net: reimplement softnet_data.output_queue as a FIFO queue
reimplement softnet_data.output_queue as a FIFO queue to keep the
fairness among the qdiscs rescheduled.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
----
include/linux/netdevice.h | 1 +
net/core/dev.c | 22 ++++++++++++----------
2 files changed, 13 insertions(+), 10 deletions(-)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3c5ed5f..c04ca24 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1385,6 +1385,7 @@
*/
struct softnet_data {
struct Qdisc *output_queue;
+ struct Qdisc **output_queue_tailp;
struct list_head poll_list;
struct sk_buff *completion_queue;
diff --git a/net/core/dev.c b/net/core/dev.c
index 4d43f1a..3d31491 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1557,8 +1557,9 @@
local_irq_save(flags);
sd = &__get_cpu_var(softnet_data);
- q->next_sched = sd->output_queue;
- sd->output_queue = q;
+ q->next_sched = NULL;
+ *sd->output_queue_tailp = q;
+ sd->output_queue_tailp = &q->next_sched;
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_restore(flags);
}
@@ -2529,6 +2530,7 @@
local_irq_disable();
head = sd->output_queue;
sd->output_queue = NULL;
+ sd->output_queue_tailp = &sd->output_queue;
local_irq_enable();
while (head) {
@@ -5594,7 +5596,6 @@
void *ocpu)
{
struct sk_buff **list_skb;
- struct Qdisc **list_net;
struct sk_buff *skb;
unsigned int cpu, oldcpu = (unsigned long)ocpu;
struct softnet_data *sd, *oldsd;
@@ -5615,13 +5616,13 @@
*list_skb = oldsd->completion_queue;
oldsd->completion_queue = NULL;
- /* Find end of our output_queue. */
- list_net = &sd->output_queue;
- while (*list_net)
- list_net = &(*list_net)->next_sched;
/* Append output queue from offline CPU. */
- *list_net = oldsd->output_queue;
- oldsd->output_queue = NULL;
+ if (oldsd->output_queue) {
+ *sd->output_queue_tailp = oldsd->output_queue;
+ sd->output_queue_tailp = oldsd->output_queue_tailp;
+ oldsd->output_queue = NULL;
+ oldsd->output_queue_tailp = &oldsd->output_queue;
+ }
raise_softirq_irqoff(NET_TX_SOFTIRQ);
local_irq_enable();
@@ -5851,7 +5852,8 @@
skb_queue_head_init(&sd->input_pkt_queue);
sd->completion_queue = NULL;
INIT_LIST_HEAD(&sd->poll_list);
-
+ sd->output_queue = NULL;
+ sd->output_queue_tailp = &sd->output_queue;
#ifdef CONFIG_RPS
sd->csd.func = rps_trigger_softirq;
sd->csd.info = sd;