[PATCH 2/3] Adjust the comment on get_order() to describe the size==0 case [ver #2]
in [Kernel]
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From: David Howells on 17 Apr 2010 10:10 Adjust the comment on get_order() to note that the result of passing a size of 0 results in an undefined value. Signed-off-by: David Howells <dhowells(a)redhat.com> --- include/asm-generic/getorder.h | 23 ++++++++++++++++++++++- 1 files changed, 22 insertions(+), 1 deletions(-) diff --git a/include/asm-generic/getorder.h b/include/asm-generic/getorder.h index 67e7245..76e9687 100644 --- a/include/asm-generic/getorder.h +++ b/include/asm-generic/getorder.h @@ -5,7 +5,28 @@ #include <linux/compiler.h> -/* Pure 2^n version of get_order */ +/** + * get_order - Determine the allocation order of a memory size + * @size: The size for which to get the order + * + * Determine the allocation order of a particular sized block of memory. This + * is on a logarithmic scale, where: + * + * 0 -> 2^0 * PAGE_SIZE and below + * 1 -> 2^1 * PAGE_SIZE to 2^0 * PAGE_SIZE + 1 + * 2 -> 2^2 * PAGE_SIZE to 2^1 * PAGE_SIZE + 1 + * 3 -> 2^3 * PAGE_SIZE to 2^2 * PAGE_SIZE + 1 + * 4 -> 2^4 * PAGE_SIZE to 2^3 * PAGE_SIZE + 1 + * ... + * + * The order returned is used to find the smallest allocation granule required + * to hold an object of the specified size. + * + * The result is undefined if the size is 0. + * + * This function may be used to initialise variables with compile time + * evaluations of constants. + */ static inline __attribute_const__ int get_order(unsigned long size) { int order; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)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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