From 4f42047bbde059823fe70381387257a9e3bd229c Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 26 Jul 2016 15:23:17 -0700 Subject: [PATCH] zsmalloc: use accessor Upcoming patch will change how to encode zspage meta so for easy review, this patch wraps code to access metadata as accessor. Link: http://lkml.kernel.org/r/1464736881-24886-7-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim Reviewed-by: Sergey Senozhatsky Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/zsmalloc.c | 82 +++++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 60 insertions(+), 22 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 39f29ae..5da8096 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -268,10 +268,14 @@ struct zs_pool { * A zspage's class index and fullness group * are encoded in its (first)page->mapping */ -#define CLASS_IDX_BITS 28 #define FULLNESS_BITS 4 -#define CLASS_IDX_MASK ((1 << CLASS_IDX_BITS) - 1) -#define FULLNESS_MASK ((1 << FULLNESS_BITS) - 1) +#define CLASS_BITS 28 + +#define FULLNESS_SHIFT 0 +#define CLASS_SHIFT (FULLNESS_SHIFT + FULLNESS_BITS) + +#define FULLNESS_MASK ((1UL << FULLNESS_BITS) - 1) +#define CLASS_MASK ((1UL << CLASS_BITS) - 1) struct mapping_area { #ifdef CONFIG_PGTABLE_MAPPING @@ -418,6 +422,41 @@ static int is_last_page(struct page *page) return PagePrivate2(page); } +static inline int get_zspage_inuse(struct page *first_page) +{ + return first_page->inuse; +} + +static inline void set_zspage_inuse(struct page *first_page, int val) +{ + first_page->inuse = val; +} + +static inline void mod_zspage_inuse(struct page *first_page, int val) +{ + first_page->inuse += val; +} + +static inline int get_first_obj_offset(struct page *page) +{ + return page->index; +} + +static inline void set_first_obj_offset(struct page *page, int offset) +{ + page->index = offset; +} + +static inline unsigned long get_freeobj(struct page *first_page) +{ + return (unsigned long)first_page->freelist; +} + +static inline void set_freeobj(struct page *first_page, unsigned long obj) +{ + first_page->freelist = (void *)obj; +} + static void get_zspage_mapping(struct page *first_page, unsigned int *class_idx, enum fullness_group *fullness) @@ -426,8 +465,8 @@ static void get_zspage_mapping(struct page *first_page, VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); m = (unsigned long)first_page->mapping; - *fullness = m & FULLNESS_MASK; - *class_idx = (m >> FULLNESS_BITS) & CLASS_IDX_MASK; + *fullness = (m >> FULLNESS_SHIFT) & FULLNESS_MASK; + *class_idx = (m >> CLASS_SHIFT) & CLASS_MASK; } static void set_zspage_mapping(struct page *first_page, @@ -437,8 +476,7 @@ static void set_zspage_mapping(struct page *first_page, unsigned long m; VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); - m = ((class_idx & CLASS_IDX_MASK) << FULLNESS_BITS) | - (fullness & FULLNESS_MASK); + m = (class_idx << CLASS_SHIFT) | (fullness << FULLNESS_SHIFT); first_page->mapping = (struct address_space *)m; } @@ -638,7 +676,7 @@ static enum fullness_group get_fullness_group(struct size_class *class, VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); - inuse = first_page->inuse; + inuse = get_zspage_inuse(first_page); objs_per_zspage = class->objs_per_zspage; if (inuse == 0) @@ -684,7 +722,7 @@ static void insert_zspage(struct size_class *class, * empty/full. Put pages with higher ->inuse first. */ list_add_tail(&first_page->lru, &(*head)->lru); - if (first_page->inuse >= (*head)->inuse) + if (get_zspage_inuse(first_page) >= get_zspage_inuse(*head)) *head = first_page; } @@ -861,7 +899,7 @@ static unsigned long obj_idx_to_offset(struct page *page, unsigned long off = 0; if (!is_first_page(page)) - off = page->index; + off = get_first_obj_offset(page); return off + obj_idx * class_size; } @@ -896,7 +934,7 @@ static void free_zspage(struct page *first_page) struct page *nextp, *tmp, *head_extra; VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); - VM_BUG_ON_PAGE(first_page->inuse, first_page); + VM_BUG_ON_PAGE(get_zspage_inuse(first_page), first_page); head_extra = (struct page *)page_private(first_page); @@ -937,7 +975,7 @@ static void init_zspage(struct size_class *class, struct page *first_page) * head of corresponding zspage's freelist. */ if (page != first_page) - page->index = off; + set_first_obj_offset(page, off); vaddr = kmap_atomic(page); link = (struct link_free *)vaddr + off / sizeof(*link); @@ -992,7 +1030,7 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) SetPagePrivate(page); set_page_private(page, 0); first_page = page; - first_page->inuse = 0; + set_zspage_inuse(first_page, 0); } if (i == 1) set_page_private(first_page, (unsigned long)page); @@ -1007,7 +1045,7 @@ 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); + set_freeobj(first_page, (unsigned long)location_to_obj(first_page, 0)); error = 0; /* Success */ cleanup: @@ -1239,7 +1277,7 @@ 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 == class->objs_per_zspage; + return get_zspage_inuse(first_page) == class->objs_per_zspage; } unsigned long zs_get_total_pages(struct zs_pool *pool) @@ -1358,13 +1396,13 @@ static unsigned long obj_malloc(struct size_class *class, void *vaddr; handle |= OBJ_ALLOCATED_TAG; - obj = (unsigned long)first_page->freelist; + obj = get_freeobj(first_page); obj_to_location(obj, &m_page, &m_objidx); m_offset = obj_idx_to_offset(m_page, m_objidx, class->size); vaddr = kmap_atomic(m_page); link = (struct link_free *)vaddr + m_offset / sizeof(*link); - first_page->freelist = link->next; + set_freeobj(first_page, (unsigned long)link->next); if (!class->huge) /* record handle in the header of allocated chunk */ link->handle = handle; @@ -1372,7 +1410,7 @@ static unsigned long obj_malloc(struct size_class *class, /* record handle in first_page->private */ set_page_private(first_page, handle); kunmap_atomic(vaddr); - first_page->inuse++; + mod_zspage_inuse(first_page, 1); zs_stat_inc(class, OBJ_USED, 1); return obj; @@ -1452,12 +1490,12 @@ static void obj_free(struct size_class *class, unsigned long obj) /* Insert this object in containing zspage's freelist */ link = (struct link_free *)(vaddr + f_offset); - link->next = first_page->freelist; + link->next = (void *)get_freeobj(first_page); if (class->huge) set_page_private(first_page, 0); kunmap_atomic(vaddr); - first_page->freelist = (void *)obj; - first_page->inuse--; + set_freeobj(first_page, obj); + mod_zspage_inuse(first_page, -1); zs_stat_dec(class, OBJ_USED, 1); } @@ -1573,7 +1611,7 @@ static unsigned long find_alloced_obj(struct size_class *class, void *addr = kmap_atomic(page); if (!is_first_page(page)) - offset = page->index; + offset = get_first_obj_offset(page); offset += class->size * index; while (offset < PAGE_SIZE) { -- 2.7.4