[lc-checkins] CVS: linux/include/linux comp_cache.h,1.38,1.39

[Rodrigo S. de C. <rc...@us...>]

Update of /cvsroot/linuxcompressed/linux/include/linux
In directory usw-pr-cvs1:/tmp/cvs-serv31165/include/linux

Modified Files:
	comp_cache.h 
Log Message:
More changes regarding performance optimization.

- avl tree is finally removed. Now there's a new hash table for compressed
cache entries, what improved our cache performance. comp_cache_struct size
was decreased by 10 bytes with this change (actually 8 due to C struct
padding).

- search for duplicated fragments in get_comp_cache_page() was deleted since
it does not make sense any longer. Calls to _find_nolock_comp_page() have
fallen dramatically.

- comp_cache_notree() was renamed to comp_cache_nohash().



Index: comp_cache.h
===================================================================
RCS file: /cvsroot/linuxcompressed/linux/include/linux/comp_cache.h,v
retrieving revision 1.38
retrieving revision 1.39
diff -C2 -r1.38 -r1.39
*** comp_cache.h	2002/01/04 22:24:07	1.38
--- comp_cache.h	2002/01/07 17:48:29	1.39
***************
*** 2,6 ****
   * linux/mm/comp_cache.h
   *
!  * Time-stamp: <2002-01-04 19:31:48 rcastro>
   *  
   * Linux Virtual Memory Compressed Cache
--- 2,6 ----
   * linux/mm/comp_cache.h
   *
!  * Time-stamp: <2002-01-07 15:33:53 rcastro>
   *  
   * Linux Virtual Memory Compressed Cache
***************
*** 36,46 ****
  extern unsigned long real_num_comp_pages, new_num_comp_pages, max_num_comp_pages;
  
- struct avl_info {
- 	short comp_avl_height;
- 	struct comp_cache_struct * comp_avl_left;
- 	struct comp_cache_struct * comp_avl_right;
- 	struct list_head avl_list;
- };
- 
  struct pte_list {
  	struct pte_list * next;
--- 36,39 ----
***************
*** 75,83 ****
  
  	short free_space;	
- 	struct avl_info avl_free_space;
  
  	struct list_head fragments;
  
  	unsigned long flags;
  } comp_cache_t;
  
--- 68,78 ----
  
  	short free_space;	
  
  	struct list_head fragments;
  
  	unsigned long flags;
+ 
+ 	struct comp_cache_struct * next_hash;
+ 	struct comp_cache_struct ** pprev_hash;
  } comp_cache_t;
  
***************
*** 129,150 ****
  
  #endif
- 
- /* avl.c */
- extern comp_cache_t * comp_avl_free_space;
- 
- void comp_avl_insert (comp_cache_t *, comp_cache_t **, unsigned long, unsigned long);
- int  comp_avl_remove (comp_cache_t *, comp_cache_t **, unsigned long, unsigned long);
- comp_cache_t * comp_search_avl_tree(unsigned short, comp_cache_t *, unsigned long, unsigned long);
- 
- #define search_avl_tree_free_space(size) \
-   comp_search_avl_tree(size, comp_avl_free_space, member_offset(free_space), member_offset(avl_free_space))
- 
- #define avl_insert_free_space(comp_page) \
-   comp_avl_insert(comp_page, &comp_avl_free_space, member_offset(free_space), member_offset(avl_free_space))
- 
- #define avl_remove_free_space(comp_page) \
-   comp_avl_remove(comp_page, &comp_avl_free_space, member_offset(free_space), member_offset(avl_free_space))
  
! /* Comp Fragment Entry Flags */
  #define CF_Freed                  0
  #define CF_SwapBuffer             1
--- 124,129 ----
  
  #endif
  
! /* comp fragment entry flags */
  #define CF_Freed                  0
  #define CF_SwapBuffer             1
***************
*** 494,497 ****
--- 473,493 ----
  inline void add_fragment_to_hash_table(comp_cache_fragment_t *);
  inline void remove_fragment_from_hash_table(comp_cache_fragment_t *);
+ 
+ #define FREE_SPACE_INTERVAL  100
+ #define FREE_SPACE_HASH_SIZE ((int) (PAGE_SIZE/FREE_SPACE_INTERVAL) + 2)
+ static inline int free_space_hashfn(int free_space)
+ {
+ 	if (!free_space)
+ 		return 0;
+ 
+ 	free_space -= (free_space % FREE_SPACE_INTERVAL);
+ 
+ 	return (free_space/FREE_SPACE_INTERVAL + 1);
+ }
+ 
+ inline void add_comp_page_to_hash_table(comp_cache_t *);
+ inline void remove_comp_page_from_hash_table(comp_cache_t *);
+ comp_cache_t * search_comp_page_free_space(int);
+ 
  
  extern struct list_head lru_queue;