diff options
| author | Hyeonggon Yoo <42.hyeyoo@gmail.com> | 2022-08-17 19:18:19 +0900 |
|---|---|---|
| committer | Vlastimil Babka <vbabka@suse.cz> | 2022-08-24 16:11:41 +0200 |
| commit | d6a71648dbc0ca5520cba16a8fdce8d37ae74218 (patch) | |
| tree | b15d1f620d72682e4c169024d798307f5792a62d /include/linux/slab.h | |
| parent | c4cab557521a73bd803e5c6f613b4e00bd3c4662 (diff) | |
mm/slab: kmalloc: pass requests larger than order-1 page to page allocator
There is not much benefit for serving large objects in kmalloc().
Let's pass large requests to page allocator like SLUB for better
maintenance of common code.
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'include/linux/slab.h')
| -rw-r--r-- | include/linux/slab.h | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index fd2e129fc813..4ee5b2fed164 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -243,27 +243,17 @@ static inline unsigned int arch_slab_minalign(void) #ifdef CONFIG_SLAB /* - * The largest kmalloc size supported by the SLAB allocators is - * 32 megabyte (2^25) or the maximum allocatable page order if that is - * less than 32 MB. - * - * WARNING: Its not easy to increase this value since the allocators have - * to do various tricks to work around compiler limitations in order to - * ensure proper constant folding. + * SLAB and 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 ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \ - (MAX_ORDER + PAGE_SHIFT - 1) : 25) -#define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH +#define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1) +#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT - 1) #ifndef KMALLOC_SHIFT_LOW #define KMALLOC_SHIFT_LOW 5 #endif #endif #ifdef CONFIG_SLUB -/* - * 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 - 1) #ifndef KMALLOC_SHIFT_LOW @@ -415,10 +405,6 @@ static __always_inline unsigned int __kmalloc_index(size_t size, if (size <= 512 * 1024) return 19; if (size <= 1024 * 1024) return 20; if (size <= 2 * 1024 * 1024) return 21; - if (size <= 4 * 1024 * 1024) return 22; - if (size <= 8 * 1024 * 1024) return 23; - if (size <= 16 * 1024 * 1024) return 24; - if (size <= 32 * 1024 * 1024) return 25; if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); @@ -428,6 +414,7 @@ static __always_inline unsigned int __kmalloc_index(size_t size, /* Will never be reached. Needed because the compiler may complain */ return -1; } +static_assert(PAGE_SHIFT <= 20); #define kmalloc_index(s) __kmalloc_index(s, true) #endif /* !CONFIG_SLOB */ |