[PATCH v2 net-next 5/5] neighbour: Floor neigh_periodic_work() interval at 1s.
flat view
WARM2d
From: Kuniyuki Iwashima <kuniyu@google.com>
Date: 2026-10-13 20:58:26
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
neigh_periodic_work() reschedules tbl->gc_work with a delay of BASE_REACHABLE_TIME >> 1. neigh_table is now per-netns, and a user could hog CPU by setting BASE_REACHABLE_TIME to a small value. Unlike INTERVAL_PROBE_TIME_MS, BASE_REACHABLE_TIME is also used to compute reachable_time for NUD_REACHABLE entries. Let's floor only the GC interval at 1 second. Suggested-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/netdev/20260902143023.GA3966681@shredder/ (local) Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> --- net/core/neighbour.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index aa3da886eaab..d6e9c7c59a89 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c@@ -1042,12 +1042,12 @@ static void neigh_periodic_work(struct work_struct *work) lockdep_is_held(&tbl->lock)); } out: - /* Cycle through all hash buckets every BASE_REACHABLE_TIME/2 ticks. + /* Cycle through all hash buckets every max(HZ, BASE_REACHABLE_TIME/2) ticks. * ARP entry timeouts range from 1/2 BASE_REACHABLE_TIME to 3/2 * BASE_REACHABLE_TIME. */ queue_delayed_work(system_power_efficient_wq, &tbl->gc_work, - NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1); + max(HZ, NEIGH_VAR(&tbl->parms, BASE_REACHABLE_TIME) >> 1)); spin_unlock_bh(&tbl->lock); }
--
2.56.0.385.gd3acb90ef8-goog