From 5247dbf16cee4e83eb89e4d3b87bd5e79c5d1655 Mon Sep 17 00:00:00 2001 From: Yajun Deng Date: Mon, 9 Oct 2023 19:16:33 +0800 Subject: net/core: Introduce netdev_core_stats_inc() Although there is a kfree_skb_reason() helper function that can be used to find the reason why this skb is dropped, but most callers didn't increase one of rx_dropped, tx_dropped, rx_nohandler and rx_otherhost_dropped. For the users, people are more concerned about why the dropped in ip is increasing. Introduce netdev_core_stats_inc() for trace the caller of dev_core_stats_*_inc(). Also, add __code to netdev_core_stats_alloc(), as it's called with small probability. And add noinline make sure netdev_core_stats_inc was never inlined. Signed-off-by: Yajun Deng Suggested-by: Alexander Lobakin Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 606a366cc209..02949a929e7f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10497,7 +10497,8 @@ void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64, } EXPORT_SYMBOL(netdev_stats_to_stats64); -struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev) +static __cold struct net_device_core_stats __percpu *netdev_core_stats_alloc( + struct net_device *dev) { struct net_device_core_stats __percpu *p; @@ -10510,7 +10511,23 @@ struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device /* This READ_ONCE() pairs with the cmpxchg() above */ return READ_ONCE(dev->core_stats); } -EXPORT_SYMBOL(netdev_core_stats_alloc); + +noinline void netdev_core_stats_inc(struct net_device *dev, u32 offset) +{ + /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */ + struct net_device_core_stats __percpu *p = READ_ONCE(dev->core_stats); + unsigned long __percpu *field; + + if (unlikely(!p)) { + p = netdev_core_stats_alloc(dev); + if (!p) + return; + } + + field = (__force unsigned long __percpu *)((__force void *)p + offset); + this_cpu_inc(*field); +} +EXPORT_SYMBOL_GPL(netdev_core_stats_inc); /** * dev_get_stats - get network device statistics -- cgit v1.2.3-70-g09d2