Re: [PATCH net-next] net: flush the softnet backlog in process context
From: Eric Dumazet <hidden>
Date: 2016-08-25 14:47:50
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Thu, 2016-08-25 at 07:32 -0700, Eric Dumazet wrote:
In a future patch, we could change this so that we kick flush_all_backlogs() once for all devices, instead of one device at a time. We would not pass @dev anymore as a parameter and simply look at skb->dev->reg_state to decide to remove packets from queues in flush_backlog()
This would be something like :
diff --git a/net/core/dev.c b/net/core/dev.c
index 7feae74ca928..793ace2c600f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -4293,7 +4293,6 @@ int netif_receive_skb(struct sk_buff *skb) EXPORT_SYMBOL(netif_receive_skb); struct flush_work { - struct net_device *dev; struct work_struct work; };
@@ -4303,7 +4302,6 @@ DEFINE_PER_CPU(struct flush_work, flush_works); static void flush_backlog(struct work_struct *work) { struct flush_work *flush = container_of(work, typeof(*flush), work); - struct net_device *dev = flush->dev; struct sk_buff *skb, *tmp; struct softnet_data *sd;
@@ -4313,7 +4311,7 @@ static void flush_backlog(struct work_struct *work) local_irq_disable(); rps_lock(sd); skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) { - if (skb->dev == dev) { + if (skb->dev->reg_state == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->input_pkt_queue); kfree_skb(skb); input_queue_head_incr(sd);
@@ -4323,7 +4321,7 @@ static void flush_backlog(struct work_struct *work) local_irq_enable(); skb_queue_walk_safe(&sd->process_queue, skb, tmp) { - if (skb->dev == dev) { + if (skb->dev->reg_state == NETREG_UNREGISTERING) { __skb_unlink(skb, &sd->process_queue); kfree_skb(skb); input_queue_head_incr(sd);
@@ -4332,7 +4330,7 @@ static void flush_backlog(struct work_struct *work) local_bh_enable(); } -static void flush_all_backlogs(struct net_device *dev) +static void flush_all_backlogs(void) { unsigned int cpu;
@@ -4342,7 +4340,6 @@ static void flush_all_backlogs(struct net_device *dev) struct flush_work *flush = per_cpu_ptr(&flush_works, cpu); INIT_WORK(&flush->work, flush_backlog); - flush->dev = dev; queue_work_on(cpu, system_highpri_wq, &flush->work); }
@@ -6735,8 +6732,8 @@ static void rollback_registered_many(struct list_head *head) unlist_netdevice(dev); dev->reg_state = NETREG_UNREGISTERING; - flush_all_backlogs(dev); } + flush_all_backlogs(); synchronize_net();