From 1b5c5493e3e68181be344cb51bf9df192d05ffc2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 13 Jun 2016 20:21:50 -0700 Subject: net_sched: add the ability to defer skb freeing qdisc are changed under RTNL protection and often while blocking BH and root qdisc spinlock. When lots of skbs need to be dropped, we free them under these locks causing TX/RX freezes, and more generally latency spikes. This commit adds rtnl_kfree_skbs(), used to queue skbs for deferred freeing. Actual freeing happens right after RTNL is released, with appropriate scheduling points. rtnl_qdisc_drop() can also be used in place of disc_drop() when RTNL is held. qdisc_reset_queue() and __qdisc_reset_queue() get the new behavior, so standard qdiscs like pfifo, pfifo_fast... have their ->reset() method automatically handled. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'net/core') diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index d69c4644f8f2..eb49ca24274a 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -71,9 +71,31 @@ void rtnl_lock(void) } EXPORT_SYMBOL(rtnl_lock); +static struct sk_buff *defer_kfree_skb_list; +void rtnl_kfree_skbs(struct sk_buff *head, struct sk_buff *tail) +{ + if (head && tail) { + tail->next = defer_kfree_skb_list; + defer_kfree_skb_list = head; + } +} +EXPORT_SYMBOL(rtnl_kfree_skbs); + void __rtnl_unlock(void) { + struct sk_buff *head = defer_kfree_skb_list; + + defer_kfree_skb_list = NULL; + mutex_unlock(&rtnl_mutex); + + while (head) { + struct sk_buff *next = head->next; + + kfree_skb(head); + cond_resched(); + head = next; + } } void rtnl_unlock(void) -- cgit v1.2.3