From 44f0bd40803c0e04f1c8cd59df3c7acce783ae9c Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Fri, 4 Mar 2022 14:00:43 +0800 Subject: net: dev: use kfree_skb_reason() for enqueue_to_backlog() Replace kfree_skb() used in enqueue_to_backlog() with kfree_skb_reason(). The skb rop reason SKB_DROP_REASON_CPU_BACKLOG is introduced for the case of failing to enqueue the skb to the per CPU backlog queue. The further reason can be backlog queue full or RPS flow limition, and I think we needn't to make further distinctions. Signed-off-by: Menglong Dong Signed-off-by: David S. Miller --- include/linux/skbuff.h | 6 ++++++ include/trace/events/skb.h | 1 + net/core/dev.c | 5 ++++- 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 769d54ba2f3b..44ecbfff2b69 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -399,6 +399,12 @@ enum skb_drop_reason { * outputting (failed to enqueue to * current qdisc) */ + SKB_DROP_REASON_CPU_BACKLOG, /* failed to enqueue the skb to + * the per CPU backlog queue. This + * can be caused by backlog queue + * full (see netdev_max_backlog in + * net.rst) or RPS flow limit + */ SKB_DROP_REASON_MAX, }; diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index dbf3e2e3c1b4..3bb90ca893ae 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -47,6 +47,7 @@ EM(SKB_DROP_REASON_NEIGH_DEAD, NEIGH_DEAD) \ EM(SKB_DROP_REASON_TC_EGRESS, TC_EGRESS) \ EM(SKB_DROP_REASON_QDISC_DROP, QDISC_DROP) \ + EM(SKB_DROP_REASON_CPU_BACKLOG, CPU_BACKLOG) \ EMe(SKB_DROP_REASON_MAX, MAX) #undef EM diff --git a/net/core/dev.c b/net/core/dev.c index e2c107643ee5..460ac941a631 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4570,10 +4570,12 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) static int enqueue_to_backlog(struct sk_buff *skb, int cpu, unsigned int *qtail) { + enum skb_drop_reason reason; struct softnet_data *sd; unsigned long flags; unsigned int qlen; + reason = SKB_DROP_REASON_NOT_SPECIFIED; sd = &per_cpu(softnet_data, cpu); rps_lock_irqsave(sd, &flags); @@ -4596,13 +4598,14 @@ enqueue: napi_schedule_rps(sd); goto enqueue; } + reason = SKB_DROP_REASON_CPU_BACKLOG; drop: sd->dropped++; rps_unlock_irq_restore(sd, &flags); atomic_long_inc(&skb->dev->rx_dropped); - kfree_skb(skb); + kfree_skb_reason(skb, reason); return NET_RX_DROP; } -- cgit v1.2.3-58-ga151