diff options
Diffstat (limited to 'include/linux/slab.h')
| -rw-r--r-- | include/linux/slab.h | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index 0c97d788762c..bc9ab3a5a017 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -346,8 +346,14 @@ static __always_inline enum kmalloc_cache_type kmalloc_type(gfp_t flags) * 1 = 65 .. 96 bytes * 2 = 129 .. 192 bytes * n = 2^(n-1)+1 .. 2^n + * + * Note: __kmalloc_index() is compile-time optimized, and not runtime optimized; + * typical usage is via kmalloc_index() and therefore evaluated at compile-time. + * Callers where !size_is_constant should only be test modules, where runtime + * overheads of __kmalloc_index() can be tolerated. Also see kmalloc_slab(). */ -static __always_inline unsigned int kmalloc_index(size_t size) +static __always_inline unsigned int __kmalloc_index(size_t size, + bool size_is_constant) { if (!size) return 0; @@ -382,12 +388,17 @@ static __always_inline unsigned int kmalloc_index(size_t size) if (size <= 8 * 1024 * 1024) return 23; if (size <= 16 * 1024 * 1024) return 24; if (size <= 32 * 1024 * 1024) return 25; - if (size <= 64 * 1024 * 1024) return 26; - BUG(); + + if ((IS_ENABLED(CONFIG_CC_IS_GCC) || CONFIG_CLANG_VERSION >= 110000) + && !IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES) && size_is_constant) + BUILD_BUG_ON_MSG(1, "unexpected size in kmalloc_index()"); + else + BUG(); /* Will never be reached. Needed because the compiler may complain */ return -1; } +#define kmalloc_index(s) __kmalloc_index(s, true) #endif /* !CONFIG_SLOB */ void *__kmalloc(size_t size, gfp_t flags) __assume_kmalloc_alignment __malloc; |