Messages in this thread Patch in this message | | | Subject | Re: New (now current development process) | From | Roland Dreier <> | Date | Tue, 01 Nov 2005 21:01:01 -0800 |
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> And a lot of it is us just being bloated. Argh.
Perhaps it's time to dust this patch off:
Reduce kernel text by moving many uses of GFP_KERNEL out of line, by creating __kmem_cache_alloc_gfp_kernel(), __kmalloc_gfp_kernel() and __kzalloc_gfp_kernel() wrapper functions. Then kmem_cache_alloc(), kmalloc() and kzalloc() can be inline functions that just call their _gfp_kernel version if their flags parameter is a compile-time constant and is GFP_KERNEL, and call their ordinary version otherwise.
On an x86_64 allnoconfig kernel, I see the following sizes:
text data bss dec hex filename 795683 197356 116384 1109423 10edaf vmlinux-before 794894 197420 116384 1108698 10eada vmlinux-after
for a net savings of 789 bytes of text. More realistic configs will save even more. With my usual config, the patched kernel boots and runs fine.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/linux/slab.h b/include/linux/slab.h index 09b9aa6..618331d 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -61,7 +61,8 @@ extern kmem_cache_t *kmem_cache_create(c void (*)(void *, kmem_cache_t *, unsigned long)); extern int kmem_cache_destroy(kmem_cache_t *); extern int kmem_cache_shrink(kmem_cache_t *); -extern void *kmem_cache_alloc(kmem_cache_t *, gfp_t); +extern void *__kmem_cache_alloc(kmem_cache_t *, gfp_t); +extern void *__kmem_cache_alloc_gfp_kernel(kmem_cache_t *); extern void kmem_cache_free(kmem_cache_t *, void *); extern unsigned int kmem_cache_size(kmem_cache_t *); extern const char *kmem_cache_name(kmem_cache_t *); @@ -75,6 +76,15 @@ struct cache_sizes { }; extern struct cache_sizes malloc_sizes[]; extern void *__kmalloc(size_t, gfp_t); +extern void *__kmalloc_gfp_kernel(size_t); + +static inline void *kmem_cache_alloc(kmem_cache_t *cache, gfp_t flags) +{ + if (__builtin_constant_p(flags) && flags == GFP_KERNEL) + return __kmem_cache_alloc_gfp_kernel(cache); + + return __kmem_cache_alloc(cache, flags); +} static inline void *kmalloc(size_t size, gfp_t flags) { @@ -96,10 +106,22 @@ found: malloc_sizes[i].cs_dmacachep : malloc_sizes[i].cs_cachep, flags); } + + if (__builtin_constant_p(flags) && flags == GFP_KERNEL) + return __kmalloc_gfp_kernel(size); return __kmalloc(size, flags); } -extern void *kzalloc(size_t, gfp_t); +extern void *__kzalloc(size_t, gfp_t); +extern void *__kzalloc_gfp_kernel(size_t); + +static inline void *kzalloc(size_t size, gfp_t flags) +{ + if (__builtin_constant_p(flags) && flags == GFP_KERNEL) + return __kzalloc_gfp_kernel(size); + + return __kzalloc(size, flags); +} /** * kcalloc - allocate memory for an array. The memory is set to zero. diff --git a/mm/slab.c b/mm/slab.c index 22bfb0b..2971e1c 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2788,11 +2788,17 @@ static inline void __cache_free(kmem_cac * Allocate an object from this cache. The flags are only relevant * if the cache has no available objects. */ -void *kmem_cache_alloc(kmem_cache_t *cachep, gfp_t flags) +void *__kmem_cache_alloc(kmem_cache_t *cachep, gfp_t flags) { return __cache_alloc(cachep, flags); } -EXPORT_SYMBOL(kmem_cache_alloc); +EXPORT_SYMBOL(__kmem_cache_alloc); + +void *__kmem_cache_alloc_gfp_kernel(kmem_cache_t *cachep) +{ + return __cache_alloc(cachep, GFP_KERNEL); +} +EXPORT_SYMBOL(__kmem_cache_alloc_gfp_kernel); /** * kmem_ptr_validate - check if an untrusted pointer might @@ -2925,6 +2931,12 @@ void *__kmalloc(size_t size, gfp_t flags } EXPORT_SYMBOL(__kmalloc); +void *__kmalloc_gfp_kernel(size_t size) +{ + return __kmalloc(size, GFP_KERNEL); +} +EXPORT_SYMBOL(__kmalloc_gfp_kernel); + #ifdef CONFIG_SMP /** * __alloc_percpu - allocate one copy of the object for every present @@ -2998,14 +3010,20 @@ EXPORT_SYMBOL(kmem_cache_free); * @size: how many bytes of memory are required. * @flags: the type of memory to allocate. */ -void *kzalloc(size_t size, gfp_t flags) +void *__kzalloc(size_t size, gfp_t flags) { void *ret = kmalloc(size, flags); if (ret) memset(ret, 0, size); return ret; } -EXPORT_SYMBOL(kzalloc); +EXPORT_SYMBOL(__kzalloc); + +void *__kzalloc_gfp_kernel(size_t size) +{ + return __kzalloc(size, GFP_KERNEL); +} +EXPORT_SYMBOL(__kzalloc_gfp_kernel); /** * kfree - free previously allocated memory - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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