Ben Greear <gree...@candelatech.com> wrote: > I noticed my system has a hung process trying to 'rmmod nf_conntrack'. > > I've generally been doing the script that calls rmmod forever, > but only extensively tested on 5.4 kernel and earlier. > > If anyone has any ideas, please let me know. This is from 'sysrq t'. I > don't see > any hung-task splats in dmesg.
rmmod on conntrack loops forever until the active conntrack object count reaches 0. (plus a walk of the conntrack table to evict/put all entries). > I'll see if it is reproducible and if so will try > with lockdep enabled... No idea, there was a regression in 5.6, but that was fixed by the time 5.7 was released. Can't reproduce hangs with a script that injects a few dummy entries and then removes the module: added=0 add_and_rmmod() { while [ $added -lt 1000 ]; do conntrack -I -s $(($RANDOM%256)).$(($RANDOM%256)).$(($RANDOM%256)).$(($RANDOM%255+1)) \ -d $(($RANDOM%256)).$(($RANDOM%256)).$(($RANDOM%256)).$(($RANDOM%255+1)) \ --protonum 6 --timeout $(((RANDOM%120) + 240)) --state ESTABLISHED --sport $RANDOM --dport $RANDOM 2> /dev/null || break added=$((added + 1)) if [ $((added % 1000)) -eq 0 ];then echo $added fi done echo rmmod after adding $added entries conntrack -C rmmod nf_conntrack_netlink rmmod nf_conntrack } add_and_rmmod I don't see how it would make a difference, but do you have any special conntrack features enabled at run time, e.g. reliable netlink events? (If you don't know what I mean the answer is no).