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Re: [PATCH v2] Remove signal handling for nanosleep (bug 16364)



On 11-11-2015 10:42, Adhemerval Zanella wrote:
> 
> 
> On 10-11-2015 15:48, Florian Weimer wrote:
>> On 11/10/2015 03:22 PM, Andreas Schwab wrote:
>>> Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:
>>>
>>>> That's the hole points of the previous discussion in v1 patch while
>>>> Florian also pointed this racy.  He neither I could devise a race-free
>>>> testcase to check for this issue so my questioning was if someone have
>>>> a way to remove the race or if we really should push for this test. 
>>>
>>> A racy test is as good as a non-existing test.  Everyone will ignore it.
>>
>> I disagree very strongly.  It depends on the frequency of the race, and
>> it which direction it errs (FAIL even without the bug, or PASS with the
>> bug).  Some properties are impossible to test without theoretic races.
>> It really depends on the rate of inappropriate FAILs whether such tests
>> have value or not.
> 
> Regarding to this specific test, IMHO I would prefer to not add it since
> it clearly a kernel issue which has been fixed in a long time and it is
> quite unlike to regress.  Also, any regression would be flagged a kernel
> defect and I do not see this being deployed in any kernel release.
> 
> Now regarding the racy test, I see we need to assess by case basis. I
> also I do not see strong reasoning to block this patch altogether: we
> can evaluate/push the version v3 which do not have the testcase and 
> if we decide this race-test is valuable I can prepare another patch 
> to add it.  

It appears this discussion has been stalled and to move forward at least
with the patch core discussion (nanosleep refactor), I would like to
continue discuss solely the code modification at its third version [1].

I will send another patch with the only the testcase and then we can
continue discuss if it worth or not to include possible racy testcase
in GLIBC.

[1] https://sourceware.org/ml/libc-alpha/2015-11/msg00206.html

> 
>>
>> Florian
>>


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