projects
/
linux-2.6-microblaze.git
/ commitdiff
commit
grep
author
committer
pickaxe
?
search:
re
summary
|
shortlog
|
log
|
commit
| commitdiff |
tree
raw
|
patch
| inline |
side by side
(parent:
add891f
)
llist: avoid extra memory read in llist_add_batch
author
Uros Bizjak
<ubizjak@gmail.com>
Mon, 17 Oct 2022 14:52:26 +0000
(16:52 +0200)
committer
Andrew Morton
<akpm@linux-foundation.org>
Fri, 18 Nov 2022 21:55:06 +0000
(13:55 -0800)
try_cmpxchg implicitly assigns old head->first value to "first" when
cmpxchg fails. There is no need to re-read the value in the loop.
Link:
https://lkml.kernel.org/r/20221017145226.4044-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
lib/llist.c
patch
|
blob
|
history
diff --git
a/lib/llist.c
b/lib/llist.c
index
7d78b73
..
6e668fa
100644
(file)
--- a/
lib/llist.c
+++ b/
lib/llist.c
@@
-26,10
+26,10
@@
bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
struct llist_head *head)
{
- struct llist_node *first;
+ struct llist_node *first
= READ_ONCE(head->first)
;
do {
- new_last->next = first
= READ_ONCE(head->first)
;
+ new_last->next = first;
} while (!try_cmpxchg(&head->first, &first, new_first));
return !first;