diff options
| author | Eric Dumazet <edumazet@google.com> | 2025-09-09 12:19:42 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-09-14 11:35:17 -0700 |
| commit | fdae0ab67d57d480dc61e9fb45678bbdc3786711 (patch) | |
| tree | 9a45268e106c211e75c55a285db8569a9849747b /net/core/dev.c | |
| parent | 278289bcec901663868048497e36c92560bd1b14 (diff) | |
net: use NUMA drop counters for softnet_data.dropped
Hosts under DOS attack can suffer from false sharing
in enqueue_to_backlog() : atomic_inc(&sd->dropped).
This is because sd->dropped can be touched from many cpus,
possibly residing on different NUMA nodes.
Generalize the sk_drop_counters infrastucture
added in commit c51613fa276f ("net: add sk->sk_drop_counters")
and use it to replace softnet_data.dropped
with NUMA friendly softnet_data.drop_counters.
This adds 64 bytes per cpu, maybe more in the future
if we increase the number of counters (currently 2)
per 'struct numa_drop_counters'.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250909121942.1202585-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 1d1650d9ecff..2522d9d8f0e4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5248,7 +5248,7 @@ static int enqueue_to_backlog(struct sk_buff *skb, int cpu, backlog_unlock_irq_restore(sd, &flags); cpu_backlog_drop: - atomic_inc(&sd->dropped); + numa_drop_add(&sd->drop_counters, 1); bad_dev: dev_core_stats_rx_dropped_inc(skb->dev); kfree_skb_reason(skb, reason); |