From 692ae74aaf226a557d88d5412a1764c09e63a193 Mon Sep 17 00:00:00 2001 From: Byongho Lee Date: Wed, 31 Jan 2018 16:15:36 -0800 Subject: [PATCH] mm/slab_common.c: make calculate_alignment() static calculate_alignment() function is only used inside slab_common.c. So make it static and let the compiler do more optimizations. After this patch there's a small improvement in text and data size. $ gcc --version gcc (GCC) 7.2.1 20171128 Before: text data bss dec hex filename 9890457 3828702 1212364 14931523 e3d643 vmlinux After: text data bss dec hex filename 9890437 3828670 1212364 14931471 e3d60f vmlinux Also I fixed a style problem reported by checkpatch. WARNING: Missing a blank line after declarations #53: FILE: mm/slab_common.c:286: + unsigned long ralign = cache_line_size(); + while (size <= ralign / 2) Link: http://lkml.kernel.org/r/20171210080132.406-1-bhlee.kernel@gmail.com Signed-off-by: Byongho Lee Acked-by: Michal Hocko Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.h | 3 --- mm/slab_common.c | 56 +++++++++++++++++++++++++++++--------------------------- 2 files changed, 29 insertions(+), 30 deletions(-) diff --git a/mm/slab.h b/mm/slab.h index ad657ff..e8e2095 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -78,9 +78,6 @@ extern const struct kmalloc_info_struct { unsigned long size; } kmalloc_info[]; -unsigned long calculate_alignment(slab_flags_t flags, - unsigned long align, unsigned long size); - #ifndef CONFIG_SLOB /* Kmalloc array related functions */ void setup_kmalloc_cache_index_table(void); diff --git a/mm/slab_common.c b/mm/slab_common.c index c8cb367..deeddf9 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -268,6 +268,35 @@ static inline void memcg_unlink_cache(struct kmem_cache *s) #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ /* + * Figure out what the alignment of the objects will be given a set of + * flags, a user specified alignment and the size of the objects. + */ +static unsigned long calculate_alignment(unsigned long flags, + unsigned long align, unsigned long size) +{ + /* + * If the user wants hardware cache aligned objects then follow that + * suggestion if the object is sufficiently large. + * + * The hardware cache alignment cannot override the specified + * alignment though. If that is greater then use it. + */ + if (flags & SLAB_HWCACHE_ALIGN) { + unsigned long ralign; + + ralign = cache_line_size(); + while (size <= ralign / 2) + ralign /= 2; + align = max(align, ralign); + } + + if (align < ARCH_SLAB_MINALIGN) + align = ARCH_SLAB_MINALIGN; + + return ALIGN(align, sizeof(void *)); +} + +/* * Find a mergeable slab cache */ int slab_unmergeable(struct kmem_cache *s) @@ -337,33 +366,6 @@ struct kmem_cache *find_mergeable(size_t size, size_t align, return NULL; } -/* - * Figure out what the alignment of the objects will be given a set of - * flags, a user specified alignment and the size of the objects. - */ -unsigned long calculate_alignment(slab_flags_t flags, - unsigned long align, unsigned long size) -{ - /* - * If the user wants hardware cache aligned objects then follow that - * suggestion if the object is sufficiently large. - * - * The hardware cache alignment cannot override the specified - * alignment though. If that is greater then use it. - */ - if (flags & SLAB_HWCACHE_ALIGN) { - unsigned long ralign = cache_line_size(); - while (size <= ralign / 2) - ralign /= 2; - align = max(align, ralign); - } - - if (align < ARCH_SLAB_MINALIGN) - align = ARCH_SLAB_MINALIGN; - - return ALIGN(align, sizeof(void *)); -} - static struct kmem_cache *create_cache(const char *name, size_t object_size, size_t size, size_t align, slab_flags_t flags, void (*ctor)(void *), -- 2.7.4