[PATCH v5 04/12] zsmalloc: keep max_object in size_class

[Minchan Kim]

Every zspage in a size_class has same number of max objects so
we could move it to a size_class.

Reviewed-by: Sergey Senozhatsky 
Signed-off-by: Minchan Kim 
---
 mm/zsmalloc.c | 32 +++-
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 3d6d3dae505a..3c2574be8cee 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -32,8 +32,6 @@
  * page->freelist: points to the first free object in zspage.
  * Free objects are linked together using in-place
  * metadata.
- * page->objects: maximum number of objects we can store in this
- * zspage (class->zspage_order * PAGE_SIZE / class->size)
  * page->lru: links together first pages of various zspages.
  * Basically forming list of zspages in a fullness group.
  * page->mapping: class index and fullness group of the zspage
@@ -211,6 +209,7 @@ struct size_class {
 * of ZS_ALIGN.
 */
int size;
+   int objs_per_zspage;
unsigned int index;
 
struct zs_size_stat stats;
@@ -627,21 +626,22 @@ static inline void zs_pool_stat_destroy(struct zs_pool 
*pool)
  * the pool (not yet implemented). This function returns fullness
  * status of the given page.
  */
-static enum fullness_group get_fullness_group(struct page *first_page)
+static enum fullness_group get_fullness_group(struct size_class *class,
+   struct page *first_page)
 {
-   int inuse, max_objects;
+   int inuse, objs_per_zspage;
enum fullness_group fg;
 
VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
inuse = first_page->inuse;
-   max_objects = first_page->objects;
+   objs_per_zspage = class->objs_per_zspage;
 
if (inuse == 0)
fg = ZS_EMPTY;
-   else if (inuse == max_objects)
+   else if (inuse == objs_per_zspage)
fg = ZS_FULL;
-   else if (inuse <= 3 * max_objects / fullness_threshold_frac)
+   else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac)
fg = ZS_ALMOST_EMPTY;
else
fg = ZS_ALMOST_FULL;
@@ -728,7 +728,7 @@ static enum fullness_group fix_fullness_group(struct 
size_class *class,
enum fullness_group currfg, newfg;
 
get_zspage_mapping(first_page, _idx, );
-   newfg = get_fullness_group(first_page);
+   newfg = get_fullness_group(class, first_page);
if (newfg == currfg)
goto out;
 
@@ -1011,9 +1011,6 @@ static struct page *alloc_zspage(struct size_class 
*class, gfp_t flags)
init_zspage(class, first_page);
 
first_page->freelist = location_to_obj(first_page, 0);
-   /* Maximum number of objects we can store in this zspage */
-   first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size;
-
error = 0; /* Success */
 
 cleanup:
@@ -1241,11 +1238,11 @@ static bool can_merge(struct size_class *prev, int 
size, int pages_per_zspage)
return true;
 }
 
-static bool zspage_full(struct page *first_page)
+static bool zspage_full(struct size_class *class, struct page *first_page)
 {
VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
-   return first_page->inuse == first_page->objects;
+   return first_page->inuse == class->objs_per_zspage;
 }
 
 unsigned long zs_get_total_pages(struct zs_pool *pool)
@@ -1631,7 +1628,7 @@ static int migrate_zspage(struct zs_pool *pool, struct 
size_class *class,
}
 
/* Stop if there is no more space */
-   if (zspage_full(d_page)) {
+   if (zspage_full(class, d_page)) {
unpin_tag(handle);
ret = -ENOMEM;
break;
@@ -1690,7 +1687,7 @@ static enum fullness_group putback_zspage(struct zs_pool 
*pool,
 {
enum fullness_group fullness;
 
-   fullness = get_fullness_group(first_page);
+   fullness = get_fullness_group(class, first_page);
insert_zspage(class, fullness, first_page);
set_zspage_mapping(first_page, class->index, fullness);
 
@@ -1939,8 +1936,9 @@ struct zs_pool *zs_create_pool(const char *name)
class->size = size;
class->index = i;
class->pages_per_zspage = pages_per_zspage;
-   if (pages_per_zspage == 1 &&
-   get_maxobj_per_zspage(size, pages_per_zspage) == 1)
+   class->objs_per_zspage = class->pages_per_zspage *
+   PAGE_SIZE / class->size;
+   if (pages_per_zspage == 1 && class->objs_per_zspage == 1)
class->huge = true;
spin_lock_init(>lock);
pool->size_class[i] = class;
-- 
1.9.1

[PATCH v5 04/12] zsmalloc: keep max_object in size_class

[Minchan Kim]

Every zspage in a size_class has same number of max objects so
we could move it to a size_class.

Reviewed-by: Sergey Senozhatsky 
Signed-off-by: Minchan Kim 
---
 mm/zsmalloc.c | 32 +++-
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 3d6d3dae505a..3c2574be8cee 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -32,8 +32,6 @@
  * page->freelist: points to the first free object in zspage.
  * Free objects are linked together using in-place
  * metadata.
- * page->objects: maximum number of objects we can store in this
- * zspage (class->zspage_order * PAGE_SIZE / class->size)
  * page->lru: links together first pages of various zspages.
  * Basically forming list of zspages in a fullness group.
  * page->mapping: class index and fullness group of the zspage
@@ -211,6 +209,7 @@ struct size_class {
 * of ZS_ALIGN.
 */
int size;
+   int objs_per_zspage;
unsigned int index;
 
struct zs_size_stat stats;
@@ -627,21 +626,22 @@ static inline void zs_pool_stat_destroy(struct zs_pool 
*pool)
  * the pool (not yet implemented). This function returns fullness
  * status of the given page.
  */
-static enum fullness_group get_fullness_group(struct page *first_page)
+static enum fullness_group get_fullness_group(struct size_class *class,
+   struct page *first_page)
 {
-   int inuse, max_objects;
+   int inuse, objs_per_zspage;
enum fullness_group fg;
 
VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
inuse = first_page->inuse;
-   max_objects = first_page->objects;
+   objs_per_zspage = class->objs_per_zspage;
 
if (inuse == 0)
fg = ZS_EMPTY;
-   else if (inuse == max_objects)
+   else if (inuse == objs_per_zspage)
fg = ZS_FULL;
-   else if (inuse <= 3 * max_objects / fullness_threshold_frac)
+   else if (inuse <= 3 * objs_per_zspage / fullness_threshold_frac)
fg = ZS_ALMOST_EMPTY;
else
fg = ZS_ALMOST_FULL;
@@ -728,7 +728,7 @@ static enum fullness_group fix_fullness_group(struct 
size_class *class,
enum fullness_group currfg, newfg;
 
get_zspage_mapping(first_page, _idx, );
-   newfg = get_fullness_group(first_page);
+   newfg = get_fullness_group(class, first_page);
if (newfg == currfg)
goto out;
 
@@ -1011,9 +1011,6 @@ static struct page *alloc_zspage(struct size_class 
*class, gfp_t flags)
init_zspage(class, first_page);
 
first_page->freelist = location_to_obj(first_page, 0);
-   /* Maximum number of objects we can store in this zspage */
-   first_page->objects = class->pages_per_zspage * PAGE_SIZE / class->size;
-
error = 0; /* Success */
 
 cleanup:
@@ -1241,11 +1238,11 @@ static bool can_merge(struct size_class *prev, int 
size, int pages_per_zspage)
return true;
 }
 
-static bool zspage_full(struct page *first_page)
+static bool zspage_full(struct size_class *class, struct page *first_page)
 {
VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
 
-   return first_page->inuse == first_page->objects;
+   return first_page->inuse == class->objs_per_zspage;
 }
 
 unsigned long zs_get_total_pages(struct zs_pool *pool)
@@ -1631,7 +1628,7 @@ static int migrate_zspage(struct zs_pool *pool, struct 
size_class *class,
}
 
/* Stop if there is no more space */
-   if (zspage_full(d_page)) {
+   if (zspage_full(class, d_page)) {
unpin_tag(handle);
ret = -ENOMEM;
break;
@@ -1690,7 +1687,7 @@ static enum fullness_group putback_zspage(struct zs_pool 
*pool,
 {
enum fullness_group fullness;
 
-   fullness = get_fullness_group(first_page);
+   fullness = get_fullness_group(class, first_page);
insert_zspage(class, fullness, first_page);
set_zspage_mapping(first_page, class->index, fullness);
 
@@ -1939,8 +1936,9 @@ struct zs_pool *zs_create_pool(const char *name)
class->size = size;
class->index = i;
class->pages_per_zspage = pages_per_zspage;
-   if (pages_per_zspage == 1 &&
-   get_maxobj_per_zspage(size, pages_per_zspage) == 1)
+   class->objs_per_zspage = class->pages_per_zspage *
+   PAGE_SIZE / class->size;
+   if (pages_per_zspage == 1 && class->objs_per_zspage == 1)
class->huge = true;
spin_lock_init(>lock);
pool->size_class[i] = class;
-- 
1.9.1