base-files: upgrade: use procd to kill managed daemons

These processes are managed by procd and set to start again when killed
via the procd instance parameter "respawn" being set during init.

Example:
procd_set_param respawn 3600 1 0

When they are killed manually during sysupgrade,
they are started again in 5 seconds or less, depending on
how the "respawn" parameter is set.

Use procd through ubus to disable the instances that respawn them,
however, allow dnsmasq, netifd, and logd to restart for remote logging.

Properly closing all these processes increases free memory by about 3 MB,
which should help low memory devices upgrade without crashing.

For very low memory devices (set to 32 MB for now)
also kill dnsmasq, netifd, and logd for an additional 3 MB of free memory.

Also, bump sleep values to allow at least 10 seconds
for network interfaces and daemons
to come up after they are killed and restarted
before caches are dropped.

Signed-off-by: Michael Pratt <mcpratt@pm.me>
This commit is contained in:
Michael Pratt 2021-05-29 09:03:11 -04:00 committed by Paul Spooren
parent 5a66165cb1
commit b118aba8cb

View File

@ -123,15 +123,31 @@ kill_remaining() { # [ <signal> [ <loop> ] ]
indicate_upgrade
while read -r a b c; do
case "$a" in
MemT*) mem="$b" ;; esac
done < /proc/meminfo
[ "$mem" -gt 32768 ] && \
skip_services="dnsmasq log network"
for service in /etc/init.d/*; do
service=${service##*/}
case " $skip_services " in
*" $service "*) continue ;; esac
ubus call service delete '{ "name": "'"$service"'" }' 2>/dev/null
done
killall -9 telnetd
killall -9 dropbear
killall -9 ash
kill_remaining TERM
sleep 3
sleep 4
kill_remaining KILL 1
sleep 1
sleep 6
echo 3 > /proc/sys/vm/drop_caches