[LTP] [PATCH 1/1] if-mtu-change.sh: Lower CHANGE_INTERVAL to 1

[Alexey Kodanev <alexey.kodanev@oracle.com>]

On 13.01.2021 17:07, Petr Vorel wrote:
> Hi Alexey,
> 
>> On 07.01.2021 15:02, Petr Vorel wrote:
>>> to make testing faster.
> 
>>> Tested only on netns based testing.
> 
> 
>> Hi Petr,
> 
>>> Signed-off-by: Petr Vorel <pvorel@suse.cz>
>>> ---
>>> Hi Alexey,
> 
>>> any reason why CHANGE_INTERVAL was set 5s?
> 
>> It's more or less safe time for default setup. Not sure why we don't
>> have tst_sleep in if_updown.sh though. I think this is for preventing
>> link-flap errors on the switch...
> Thanks for info.
> 
> BTW do you consider sleep $NS_DURATION as needed in
> testcases/network/stress/multicast/{packet-flood,query-flood}?
> It's before killing utils (ns-mcast_receiver, ns-udpsender),
> thus it could be removed during rewrite [1]


Hi Petr,

Do you mean "sleep $NS_DURATION" in mcast-pktfld02.sh is not needed
or something else?


> 
>> For netns it's can be set far less of cause by overriding CHANGE_INTERVAL.
> 
>>> It'd be nice to speedup the tests, which were slow even before
>>> 2d422edbf ("if-mtu-change.sh: Add max packet size detection for IPv4")
>>> which added 25% slowdown.
> 
>>> Could you please test this on two host based setup?
> 
>>> Kind regards,
>>> Petr
> 
>>>  testcases/network/stress/interface/if-mtu-change.sh | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
>>> diff --git a/testcases/network/stress/interface/if-mtu-change.sh b/testcases/network/stress/interface/if-mtu-change.sh
>>> index d2816606b..3efe00461 100755
>>> --- a/testcases/network/stress/interface/if-mtu-change.sh
>>> +++ b/testcases/network/stress/interface/if-mtu-change.sh
>>> @@ -11,7 +11,7 @@ TST_CLEANUP="do_cleanup"
>>>  . if-lib.sh
> 
>>>  # The interval of the mtu change [second]
>>> -CHANGE_INTERVAL=${CHANGE_INTERVAL:-5}
>>> +CHANGE_INTERVAL=${CHANGE_INTERVAL:-1}
> 
>>>  TST_TIMEOUT=$(((CHANGE_INTERVAL + 30) * MTU_CHANGE_TIMES))
> 
> 
>> It's better to remove TST_TIMEOUT so that CHANGE_INTERVAL can be set,
>> for example, to "100ms" for netns setup.
> How about keeping it, but consider CHANGE_INTERVAL as 1 if not a number
> (i.e. containing "ms", check with tst_is_int would be IMHO enough).
> I'll send a patch.
> 
> Kind regards,
> Petr
> 
> [1] https://urldefense.com/v3/__https://patchwork.ozlabs.org/project/ltp/list/?series=216562__;!!GqivPVa7Brio!J2u5nbibRS-k2rNR25GEw-G5q5x-tv_QzNwnbwDSga6KF3fsu3AeXSBKNL9IjIsvK6aV$ 
>