Files
Linux/include/linux/list_sort.h
T
George Spelvin 043b3f7b63 lib/list_sort: simplify and remove MAX_LIST_LENGTH_BITS
Rather than a fixed-size array of pending sorted runs, use the ->prev
links to keep track of things.  This reduces stack usage, eliminates
some ugly overflow handling, and reduces the code size.

Also:
* merge() no longer needs to handle NULL inputs, so simplify.
* The same applies to merge_and_restore_back_links(), which is renamed
  to the less ponderous merge_final().  (It's a static helper function,
  so we don't need a super-descriptive name; comments will do.)
* Document the actual return value requirements on the (*cmp)()
  function; some callers are already using this feature.

x86-64 code size 1086 -> 739 bytes (-347)

(Yes, I see checkpatch complaining about no space after comma in
"__attribute__((nonnull(2,3,4,5)))".  Checkpatch is wrong.)

Feedback from Rasmus Villemoes, Andy Shevchenko and Geert Uytterhoeven.

[[email protected]: remove __pure usage due to mysterious warning]
Link: http://lkml.kernel.org/r/f63c410e0ff76009c9b58e01027e751ff7fdb749.1552704200.git.lkml@sdf.org
Signed-off-by: George Spelvin <[email protected]>
Acked-by: Andrey Abramov <[email protected]>
Acked-by: Rasmus Villemoes <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Daniel Wagner <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Don Mullis <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
2019-05-14 19:52:49 -07:00

14 lines
307 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_LIST_SORT_H
#define _LINUX_LIST_SORT_H
#include <linux/types.h>
struct list_head;
__attribute__((nonnull(2,3)))
void list_sort(void *priv, struct list_head *head,
int (*cmp)(void *priv, struct list_head *a,
struct list_head *b));
#endif