diff options
Diffstat (limited to 'lib/list_sort.c')
| -rw-r--r-- | lib/list_sort.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/lib/list_sort.c b/lib/list_sort.c index 0fb59e92ca2d..a310ecb7ccc0 100644 --- a/lib/list_sort.c +++ b/lib/list_sort.c @@ -1,9 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 -#include <linux/kernel.h> -#include <linux/bug.h> #include <linux/compiler.h> #include <linux/export.h> -#include <linux/string.h> #include <linux/list_sort.h> #include <linux/list.h> @@ -111,6 +108,13 @@ static void merge_final(void *priv, list_cmp_func_t cmp, struct list_head *head, * and list_sort is a stable sort, so it is not necessary to distinguish * the @a < @b and @a == @b cases. * + * The comparison function must adhere to specific mathematical properties + * to ensure correct and stable sorting: + * - Antisymmetry: cmp(@a, @b) must return the opposite sign of + * cmp(@b, @a). + * - Transitivity: if cmp(@a, @b) <= 0 and cmp(@b, @c) <= 0, then + * cmp(@a, @c) <= 0. + * * This is compatible with two styles of @cmp function: * - The traditional style which returns <0 / =0 / >0, or * - Returning a boolean 0/1. |