[PATCH] list: use list_replace_init() instead of list_splice_init()
list_splice_init(list, head) does unneeded job if it is known that
list_empty(head) == 1. We can use list_replace_init() instead.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index 92c3d9f..0887b34 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -209,19 +209,19 @@
}
void global_flush_tlb(void)
-{
- LIST_HEAD(l);
+{
+ struct list_head l;
struct page *pg, *next;
BUG_ON(irqs_disabled());
spin_lock_irq(&cpa_lock);
- list_splice_init(&df_list, &l);
+ list_replace_init(&df_list, &l);
spin_unlock_irq(&cpa_lock);
flush_map();
list_for_each_entry_safe(pg, next, &l, lru)
__free_page(pg);
-}
+}
#ifdef CONFIG_DEBUG_PAGEALLOC
void kernel_map_pages(struct page *page, int numpages, int enable)
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 7eb36c5..465b543 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3359,12 +3359,11 @@
*/
static void blk_done_softirq(struct softirq_action *h)
{
- struct list_head *cpu_list;
- LIST_HEAD(local_list);
+ struct list_head *cpu_list, local_list;
local_irq_disable();
cpu_list = &__get_cpu_var(blk_cpu_done);
- list_splice_init(cpu_list, &local_list);
+ list_replace_init(cpu_list, &local_list);
local_irq_enable();
while (!list_empty(&local_list)) {
diff --git a/fs/aio.c b/fs/aio.c
index e41e932..8c34a62 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -777,11 +777,11 @@
static int __aio_run_iocbs(struct kioctx *ctx)
{
struct kiocb *iocb;
- LIST_HEAD(run_list);
+ struct list_head run_list;
assert_spin_locked(&ctx->ctx_lock);
- list_splice_init(&ctx->run_list, &run_list);
+ list_replace_init(&ctx->run_list, &run_list);
while (!list_empty(&run_list)) {
iocb = list_entry(run_list.next, struct kiocb,
ki_run_list);
diff --git a/kernel/timer.c b/kernel/timer.c
index 9e49dee..3bf0e9e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -419,10 +419,10 @@
spin_lock_irq(&base->lock);
while (time_after_eq(jiffies, base->timer_jiffies)) {
- struct list_head work_list = LIST_HEAD_INIT(work_list);
+ struct list_head work_list;
struct list_head *head = &work_list;
int index = base->timer_jiffies & TVR_MASK;
-
+
/*
* Cascade timers:
*/
@@ -431,8 +431,8 @@
(!cascade(base, &base->tv3, INDEX(1))) &&
!cascade(base, &base->tv4, INDEX(2)))
cascade(base, &base->tv5, INDEX(3));
- ++base->timer_jiffies;
- list_splice_init(base->tv1.vec + index, &work_list);
+ ++base->timer_jiffies;
+ list_replace_init(base->tv1.vec + index, &work_list);
while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data;
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 880fb41..740c5ab 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -531,11 +531,11 @@
static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
{
struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
- LIST_HEAD(list);
+ struct list_head list;
struct work_struct *work;
spin_lock_irq(&cwq->lock);
- list_splice_init(&cwq->worklist, &list);
+ list_replace_init(&cwq->worklist, &list);
while (!list_empty(&list)) {
printk("Taking work for %s\n", wq->name);
diff --git a/net/core/dev.c b/net/core/dev.c
index ab39fe1..195a5e9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2980,7 +2980,7 @@
static DEFINE_MUTEX(net_todo_run_mutex);
void netdev_run_todo(void)
{
- struct list_head list = LIST_HEAD_INIT(list);
+ struct list_head list;
/* Need to guard against multiple cpu's getting out of order. */
mutex_lock(&net_todo_run_mutex);
@@ -2995,9 +2995,9 @@
/* Snapshot list, allow later requests */
spin_lock(&net_todo_list_lock);
- list_splice_init(&net_todo_list, &list);
+ list_replace_init(&net_todo_list, &list);
spin_unlock(&net_todo_list_lock);
-
+
while (!list_empty(&list)) {
struct net_device *dev
= list_entry(list.next, struct net_device, todo_list);
diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index 646937c..0f37266 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -91,11 +91,10 @@
/* Must be called with the rtnl semaphore held */
void linkwatch_run_queue(void)
{
- LIST_HEAD(head);
- struct list_head *n, *next;
+ struct list_head head, *n, *next;
spin_lock_irq(&lweventlist_lock);
- list_splice_init(&lweventlist, &head);
+ list_replace_init(&lweventlist, &head);
spin_unlock_irq(&lweventlist_lock);
list_for_each_safe(n, next, &head) {