[CRIU] [PATCH resend v7 00/14] net/ipv6: c/r dev/default/all conf ops

[Pavel Emelyanov]

On 04/28/2016 02:55 PM, Pavel Tikhomirov wrote:
> 
> 
> On 04/27/2016 04:20 PM, Pavel Emelyanov wrote:
>>>> He needs more fun to be happy;)
>>>   From log:
>>> 19:10:43.799:     5: FAIL: netns-dev.c:264: Option
>>> "/proc/sys/net/ipv6/conf/lo/mldv1_unsolicited_report_interval" changed
>>> from 135188171 to 135188172 (errno = 2 (No such file or directory))
>>>
>>> I think in Travis environment someone or something increments(1 to 5
>>> times in different runs) mldv1_unsolicited_report_interval and thus
>>> breaks the test(small change in value is too suspicious). But I'm not
>>> sure how to reproduce the environment locally, is there a common way?
>>>
>>> See the same behavior for test run with "--nocr" below, test fails
>>> without c/r'ing it.
>>> https://travis-ci.org/Snorch/criu/jobs/125944022
>> So, does this mean there will be v8?
> 
> CONFIG_HZ can influence mldv1_unsolicited_report_interval granularity, 
> for instance travis.ci has CONFIG_HZ=250 and thus 
> mldv1_unsolicited_report_interval is rounded up to the nearest 
> (MSEC_PER_SEC / HZ)*k which is equal to 4*k here[see kernel 
> proc_dointvec_ms_jiffies > do_proc_dointvec > 
> do_proc_dointvec_ms_jiffies_conv > msecs_to_jiffies].
> 
> So mldv1_unsolicited_report_interval and 
> mldv2_unsolicited_report_interval can have different granularity 
> depending on CONFIG_HZ.
> 
> I have question now: Do we need to restore these multicast discovery 
> report intervals precisely, or can leave what we have now? - e.g. 
> restoring with different HZ can slightly change intervals, need to fix 
> gen_conf in test to check values just after set. Personally I think it 
> is quiet safe, no one will ever mention difference in several milliseconds.

I'd restore them as-is and tuned the test to take this difference into account.

>>
>>> 21:00:54.226:     5: FAIL: netns-dev.c:264: Option
>>> "/proc/sys/net/ipv6/conf/lo/mldv1_unsolicited_report_interval" changed
>>> from 39342981 to 39342984 (errno = 2 (No such file or directory))
>>>
> 
> .
>