Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751910Ab1CQHHK (ORCPT ); Thu, 17 Mar 2011 03:07:10 -0400 Received: from science.horizon.com ([71.41.210.146]:25529 "HELO science.horizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751288Ab1CQHHH (ORCPT ); Thu, 17 Mar 2011 03:07:07 -0400 Date: 17 Mar 2011 03:07:05 -0400 Message-ID: <20110317070705.15100.qmail@science.horizon.com> From: "George Spelvin" To: linux@horizon.com, penberg@kernel.org Subject: Re: [PATCH 5/8] mm/slub: Factor out some common code. Cc: herbert@gondor.hengli.com.au, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mpm@selenic.com, penberg@cs.helsinki.fi, rientjes@google.com In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9959 Lines: 263 > I certainly don't but I'd still like to ask you to change it to > 'unsigned long'. That's a Linux kernel idiom and we're not going to > change the whole kernel. Damn, and I just prepared the following patch. Should I, instead, do --- a/include/linux/slab_def.h +++ b/include/linux/slab_def.h @@ -62,5 +62,5 @@ struct kmem_cache { /* 3) touched by every alloc & free from the backend */ - unsigned int flags; /* constant flags */ + unsigned long flags; /* constant flags */ unsigned int num; /* # of objs per slab */ ... because the original slab code uses an unsigned int. To fix it the other way (for SLAB_ flags only) is a patch like this: >From 217645dfbb1fd42a451ae27aa1ea2c503ff31ef1 Mon Sep 17 00:00:00 2001 From: George Spelvin Date: Wed, 16 Mar 2011 22:36:50 -0400 Subject: [PATCH 01/11] mm: Make SLAB_* flags consistently 32-bit unsigned int. The type of "unsigned long" is silly for a portable flags field, because you can't portably use more than 32 bits, but it takes 64 bits on 64-bit processors. And 32-bit manipulations are never slower than 64-bit ones. Also, include/slab_def.h has always used an "unsigned int" flags field. This just updates the other implementations to do the same. (EXCEPTION: SLOB structure must match "struct page".) Signed-off-by: George Spelvin --- include/linux/slab.h | 38 +++++++++++++++++++------------------- include/linux/slub_def.h | 2 +- mm/slab.c | 2 +- mm/slob.c | 5 ++--- mm/slub.c | 22 +++++++++++----------- 5 files changed, 34 insertions(+), 35 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index fa90866..0ff4221 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -16,13 +16,13 @@ * Flags to pass to kmem_cache_create(). * The ones marked DEBUG are only valid if CONFIG_SLAB_DEBUG is set. */ -#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */ -#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */ -#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */ -#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */ -#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */ -#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */ -#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */ +#define SLAB_DEBUG_FREE 0x00000100U /* DEBUG: Perform (expensive) checks on free */ +#define SLAB_RED_ZONE 0x00000400U /* DEBUG: Red zone objs in a cache */ +#define SLAB_POISON 0x00000800U /* DEBUG: Poison objects */ +#define SLAB_HWCACHE_ALIGN 0x00002000U /* Align objs on cache lines */ +#define SLAB_CACHE_DMA 0x00004000U /* Use GFP_DMA memory */ +#define SLAB_STORE_USER 0x00010000U /* DEBUG: Store the last owner for bug hunting */ +#define SLAB_PANIC 0x00040000U /* Panic if kmem_cache_create() fails */ /* * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS! * @@ -51,33 +51,33 @@ * * See also the comment on struct slab_rcu in mm/slab.c. */ -#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */ -#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */ -#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */ +#define SLAB_DESTROY_BY_RCU 0x00080000U /* Defer freeing slabs to RCU */ +#define SLAB_MEM_SPREAD 0x00100000U /* Spread some memory over cpuset */ +#define SLAB_TRACE 0x00200000U /* Trace allocations and frees */ /* Flag to prevent checks on free */ #ifdef CONFIG_DEBUG_OBJECTS -# define SLAB_DEBUG_OBJECTS 0x00400000UL +# define SLAB_DEBUG_OBJECTS 0x00400000U #else -# define SLAB_DEBUG_OBJECTS 0x00000000UL +# define SLAB_DEBUG_OBJECTS 0x00000000U #endif -#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */ +#define SLAB_NOLEAKTRACE 0x00800000U /* Avoid kmemleak tracing */ /* Don't track use of uninitialized memory */ #ifdef CONFIG_KMEMCHECK -# define SLAB_NOTRACK 0x01000000UL +# define SLAB_NOTRACK 0x01000000U #else -# define SLAB_NOTRACK 0x00000000UL +# define SLAB_NOTRACK 0x00000000U #endif #ifdef CONFIG_FAILSLAB -# define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */ +# define SLAB_FAILSLAB 0x02000000U /* Fault injection mark */ #else -# define SLAB_FAILSLAB 0x00000000UL +# define SLAB_FAILSLAB 0x00000000U #endif /* The following flags affect the page allocator grouping pages by mobility */ -#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ +#define SLAB_RECLAIM_ACCOUNT 0x00020000U /* Objects are reclaimable */ #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ /* * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests. @@ -99,7 +99,7 @@ void __init kmem_cache_init(void); int slab_is_available(void); struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, - unsigned long, + unsigned int, void (*)(void *)); void kmem_cache_destroy(struct kmem_cache *); int kmem_cache_shrink(struct kmem_cache *); diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 8b6e8ae..5ed8408 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -69,7 +69,7 @@ struct kmem_cache_order_objects { struct kmem_cache { struct kmem_cache_cpu __percpu *cpu_slab; /* Used for retriving partial slabs etc */ - unsigned long flags; + unsigned int flags; int size; /* The size of an object including meta data */ int objsize; /* The size of an object without meta data */ int offset; /* Free pointer offset. */ diff --git a/mm/slab.c b/mm/slab.c index 37961d1..40e71b2 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2164,7 +2164,7 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp) */ struct kmem_cache * kmem_cache_create (const char *name, size_t size, size_t align, - unsigned long flags, void (*ctor)(void *)) + unsigned int flags, void (*ctor)(void *)) { size_t left_over, slab_size, ralign; struct kmem_cache *cachep = NULL, *pc; diff --git a/mm/slob.c b/mm/slob.c index 3588eaa..7745256 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -558,14 +558,13 @@ size_t ksize(const void *block) EXPORT_SYMBOL(ksize); struct kmem_cache { - unsigned int size, align; - unsigned long flags; + unsigned int size, align, flags; const char *name; void (*ctor)(void *); }; struct kmem_cache *kmem_cache_create(const char *name, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *)) + size_t align, unsigned int flags, void (*ctor)(void *)) { struct kmem_cache *c; diff --git a/mm/slub.c b/mm/slub.c index e15aa7f..ab36cbe 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1046,8 +1046,8 @@ out: __setup("slub_debug", setup_slub_debug); -static unsigned long kmem_cache_flags(unsigned long objsize, - unsigned long flags, const char *name, +static unsigned int kmem_cache_flags(unsigned long objsize, + unsigned int flags, const char *name, void (*ctor)(void *)) { /* @@ -1074,8 +1074,8 @@ static inline int slab_pad_check(struct kmem_cache *s, struct page *page) static inline int check_object(struct kmem_cache *s, struct page *page, void *object, u8 val) { return 1; } static inline void add_full(struct kmem_cache_node *n, struct page *page) {} -static inline unsigned long kmem_cache_flags(unsigned long objsize, - unsigned long flags, const char *name, +static inline unsigned int kmem_cache_flags(unsigned long objsize, + unsigned int flags, const char *name, void (*ctor)(void *)) { return flags; @@ -2069,7 +2069,7 @@ static inline int calculate_order(int size) /* * Figure out what the alignment of the objects will be. */ -static unsigned long calculate_alignment(unsigned long flags, +static unsigned long calculate_alignment(unsigned int flags, unsigned long align, unsigned long size) { /* @@ -2220,7 +2220,7 @@ static void set_min_partial(struct kmem_cache *s, unsigned long min) */ static int calculate_sizes(struct kmem_cache *s, int forced_order) { - unsigned long flags = s->flags; + unsigned int flags = s->flags; unsigned long size = s->objsize; unsigned long align = s->align; int order; @@ -2340,7 +2340,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) static int kmem_cache_open(struct kmem_cache *s, const char *name, size_t size, - size_t align, unsigned long flags, + size_t align, unsigned int flags, void (*ctor)(void *)) { memset(s, 0, kmem_size); @@ -2384,7 +2384,7 @@ static int kmem_cache_open(struct kmem_cache *s, error: if (flags & SLAB_PANIC) panic("Cannot create slab %s size=%lu realsize=%u " - "order=%u offset=%u flags=%lx\n", + "order=%u offset=%u flags=%x\n", s->name, (unsigned long)size, s->size, oo_order(s->oo), s->offset, flags); return 0; @@ -3160,7 +3160,7 @@ static int slab_unmergeable(struct kmem_cache *s) } static struct kmem_cache *find_mergeable(size_t size, - size_t align, unsigned long flags, const char *name, + size_t align, unsigned int flags, const char *name, void (*ctor)(void *)) { struct kmem_cache *s; @@ -3201,7 +3201,7 @@ static struct kmem_cache *find_mergeable(size_t size, } struct kmem_cache *kmem_cache_create(const char *name, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *)) + size_t align, unsigned int flags, void (*ctor)(void *)) { struct kmem_cache *s; char *n; @@ -3760,7 +3760,7 @@ enum slab_stat_type { #define SO_TOTAL (1 << SL_TOTAL) static ssize_t show_slab_objects(struct kmem_cache *s, - char *buf, unsigned long flags) + char *buf, unsigned int flags) { unsigned long total = 0; 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