Messages in this thread | | | Subject | Re: [PATCH v1 09/19] zsmalloc: keep max_object in size_class | From | xuyiping <> | Date | Sat, 12 Mar 2016 09:44:48 +0800 |
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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 <minchan@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;
>
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