From e1168c2cc4a5a5e495a53e067a6be6b4f29abfe0 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 22 Nov 2013 18:14:38 -0800 Subject: slab.h: remove duplicate kmalloc declaration and fix kernel-doc warnings Fix kernel-doc warning for duplicate definition of 'kmalloc': Documentation/DocBook/kernel-api.xml:9483: element refentry: validity error : ID API-kmalloc already defined Also combine the kernel-doc info from the 2 kmalloc definitions into one block and remove the "see kcalloc" comment since kmalloc now contains the @flags info. Signed-off-by: Randy Dunlap Acked-by: Christoph Lameter Signed-off-by: Pekka Enberg --- include/linux/slab.h | 102 +++++++++++++++++++++++---------------------------- 1 file changed, 46 insertions(+), 56 deletions(-) (limited to 'include/linux/slab.h') diff --git a/include/linux/slab.h b/include/linux/slab.h index c2bba24..1e2f4fe 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -388,10 +388,55 @@ static __always_inline void *kmalloc_large(size_t size, gfp_t flags) /** * kmalloc - allocate memory * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate (see kcalloc). + * @flags: the type of memory to allocate. * * kmalloc is the normal method of allocating memory * for objects smaller than page size in the kernel. + * + * The @flags argument may be one of: + * + * %GFP_USER - Allocate memory on behalf of user. May sleep. + * + * %GFP_KERNEL - Allocate normal kernel ram. May sleep. + * + * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. + * For example, use this inside interrupt handlers. + * + * %GFP_HIGHUSER - Allocate pages from high memory. + * + * %GFP_NOIO - Do not do any I/O at all while trying to get memory. + * + * %GFP_NOFS - Do not make any fs calls while trying to get memory. + * + * %GFP_NOWAIT - Allocation will not sleep. + * + * %GFP_THISNODE - Allocate node-local memory only. + * + * %GFP_DMA - Allocation suitable for DMA. + * Should only be used for kmalloc() caches. Otherwise, use a + * slab created with SLAB_DMA. + * + * Also it is possible to set different flags by OR'ing + * in one or more of the following additional @flags: + * + * %__GFP_COLD - Request cache-cold pages instead of + * trying to return cache-warm pages. + * + * %__GFP_HIGH - This allocation has high priority and may use emergency pools. + * + * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail + * (think twice before using). + * + * %__GFP_NORETRY - If memory is not immediately available, + * then give up at once. + * + * %__GFP_NOWARN - If allocation fails, don't issue any warnings. + * + * %__GFP_REPEAT - If allocation fails initially, try once more before failing. + * + * There are other flags available as well, but these are not intended + * for general use, and so are not documented here. For a full list of + * potential flags, always refer to linux/gfp.h. */ static __always_inline void *kmalloc(size_t size, gfp_t flags) { @@ -502,61 +547,6 @@ int cache_show(struct kmem_cache *s, struct seq_file *m); void print_slabinfo_header(struct seq_file *m); /** - * kmalloc - allocate memory - * @size: how many bytes of memory are required. - * @flags: the type of memory to allocate. - * - * The @flags argument may be one of: - * - * %GFP_USER - Allocate memory on behalf of user. May sleep. - * - * %GFP_KERNEL - Allocate normal kernel ram. May sleep. - * - * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools. - * For example, use this inside interrupt handlers. - * - * %GFP_HIGHUSER - Allocate pages from high memory. - * - * %GFP_NOIO - Do not do any I/O at all while trying to get memory. - * - * %GFP_NOFS - Do not make any fs calls while trying to get memory. - * - * %GFP_NOWAIT - Allocation will not sleep. - * - * %GFP_THISNODE - Allocate node-local memory only. - * - * %GFP_DMA - Allocation suitable for DMA. - * Should only be used for kmalloc() caches. Otherwise, use a - * slab created with SLAB_DMA. - * - * Also it is possible to set different flags by OR'ing - * in one or more of the following additional @flags: - * - * %__GFP_COLD - Request cache-cold pages instead of - * trying to return cache-warm pages. - * - * %__GFP_HIGH - This allocation has high priority and may use emergency pools. - * - * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail - * (think twice before using). - * - * %__GFP_NORETRY - If memory is not immediately available, - * then give up at once. - * - * %__GFP_NOWARN - If allocation fails, don't issue any warnings. - * - * %__GFP_REPEAT - If allocation fails initially, try once more before failing. - * - * There are other flags available as well, but these are not intended - * for general use, and so are not documented here. For a full list of - * potential flags, always refer to linux/gfp.h. - * - * kmalloc is the normal method of allocating memory - * in the kernel. - */ -static __always_inline void *kmalloc(size_t size, gfp_t flags); - -/** * kmalloc_array - allocate memory for an array. * @n: number of elements. * @size: element size. -- cgit v1.1 From 433a91ff5fa19e3eb70b12f7056f234aebd09ac2 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Tue, 28 Jan 2014 14:24:50 -0800 Subject: mm: sl[uo]b: fix misleading comments On x86, SLUB creates and handles <=8192-byte allocations internally. It passes larger ones up to the allocator. Saying "up to order 2" is, at best, ambiguous. Is that order-1? Or (order-2 bytes)? Make it more clear. SLOB commits a similar sin. It *handles* page-size requests, but the comment says that it passes up "all page size and larger requests". SLOB also swaps around the order of the very-similarly-named KMALLOC_SHIFT_HIGH and KMALLOC_SHIFT_MAX #defines. Make it consistent with the order of the other two allocators. Cc: Matt Mackall Cc: Andrew Morton Acked-by: Christoph Lameter Acked-by: David Rientjes Signed-off-by: Dave Hansen Signed-off-by: Pekka Enberg --- include/linux/slab.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/slab.h') diff --git a/include/linux/slab.h b/include/linux/slab.h index 1e2f4fe..f76e956 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -205,8 +205,8 @@ struct kmem_cache { #ifdef CONFIG_SLUB /* - * SLUB allocates up to order 2 pages directly and otherwise - * passes the request to the page allocator. + * SLUB directly allocates requests fitting in to an order-1 page + * (PAGE_SIZE*2). Larger requests are passed to the page allocator. */ #define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) #define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT) @@ -217,12 +217,12 @@ struct kmem_cache { #ifdef CONFIG_SLOB /* - * SLOB passes all page size and larger requests to the page allocator. + * SLOB passes all requests larger than one page to the page allocator. * No kmalloc array is necessary since objects of different sizes can * be allocated from the same page. */ -#define KMALLOC_SHIFT_MAX 30 #define KMALLOC_SHIFT_HIGH PAGE_SHIFT +#define KMALLOC_SHIFT_MAX 30 #ifndef KMALLOC_SHIFT_LOW #define KMALLOC_SHIFT_LOW 3 #endif -- cgit v1.1