From 84097518d1ecd2330f9488e4c2d09953a3340e74 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 22 Mar 2006 00:08:34 -0800 Subject: [PATCH] [PATCH] mm: nommu use compound pages Now that compound page handling is properly fixed in the VM, move nommu over to using compound pages rather than rolling their own refcounting. nommu vm page refcounting is broken anyway, but there is no need to have divergent code in the core VM now, nor when it gets fixed. Signed-off-by: Nick Piggin Cc: David Howells (Needs testing, please). Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ramfs/file-nommu.c | 3 +-- include/linux/mm.h | 4 ---- mm/internal.h | 12 ------------ mm/nommu.c | 4 ++-- mm/page_alloc.c | 7 ------- mm/slab.c | 9 ++++++++- 6 files changed, 11 insertions(+), 28 deletions(-) diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c index 3f810acd0bf..b1ca234068f 100644 --- a/fs/ramfs/file-nommu.c +++ b/fs/ramfs/file-nommu.c @@ -87,8 +87,7 @@ static int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize) xpages = 1UL << order; npages = (newsize + PAGE_SIZE - 1) >> PAGE_SHIFT; - for (loop = 0; loop < npages; loop++) - set_page_count(pages + loop, 1); + split_page(pages, order); /* trim off any pages we don't actually require */ for (loop = npages; loop < xpages; loop++) diff --git a/include/linux/mm.h b/include/linux/mm.h index 9b3cdfc8046..3d84b7a35e0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -327,11 +327,7 @@ static inline void get_page(struct page *page) void put_page(struct page *page); -#ifdef CONFIG_MMU void split_page(struct page *page, unsigned int order); -#else -static inline void split_page(struct page *page, unsigned int order) {} -#endif /* * Multiple processes may "see" the same page. E.g. for untouched diff --git a/mm/internal.h b/mm/internal.h index e3042db2a2d..7bb33977981 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -15,19 +15,7 @@ static inline void set_page_refs(struct page *page, int order) { -#ifdef CONFIG_MMU set_page_count(page, 1); -#else - int i; - - /* - * We need to reference all the pages for this order, otherwise if - * anyone accesses one of the pages with (get/put) it will be freed. - * - eg: access_process_vm() - */ - for (i = 0; i < (1 << order); i++) - set_page_count(page + i, 1); -#endif /* CONFIG_MMU */ } static inline void __put_page(struct page *page) diff --git a/mm/nommu.c b/mm/nommu.c index 4951f4786f2..db45efac17c 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -159,7 +159,7 @@ void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) /* * kmalloc doesn't like __GFP_HIGHMEM for some reason */ - return kmalloc(size, gfp_mask & ~__GFP_HIGHMEM); + return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); } struct page * vmalloc_to_page(void *addr) @@ -623,7 +623,7 @@ static int do_mmap_private(struct vm_area_struct *vma, unsigned long len) * - note that this may not return a page-aligned address if the object * we're allocating is smaller than a page */ - base = kmalloc(len, GFP_KERNEL); + base = kmalloc(len, GFP_KERNEL|__GFP_COMP); if (!base) goto enomem; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7aa0181287e..e197818a7cf 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -422,11 +422,6 @@ static void __free_pages_ok(struct page *page, unsigned int order) mutex_debug_check_no_locks_freed(page_address(page), PAGE_SIZE<lru.next; } @@ -600,6 +602,8 @@ static inline void page_set_slab(struct page *page, struct slab *slab) static inline struct slab *page_get_slab(struct page *page) { + if (unlikely(PageCompound(page))) + page = (struct page *)page_private(page); return (struct slab *)page->lru.prev; } @@ -2412,8 +2416,11 @@ static void set_slab_attr(struct kmem_cache *cachep, struct slab *slabp, struct page *page; /* Nasty!!!!!! I hope this is OK. */ - i = 1 << cachep->gfporder; page = virt_to_page(objp); + + i = 1; + if (likely(!PageCompound(page))) + i <<= cachep->gfporder; do { page_set_cache(page, cachep); page_set_slab(page, slabp); -- 2.20.1