                                       startup->table[hash_index] = element->next;
+                                       element = base_ele;
+                               } else {
+                                       *previous_ptr = element->next;
+                                       element = (tws_startup_ptr_t)
+                                               ((int)*previous_ptr 
+                                               + (int)&startup->ele[0]);
+                               }
+                               entry->page_addr = 0;
+                               startup->ele_count--;
+                               continue;
+                       }
+               }
+               previous_ptr = &(element->next);
+               element = (tws_startup_ptr_t) 
+                       ((int) element->next + (int) &startup->ele[0]);
+       }
+
+       return page_cache_bits;
+}
+
+kern_return_t
+tws_send_startup_info(
+               task_t          task)
+{
+
+       tws_hash_t              tws;
+       tws_startup_t           scache;
+
+       task_lock(task);
+       tws = (tws_hash_t)task->dynamic_working_set;
+       task_unlock(task);
+       if(tws == NULL) {
+               return KERN_FAILURE;
+       }
+       return tws_internal_startup_send(tws);
+}
+
+
+kern_return_t
+tws_internal_startup_send(
+               tws_hash_t      tws)
+{
+
+       tws_startup_t           scache;
+
+       if(tws == NULL) {
+               return KERN_FAILURE;
+       }
+       tws_lock(tws);
+       /* used to signal write or release depending on state of tws */
+       if(tws->startup_cache) {
+               vm_offset_t     startup_buf;
+               vm_size_t       size;
+               startup_buf = (vm_offset_t)tws->startup_cache;
+               size = tws->startup_cache->tws_hash_size;
+               tws->startup_cache = 0;
+               tws_unlock(tws);
+               kmem_free(kernel_map, startup_buf, size);
+               return KERN_SUCCESS;
+       }
+       if(tws->startup_name == NULL) {
+               tws_unlock(tws);
+               return KERN_FAILURE;
+       }
+       scache = tws_create_startup_list(tws);
+       if(scache == NULL)
+               return KERN_FAILURE;
+       bsd_write_page_cache_file(tws->uid, tws->startup_name, 
+                               scache, scache->tws_hash_size, 
+                               tws->mod, tws->fid);
+       kfree((vm_offset_t)scache, scache->tws_hash_size);
+       kfree((vm_offset_t) tws->startup_name, tws->startup_name_length);
+       tws->startup_name = NULL;
+       tws_unlock(tws);
+       return KERN_SUCCESS;
+}
+
+kern_return_t
+tws_handle_startup_file(
+               task_t                  task,
+               unsigned int            uid,
+               char                    *app_name,
+               vm_offset_t             app_vp,
+               boolean_t               *new_info)
+
+{
+               tws_startup_t   startup;
+               vm_offset_t     cache_size;     
+               kern_return_t   error;
+               int             fid;
+               int             mod;
+               
+               *new_info = FALSE;
+               /* don't pre-heat kernel task */
+               if(task == kernel_task)
+                       return KERN_SUCCESS;
+               error = bsd_read_page_cache_file(uid, &fid, 
+                                       &mod, app_name, 
+                                       app_vp, &startup, 
+                                       &cache_size);
+               if(error) {
+                       return KERN_FAILURE;
+               }
+               if(startup == NULL) {
+                       /* Entry for app does not exist, make */
+                       /* one */
+                       /* we will want our own copy of the shared */
+                       /* regions to pick up a true picture of all */
+                       /* the pages we will touch. */
+                       if((lsf_zone->count * lsf_zone->elem_size) 
+                                               > (lsf_zone->max_size >> 1)) {
+                               /* We don't want to run out of shared memory */
+                               /* map entries by starting too many private versions */
+                               /* of the shared library structures */
+                               return KERN_SUCCESS;
+                       }
+                       *new_info = TRUE;
+                       error = tws_write_startup_file(task, 
+                                       fid, mod, app_name, uid);
+                       if(error)
+                               return error;
+                       /* use the mod in the write case as an init */
+                       /* flag */
+                       mod = 0;
+
+               } else {
+                       error = tws_read_startup_file(task, 
+                                               (tws_startup_t)startup, 
+                                               cache_size);
+                       if(error) {
+                               kmem_free(kernel_map, 
+                                       (vm_offset_t)startup, cache_size); 
+                               return error;
+                       }
+               }
+               return KERN_SUCCESS;
+}
+
+kern_return_t
+tws_write_startup_file(
+               task_t                  task,
+               int                     fid,
+               int                     mod,
+               char                    *name,
+               unsigned int            uid)
+{
+               tws_hash_t              tws;
+               unsigned int            string_length;
+
+               string_length = strlen(name);
+
+               task_lock(task);
+               tws = (tws_hash_t)task->dynamic_working_set;
+
+               task_unlock(task);
+               if(tws == NULL) {
+                       /* create a dynamic working set of normal size */
+                       task_working_set_create(task, 0,
+                                               0, TWS_HASH_STYLE_DEFAULT);
+               }
+               tws_lock(tws);
+
+               if(tws->startup_name != NULL) {
+                       tws_unlock(tws);
+                       return KERN_FAILURE;
+               }
+
+               tws->startup_name = (char *)
+                       kalloc((string_length + 1) * (sizeof(char)));
+               if(tws->startup_name == NULL) {
+                       tws_unlock(tws);
+                       return KERN_FAILURE;
+               }
+
+               bcopy(name, (char *)tws->startup_name, string_length + 1);
+               tws->startup_name_length = (string_length + 1) * sizeof(char);
+               tws->uid = uid;
+               tws->fid = fid;
+               tws->mod = mod;
+
+               tws_unlock(tws);
+               return KERN_SUCCESS;
+}
+
+kern_return_t
+tws_read_startup_file(
+               task_t                  task,
+               tws_startup_t           startup,
+               vm_offset_t             cache_size)
+{
+               tws_hash_t              tws;
+               int                     error;
+               int                     lines;
+               int                     old_exp_count;
+
+               task_lock(task);
+               tws = (tws_hash_t)task->dynamic_working_set;
+
+               if(cache_size < sizeof(struct tws_hash)) {
+                       task_unlock(task);
+                       kmem_free(kernel_map, (vm_offset_t)startup, cache_size); 
+                       return(KERN_SUCCESS);
+               }
+
+               /* create a dynamic working set to match file size */
+               lines = (cache_size - sizeof(struct tws_hash))/TWS_ARRAY_SIZE;
+               /* we now need to divide out element size and word size */
+               /* all fields are 4 bytes.  There are 8 bytes in each hash element */
+               /* entry, 4 bytes in each table ptr location and 8 bytes in each */
+               /* page_cache entry, making a total of 20 bytes for each entry */
+               lines = (lines/(20));
+               if(lines <= TWS_SMALL_HASH_LINE_COUNT) {
+                       lines = TWS_SMALL_HASH_LINE_COUNT;
+                       task_unlock(task);
+                       kmem_free(kernel_map, (vm_offset_t)startup, cache_size); 
+                       return(KERN_SUCCESS);
+               } else {
+                       old_exp_count = lines/TWS_HASH_LINE_COUNT;
+                       if((old_exp_count * TWS_HASH_LINE_COUNT) != lines) {
+                               lines = (old_exp_count + 1) 
+                                               * TWS_HASH_LINE_COUNT;
+                       }
+                       if(tws == NULL) {
+                               task_working_set_create(task, lines, 
+                                               0, TWS_HASH_STYLE_DEFAULT);
+                               task_unlock(task);
+                       } else {
+                               task_unlock(task);
+                               tws_expand_working_set(
+                                       (vm_offset_t)tws, lines, TRUE);
+                       }
+               }
+               
+
+               tws_lock(tws);
+               
+               if(tws->startup_cache != NULL) {
+                       tws_unlock(tws);
+                       return KERN_FAILURE;
+               }
+
+
+               /* now need to fix up internal table pointers */
+               startup->table = (tws_startup_ptr_t *)
+                       (((int)startup) + (sizeof(struct tws_startup)));
+               startup->ele = (struct tws_startup_ptr *)
+                       (((vm_offset_t)startup->table) + 
+                       (startup->array_size * sizeof(tws_startup_ptr_t)));
+               startup->array = (struct tws_startup_ele *)
+                       (((vm_offset_t)startup->ele) + 
+                       (startup->array_size * sizeof(struct tws_startup_ptr)));
+               /* the allocation size and file size should be the same */
+               /* just in case their not, make sure we dealloc correctly  */
+               startup->tws_hash_size = cache_size;
+
+
+               tws->startup_cache = startup;
+               tws_unlock(tws);
+               return KERN_SUCCESS;
+}
 
 
 void
@@ -1037,6 +1841,15 @@ tws_hash_destroy(tws_hash_t      tws)
        int     i,k;
        vm_size_t       cache_size;
 
+       if(tws->startup_cache != NULL) {
+               kmem_free(kernel_map,
+                       (vm_offset_t)tws->startup_cache, 
+                       tws->startup_cache->tws_hash_size);
+               tws->startup_cache = NULL;
+       }
+       if(tws->startup_name != NULL) {
+               tws_internal_startup_send(tws);
+       }
        for (i=0; i<tws->number_of_lines; i++) {
                for(k=0; k<tws->expansion_count; k++) {
                        /* clear the object refs */
@@ -1046,16 +1859,25 @@ tws_hash_destroy(tws_hash_t     tws)
        i = 0;
        while (i < tws->expansion_count) {
                
-               kfree((vm_offset_t)tws->table[i], sizeof(tws_hash_ele_t) 
-                               * 2 * tws->number_of_lines 
+               kfree((vm_offset_t)tws->table[i], sizeof(tws_hash_ptr_t) 
+                               * tws->number_of_lines 
+                               * tws->number_of_elements);
+               kfree((vm_offset_t)tws->table_ele[i], 
+                               sizeof(struct tws_hash_ptr) 
+                               * tws->number_of_lines 
                                * tws->number_of_elements);
-               kfree((vm_offset_t)tws->alt_table[i], sizeof(tws_hash_ele_t) 
-                               * 2 * tws->number_of_lines 
+               kfree((vm_offset_t)tws->alt_ele[i], 
+                               sizeof(struct tws_hash_ptr) 
+                               * tws->number_of_lines 
                                * tws->number_of_elements);
                kfree((vm_offset_t)tws->cache[i], sizeof(struct tws_hash_line) 
                                * tws->number_of_lines);
                i++;
        }
+       if(tws->startup_name != NULL) {
+               kfree((vm_offset_t)tws->startup_name, 
+                               tws->startup_name_length);
+       }
        kfree((vm_offset_t)tws, sizeof(struct tws_hash));
 }
 
@@ -1101,3 +1923,280 @@ task_working_set_create(
        task_unlock(task);
        return KERN_SUCCESS;
 }
+
+
+/* Internal use only routines */
+
+
+/* 
+ * internal sub-function for address space lookup
+ * returns the target element and the address of the
+ * previous pointer  The previous pointer is the address 
+ * of the pointer pointing to the target element.
+ * TWS must be locked
+ */
+
+void
+tws_traverse_address_hash_list (
+       tws_hash_t              tws, 
+       unsigned int            index,
+       vm_offset_t             page_addr,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       vm_map_t                map,
+       tws_hash_ptr_t          *target_ele,
+       tws_hash_ptr_t          **previous_ptr,
+       tws_hash_ptr_t          **free_list,
+       unsigned int            exclusive_addr)
+{
+       int     k;
+       tws_hash_ptr_t  cache_ele;
+       tws_hash_ptr_t  base_ele;
+
+       *target_ele = NULL;
+       *previous_ptr = NULL;
+
+       for(k=0; k<tws->expansion_count; k++) {
+               tws_hash_ele_t ele;
+               cache_ele = tws->table[k][index];
+               base_ele = cache_ele;
+               *previous_ptr = (tws_hash_ptr_t *)&(tws->table[k][index]);
+               while(cache_ele != NULL) {
+                       if(((unsigned int)
+                               cache_ele->element & TWS_ADDR_HASH) == 0) {
+                               *previous_ptr = (tws_hash_ptr_t *)&(cache_ele->next);
+                               cache_ele = cache_ele->next;
+                               continue;
+                       }
+                       ele = (tws_hash_ele_t)((unsigned int)
+                               cache_ele->element & ~TWS_ADDR_HASH);
+                       if ((ele == 0) || (ele->object == 0)) {
+                               /* A little clean-up of empty elements */
+                               cache_ele->element = 0;
+                               if(base_ele == cache_ele) {
+                                       base_ele = cache_ele->next;
+                                       tws->table[k][index] = cache_ele->next;
+                                       cache_ele->next = tws->free_hash_ele[k];
+                                       tws->free_hash_ele[k] = cache_ele;
+                                       cache_ele = base_ele;
+                               } else {
+                                       **previous_ptr = cache_ele->next;
+                                       cache_ele->next = tws->free_hash_ele[k];
+                                       tws->free_hash_ele[k] = cache_ele;
+                                       cache_ele = **previous_ptr;
+                               }
+                               continue;
+                       }
+       
+                       if ((ele->page_addr <= page_addr) 
+                               && (page_addr <= (ele->page_addr + 
+                               (vm_offset_t)TWS_INDEX_MASK))
+                               && ((object == NULL) 
+                                       || ((object == ele->object)
+                                       && (offset == ele->offset)
+                                       && (map == ele->map)))) {
+                               if(exclusive_addr) {
+                                       int delta;
+                                       delta = ((page_addr - ele->page_addr)
+                                        >> 12);
+                                       if((1 << delta) & ele->page_cache) {
+                                               /* We've found a match */
+                                               *target_ele = cache_ele;
+                                               *free_list = 
+                                                  (tws_hash_ptr_t *)
+                                                  &(tws->free_hash_ele[k]);
+                                               return;
+                                       }
+                               } else {
+                                       /* We've found a match */
+                                       *target_ele = cache_ele;
+                                       *free_list = (tws_hash_ptr_t *)
+                                               &(tws->free_hash_ele[k]);
+                                       return;
+                               }
+                       }
+                       *previous_ptr = (tws_hash_ptr_t *)&(cache_ele->next);
+                       cache_ele = cache_ele->next;
+               }
+       }
+}
+
+
+/* 
+ * internal sub-function for object space lookup
+ * returns the target element and the address of the
+ * previous pointer  The previous pointer is the address 
+ * of the pointer pointing to the target element.
+ * TWS must be locked
+ */
+
+
+void
+tws_traverse_object_hash_list (
+       tws_hash_t              tws, 
+       unsigned int            index,
+       vm_object_t             object,
+       vm_object_offset_t      offset,
+       unsigned int            page_mask,
+       tws_hash_ptr_t          *target_ele,
+       tws_hash_ptr_t          **previous_ptr,
+       tws_hash_ptr_t          **free_list)
+{
+       int     k;
+       tws_hash_ptr_t  cache_ele;
+       tws_hash_ptr_t  base_ele;
+
+       *target_ele = NULL;
+       *previous_ptr = NULL;
+
+       for(k=0; k<tws->expansion_count; k++) {
+               cache_ele = tws->table[k][index];
+               base_ele = cache_ele;
+               *previous_ptr = &(tws->table[k][index]);
+               while(cache_ele != NULL) {
+                       if((((unsigned int)cache_ele->element) 
+                                               & TWS_ADDR_HASH) != 0) {
+                               *previous_ptr = &(cache_ele->next);
+                               cache_ele = cache_ele->next;
+                               continue;
+                       }
+                       if ((cache_ele->element == 0) || 
+                               (cache_ele->element->object == 0)) {
+                               /* A little clean-up of empty elements */
+                               cache_ele->element = 0;
+                               if(base_ele == cache_ele) {
+                                       base_ele = cache_ele->next;
+                                       tws->table[k][index] = cache_ele->next;
+                                       cache_ele->next = tws->free_hash_ele[k];
+                                       tws->free_hash_ele[k] = cache_ele;
+                                       cache_ele = tws->table[k][index];
+                               } else {
+                                       **previous_ptr = cache_ele->next;
+                                       cache_ele->next = tws->free_hash_ele[k];
+                                       tws->free_hash_ele[k] = cache_ele;
+                                       cache_ele = **previous_ptr;
+                               }
+                               continue;
+                       }
+                       if ((cache_ele->element->object == object)
+                               && (cache_ele->element->offset == 
+                               (offset - (offset & ~TWS_HASH_OFF_MASK)))) {
+                               if((cache_ele->element->page_cache & page_mask) 
+                                       || (page_mask == 0xFFFFFFFF)) {
+                                       /* We've found a match */
+                                       *target_ele = cache_ele;
+                                       *free_list = &(tws->free_hash_ele[k]);
+                                       return;
+                               }
+                       }
+                       *previous_ptr = (tws_hash_ptr_t *)&(cache_ele->next);
+                       cache_ele = cache_ele->next;
+               }
+       }
+}
+
+
+/*
+ * For a given object/offset, discover whether the indexed 32 page frame 
+ * containing the object/offset exists and if their are at least threshold
+ * pages present.  Returns true if population meets threshold.
+ */
+int 
+tws_test_for_community(
+               tws_hash_t              tws, 
+               vm_object_t             object, 
+               vm_object_offset_t      offset, 
+               unsigned int            threshold, 
+               unsigned int            *page_mask) 
+{
+       int     index;
+       tws_hash_ptr_t  cache_ele;
+       tws_hash_ptr_t  *trailer;
+       tws_hash_ptr_t  *free_list;
+       int             community = 0;
+
+       index = do_tws_hash(object, offset, 
+                       tws->number_of_elements, tws->number_of_lines);
+       tws_traverse_object_hash_list(tws, index, object, offset, 0xFFFFFFFF,
+               &cache_ele, &trailer, &free_list);
+
+       if(cache_ele != NULL) {
+               int i;
+               int ctr;
+               ctr = 0;
+               for(i=1; i!=0; i=i<<1) {
+                       if(i & cache_ele->element->page_cache)
+                               ctr++;
+                       if(ctr == threshold) {
+                               community = 1;
+                               *page_mask = cache_ele->element->page_cache;
+                               break;
+                       }
+               }
+       }
+
+       return community;
+       
+}
+
+
+/* 
+ * Gets new hash element for object hash from free pools
+ * TWS must be locked
+ */
+
+tws_hash_ptr_t
+new_obj_hash(
+       tws_hash_t tws, 
+       unsigned int set, 
+       unsigned int index)
+{
+       tws_hash_ptr_t element;
+
+       if(tws->obj_free_count[set] < tws->number_of_lines * tws->number_of_elements) {
+               element = &(tws->table_ele[set][tws->obj_free_count[set]]);
+               tws->obj_free_count[set]+=1;
+       } else if(tws->free_hash_ele[set] == NULL) {
+               return NULL;
+       } else {
+               element = tws->free_hash_ele[set];
+               if(element == NULL)
+                       return element;
+               tws->free_hash_ele[set] = tws->free_hash_ele[set]->next;
+       }
+       element->element = 0;
+       element->next = tws->table[set][index];
+       tws->table[set][index] = element;
+       return element;
+}
+
+/* 
+ * Gets new hash element for addr hash from free pools
+ * TWS must be locked
+ */
+
+tws_hash_ptr_t
+new_addr_hash(
+       tws_hash_t tws, 
+       unsigned int set, 
+       unsigned int index)
+{
+       tws_hash_ptr_t element;
+
+       if(tws->addr_free_count[set] 
+                       < tws->number_of_lines * tws->number_of_elements) {
+               element = &(tws->alt_ele[set][tws->addr_free_count[set]]);
+               tws->addr_free_count[set]+=1;
+       } else if(tws->free_hash_ele[set] == NULL) {
+               return NULL;
+       } else {
+               element = tws->free_hash_ele[set];
+               if(element == NULL)
+                       return element;
+               tws->free_hash_ele[set] = tws->free_hash_ele[set]->next;
+       }
+       element->element = (tws_hash_ele_t)TWS_ADDR_HASH;
+       element->next = tws->table[set][index];
+       tws->table[set][index] = element;
+       return element;
+}