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From 9027d25e263c188cb9179473e02e38b3b3a7ec4d Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 12 Jul 2011 15:38:34 +0200
Subject: [PATCH 106/158] net: Use skbufhead with raw lock
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.15/older/patches-5.15.10-rt24.tar.xz
Use the rps lock as rawlock so we can keep irq-off regions. It looks low
latency. However we can't kfree() from this context therefore we defer this
to the softirq and use the tofree_queue list for it (similar to process_queue).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/skbuff.h | 7 +++++++
net/core/dev.c | 6 +++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b8c273af2910..a66f6ddbdd56 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -297,6 +297,7 @@ struct sk_buff_head {
__u32 qlen;
spinlock_t lock;
+ raw_spinlock_t raw_lock;
};
struct sk_buff;
@@ -1932,6 +1933,12 @@ static inline void skb_queue_head_init(struct sk_buff_head *list)
__skb_queue_head_init(list);
}
+static inline void skb_queue_head_init_raw(struct sk_buff_head *list)
+{
+ raw_spin_lock_init(&list->raw_lock);
+ __skb_queue_head_init(list);
+}
+
static inline void skb_queue_head_init_class(struct sk_buff_head *list,
struct lock_class_key *class)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index d4ee0b0bf635..e56e9bd1cd16 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -225,14 +225,14 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
static inline void rps_lock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_lock(&sd->input_pkt_queue.lock);
+ raw_spin_lock(&sd->input_pkt_queue.raw_lock);
#endif
}
static inline void rps_unlock(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
- spin_unlock(&sd->input_pkt_queue.lock);
+ raw_spin_unlock(&sd->input_pkt_queue.raw_lock);
#endif
}
@@ -11638,7 +11638,7 @@ static int __init net_dev_init(void)
INIT_WORK(flush, flush_backlog);
- skb_queue_head_init(&sd->input_pkt_queue);
+ skb_queue_head_init_raw(&sd->input_pkt_queue);
skb_queue_head_init(&sd->process_queue);
#ifdef CONFIG_XFRM_OFFLOAD
skb_queue_head_init(&sd->xfrm_backlog);
--
2.33.1
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