Re: Smoking gun: NetBSD 6.0.1 userland instability

[christos%astron.com@localhost (Christos Zoulas)]

In article <p06240801cd6c3845d477@[71.39.101.51]>,
Donald Lee  <MacPPC2%c.icompute.com@localhost> wrote:
>>On 13 March 2013 20:35, Donald Lee <MacPPC2%c.icompute.com@localhost> wrote:
>>> I tried another experiment.
>>>
>>> I fired up my NetBSD 5.2 system that ran my test case cleanly on the
>>> 6th of March.
>>>
>>> I was unable at that time to run my test case with 6.0 userland with a
>>> 5.2 kernel, but I didn't think of running a 6.0.1 kernel with the
>>> 5.2 system.
>>>
>>> Today I did that, swapping in the 6.0.1 stock kernel on the 5.2
>>> system, and ran my test case.  This is the same, clean, 5.2 system - same
>>> analog, same libraries, same everything.  Only the kernel is 6.0.1.
>>>
>>> It failed.
>>>
>>> I can say with confidence that this is a kernel problem, and one that
>>> was introduced in the transition to 6.0.1.  Since I have already tried the
>>> 6.1_RC1 kernel, I can also say with confidence that it is not yet
>>> fixed.
>>>
>>> This is a serious problem, because it is clearly corrupting data
>>> in some cases.
>>>
>>> I stand ready to help fix it if resources at my command can be of help.
>>
>>If you have time what might be useful would be to get a rough idea of
>>when the change was introduced. I would probably suggest the
>>following, probably with the checkout & build on the fastest machine I
>>had to hand
>>
>>- Checkout the current source tree from anoncvs at a date about midway
>>between 5.0 and 6.0
>>- run "./build.sh -m macppc tools kernel=GENERIC"
>>- If the build fails, pick another date, else test the generated version
>>- binary chop the date forward or back depending on whether the test worked :)
>>
>>That should be able to narrow down when the problem change was introduced...
>
>I fetched "cvs checkout -r netbsd-5 src -P" and built it with the "./build.sh"
>above.  The build worked.  I did the build on a clean 5.2 system.
>
>I am happy to build some kernels.  It looks like this script puts
>the kernel in:
>/usr/obj/sys/arch/macppc/compile/GENERIC/netbsd
>
>I need some help with an algorithm to "chop" the source.  I don't know
>enough about the naming conventions in cvs to select dates/tags/versions
>that I can try between 5.0 and 6.0 to find the point where it starts failing.

You ban bisect by date by:

    cvs checkout -D YYYY-MM-DD src -P
or
    cvs update -D YYYY-MM-DD -P
        

christos