From bdb0af7ca8f0e9f4c03a9169a744b22890641b64 Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Tue, 26 Jul 2016 15:23:20 -0700 Subject: [PATCH] zsmalloc: factor page chain functionality out For page migration, we need to create page chain of zspage dynamically so this patch factors it out from alloc_zspage. Link: http://lkml.kernel.org/r/1464736881-24886-8-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 | 59 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 35 insertions(+), 24 deletions(-) diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 5da80961ff3e..07485a2e5b96 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -960,7 +960,8 @@ static void init_zspage(struct size_class *class, struct page *first_page) unsigned long off = 0; struct page *page = first_page; - VM_BUG_ON_PAGE(!is_first_page(first_page), first_page); + first_page->freelist = NULL; + set_zspage_inuse(first_page, 0); while (page) { struct page *next_page; @@ -996,15 +997,16 @@ static void init_zspage(struct size_class *class, struct page *first_page) page = next_page; off %= PAGE_SIZE; } + + set_freeobj(first_page, (unsigned long)location_to_obj(first_page, 0)); } -/* - * Allocate a zspage for the given size class - */ -static struct page *alloc_zspage(struct size_class *class, gfp_t flags) +static void create_page_chain(struct page *pages[], int nr_pages) { - int i, error; - struct page *first_page = NULL, *uninitialized_var(prev_page); + int i; + struct page *page; + struct page *prev_page = NULL; + struct page *first_page = NULL; /* * Allocate individual pages and link them together as: @@ -1017,20 +1019,14 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) * (i.e. no other sub-page has this flag set) and PG_private_2 to * identify the last page. */ - error = -ENOMEM; - for (i = 0; i < class->pages_per_zspage; i++) { - struct page *page; - - page = alloc_page(flags); - if (!page) - goto cleanup; + for (i = 0; i < nr_pages; i++) { + page = pages[i]; INIT_LIST_HEAD(&page->lru); - if (i == 0) { /* first page */ + if (i == 0) { SetPagePrivate(page); set_page_private(page, 0); first_page = page; - set_zspage_inuse(first_page, 0); } if (i == 1) set_page_private(first_page, (unsigned long)page); @@ -1038,22 +1034,37 @@ static struct page *alloc_zspage(struct size_class *class, gfp_t flags) set_page_private(page, (unsigned long)first_page); if (i >= 2) list_add(&page->lru, &prev_page->lru); - if (i == class->pages_per_zspage - 1) /* last page */ + if (i == nr_pages - 1) SetPagePrivate2(page); prev_page = page; } +} - init_zspage(class, first_page); +/* + * Allocate a zspage for the given size class + */ +static struct page *alloc_zspage(struct size_class *class, gfp_t flags) +{ + int i; + struct page *first_page = NULL; + struct page *pages[ZS_MAX_PAGES_PER_ZSPAGE]; - set_freeobj(first_page, (unsigned long)location_to_obj(first_page, 0)); - error = 0; /* Success */ + for (i = 0; i < class->pages_per_zspage; i++) { + struct page *page; -cleanup: - if (unlikely(error) && first_page) { - free_zspage(first_page); - first_page = NULL; + page = alloc_page(flags); + if (!page) { + while (--i >= 0) + __free_page(pages[i]); + return NULL; + } + pages[i] = page; } + create_page_chain(pages, class->pages_per_zspage); + first_page = pages[0]; + init_zspage(class, first_page); + return first_page; }