Florian Westphal <fw@xxxxxxxxx> wrote: > Ulrich reports soft lockup with following (shortened) callchain: > > NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! > __netif_receive_skb_core+0x6e4/0x774 > process_backlog+0x94/0x160 > net_rx_action+0x88/0x178 > call_do_softirq+0x24/0x3c > do_softirq+0x54/0x6c > __local_bh_enable_ip+0x7c/0xbc > nf_ct_iterate_cleanup+0x11c/0x22c [nf_conntrack] > masq_inet_event+0x20/0x30 [nf_nat_masquerade_ipv6] > atomic_notifier_call_chain+0x1c/0x2c > ipv6_del_addr+0x1bc/0x220 [ipv6] > > Problem is that nf_ct_iterate_cleanup can run for a very long time > since it can be interrupted by softirq processing. > Moreover, atomic_notifier_call_chain runs with rcu readlock held. Ulrich just reported another softlockup even with this patch applied. One explanation would be non-matching iter(), in this case get_next_corpse can take forever since it will walk the entire conntrack table, rendering the cond_resched moot. A V2 patch will be coming to also add a lock break + resched to get_next_corpse. I'll mark it as 'changes requested' in patchwork. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
