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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Thu, 13 Dec 2018 01:00:49 +0000
Subject: [PATCH] do accept() in LIFO order for cache efficiency
---
include/linux/wait.h | 2 ++
kernel/sched/wait.c | 24 ++++++++++++++++++++++++
net/ipv4/inet_connection_sock.c | 2 +-
3 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 27fb99cfeb02..9a2c36d081bf 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -164,6 +164,7 @@ static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
+extern void add_wait_queue_exclusive_lifo(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
@@ -1127,6 +1128,7 @@ do { \
*/
void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
+void prepare_to_wait_exclusive_lifo(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c
index 01f5d3020589..6fb633f219c4 100644
--- a/kernel/sched/wait.c
+++ b/kernel/sched/wait.c
@@ -37,6 +37,17 @@ void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue
}
EXPORT_SYMBOL(add_wait_queue_exclusive);
+void add_wait_queue_exclusive_lifo(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
+{
+ unsigned long flags;
+
+ wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ __add_wait_queue(wq_head, wq_entry);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
+}
+EXPORT_SYMBOL(add_wait_queue_exclusive_lifo);
+
void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
{
unsigned long flags;
@@ -263,6 +274,19 @@ prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_ent
}
EXPORT_SYMBOL(prepare_to_wait_exclusive);
+void prepare_to_wait_exclusive_lifo(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state)
+{
+ unsigned long flags;
+
+ wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
+ spin_lock_irqsave(&wq_head->lock, flags);
+ if (list_empty(&wq_entry->entry))
+ __add_wait_queue(wq_head, wq_entry);
+ set_current_state(state);
+ spin_unlock_irqrestore(&wq_head->lock, flags);
+}
+EXPORT_SYMBOL(prepare_to_wait_exclusive_lifo);
+
void init_wait_entry(struct wait_queue_entry *wq_entry, int flags)
{
wq_entry->flags = flags;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index b457dd2d6c75..500fdb1bb95b 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -433,7 +433,7 @@ static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
* having to remove and re-insert us on the wait queue.
*/
for (;;) {
- prepare_to_wait_exclusive(sk_sleep(sk), &wait,
+ prepare_to_wait_exclusive_lifo(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
if (reqsk_queue_empty(&icsk->icsk_accept_queue))
--
https://clearlinux.org
|
