Re: [PATCH net] net: add RCU protection to (struct packet_type)->dev
From: Eric Dumazet <edumazet@google.com>
Date: 2026-02-02 08:47:37
On Mon, Feb 2, 2026 at 9:21 AM dongchenchen (A) [off-list ref] wrote:
quoted hunk ↗ jump to hunk
} [2] add delay to pype_seq_nextdiff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index 160dd729178f..73f5a20ef57c 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c@@ -230,11 +230,14 @@ static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos) pt = v; nxt = pt->list.next; + if (pt->dev) + mdelay(5000);
Waiting 5 seconds while holding RCU is going to fire the soft lockup detection after ~two calls to ptype_seq_next() What is the actual trace you got, and what happens if you reduce to mdelay(1000) ?
dev = rcu_dereference(pt->dev); [3] run_test.sh ./packet_type_test & cat /proc/$(pgrep -x "packet_type_test")/net/ptype &