On Sat, Mar 12, 2016 at 09:44:48AM +0800, xuyiping wrote:
>
>
> On 2016/3/11 15:30, Minchan Kim wrote:
> >Every zspage in a size_class has same number of max objects so
> >we could move it to a size_class.
> >
> >Signed-off-by: Minchan Kim <minc...@kernel.org>
> >---
> > mm/zsmalloc.c | 29 ++++++++++++++---------------
> > 1 file changed, 14 insertions(+), 15 deletions(-)
> >
> >diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> >index b4fb11831acb..ca663c82c1fc 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;
> >@@ -622,21 +621,22 @@ 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;
> >@@ -723,7 +723,7 @@ static enum fullness_group fix_fullness_group(struct
> >size_class *class,
> > enum fullness_group currfg, newfg;
> >
> > get_zspage_mapping(first_page, &class_idx, &currfg);
> >- newfg = get_fullness_group(first_page);
> >+ newfg = get_fullness_group(class, first_page);
> > if (newfg == currfg)
> > goto out;
> >
> >@@ -1003,9 +1003,6 @@ 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:
> >@@ -1235,11 +1232,11 @@ 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)
> >@@ -1625,7 +1622,7 @@ 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;
> >@@ -1684,7 +1681,7 @@ 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);
> >
> >@@ -1933,6 +1930,8 @@ struct zs_pool *zs_create_pool(const char *name, gfp_t
> >flags)
> > class->size = size;
> > class->index = i;
> > class->pages_per_zspage = pages_per_zspage;
> >+ class->objs_per_zspage = class->pages_per_zspage *
> >+ PAGE_SIZE / class->size;
> > if (pages_per_zspage == 1 &&
> > get_maxobj_per_zspage(size, pages_per_zspage) == 1)
> > class->huge = true;
>
> computes the "objs_per_zspage" twice here.
>
> class->objs_per_zspage = get_maxobj_per_zspage(size,
> pages_per_zspage);
> if (pages_per_zspage == 1 && class->objs_per_zspage ==1)
> class->huge = true;
Yeb. I will do.
Thanks.
