Re: [PATCH net-next v2 2/2] selftests: fib_tests: Add a test case for IPv6 garbage collection

[Kui-Feng Lee <sinquersw@gmail.com>]

On 7/20/23 02:32, Paolo Abeni wrote:
> On Tue, 2023-07-18 at 11:03 -0700, Kui-Feng Lee wrote:
>> Add 10 IPv6 routes with expiration time.  Wait for a few seconds
>> to make sure they are removed correctly.
>>
>> Signed-off-by: Kui-Feng Lee <kuifeng@meta.com>
> 
> Same thing as the previous patch.
> 
>> ---
>>   tools/testing/selftests/net/fib_tests.sh | 49 +++++++++++++++++++++++-
>>   1 file changed, 48 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/testing/selftests/net/fib_tests.sh b/tools/testing/selftests/net/fib_tests.sh
>> index 35d89dfa6f11..55bc6897513a 100755
>> --- a/tools/testing/selftests/net/fib_tests.sh
>> +++ b/tools/testing/selftests/net/fib_tests.sh
>> @@ -9,7 +9,7 @@ ret=0
>>   ksft_skip=4
>>   
>>   # all tests in this script. Can be overridden with -t option
>> -TESTS="unregister down carrier nexthop suppress ipv6_notify ipv4_notify ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh"
>> +TESTS="unregister down carrier nexthop suppress ipv6_notify ipv4_notify ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh fib6_gc_test"
> 
> At this point is likely worthy splitting the above line in multiple
> ones, something alike:
> 
> TESTS="unregister down carrier nexthop suppress ipv6_notify \
> 	ipv4_notify ipv6_rt ipv4_rt ipv6_addr_metric ipv4_addr_metric
> \
> 	ipv6_route_metrics ipv4_route_metrics ipv4_route_v6_gw \
> 	rp_filter ipv4_del_addr ipv4_mangle ipv6_mangle ipv4_bcast_neigh \
> 	fib6_gc_test"
> 
>>   
>>   VERBOSE=0
>>   PAUSE_ON_FAIL=no
>> @@ -747,6 +747,52 @@ fib_notify_test()
>>   	cleanup &> /dev/null
>>   }
>>   
>> +fib6_gc_test()
>> +{
>> +	setup
>> +
>> +	echo
>> +	echo "Fib6 garbage collection test"
>> +	set -e
>> +
>> +	OLD_INTERVAL=$(sysctl -n net.ipv6.route.gc_interval)
>> +	# Check expiration of routes every 3 seconds (GC)
>> +	$NS_EXEC sysctl -wq net.ipv6.route.gc_interval=3
>> +
>> +	$IP link add dummy_10 type dummy
>> +	$IP link set dev dummy_10 up
>> +	$IP -6 address add 2001:10::1/64 dev dummy_10
>> +
>> +	for i in 0 1 2 3 4 5 6 7 8 9; do
> 		$(seq 0 9)
> 
>> +	    # Expire route after 2 seconds
>> +	    $IP -6 route add 2001:20::1$i \
>> +		via 2001:10::2 dev dummy_10 expires 2
>> +	done
>> +	N_EXP=$($IP -6 route list |grep expires|wc -l)
>> +	if [ $N_EXP -ne 10 ]; then
>> +		echo "FAIL: expected 10 routes with expires, got $N_EXP"
>> +		ret=1
>> +	else
>> +	    sleep 4
>> +	    N_EXP_s20=$($IP -6 route list |grep expires|wc -l)
>> +
>> +	    if [ $N_EXP_s20 -ne 0 ]; then
>> +		echo "FAIL: expected 0 routes with expires, got $N_EXP_s20"
>> +		ret=1
>> +	    else
>> +		ret=0
>> +	    fi
>> +	fi
> 
> Possibly also worth trying with a few K of permanent routes, and dump
> the time required in both cases?

I just realized that I don't know how to measure the time required to do 
GC without providing additional APIs or exposing numbers to procfs or 
sysfs. Do you have any idea about this?

> 
>> +
>> +	set +e
>> +
>> +	log_test $ret 0 "ipv6 route garbage collection"
>> +
>> +	sysctl -wq net.ipv6.route.gc_interval=$OLD_INTERVAL
> 
> No need to restore, gc_interval is a per namespace param specific
>>
> 
>