Confusing Mercurial history - was: Re: Hotspot segfaulting on Linux SPARC

[Stefan Karlsson]

On 2018-04-17 11:41, John Paul Adrian Glaubitz wrote:
> On 04/17/2018 11:34 AM, Stefan Karlsson wrote:
>> As I Severin said, these numbers are your local numbers and might not 
>> at all match what I have in my copy of jdk/hs. However, if we assume 
>> that they are the same, I get this:
> 
> I actually checked the revision numbers in the remote repository:
> 
>> http://hg.openjdk.java.net/jdk/hs/rev/f5a564180f37 is 46668
>> http://hg.openjdk.java.net/jdk/hs/rev/ff7b9f61209e is 46667
>> http://hg.openjdk.java.net/jdk/hs/rev/6e1b59330482 is 46931
> 
> The revision numbers match my local repository checkout.

Good. This matches what I have.

> 
>> hg log -r 'reverse(0::46931)' --graph
>>
>> o  changeset:   46931:6e1b59330482
>> |  parent:      46253:f7daf2e39cc8
>> |  user:        glaubitz
>> |  date:        Mon Aug 21 15:17:21 2017 +0200
>> |  summary:     8186433: Compiler flag -arch=sparc should not be 
>> passed on linux-sparc
>> |
>> o  changeset:   46253:f7daf2e39cc8
>> |  parent:      46250:3041c580db2a
>> |  user:        bobv
>> |  date:        Mon Aug 21 12:08:03 2017 -0400
>> |  summary:     8186115: libelf still referenced after 8172670
>>
>> Where the parent of 46931 is 46253.
>>
>> And hg log -r '46668::46931'
>>
>> gives back nothing indicating that 46668 is not a ancestor of 46931.
> 
> Ok, that's odd. I don't understand how one is supposed to perform bisecting
> then.

That means that there's nothing to bisect between 46668 and 46931. 46931 
is not built on top of 46668. They were merged at a later point. You 
need to follow the DAG when bisecting.

StefanK

> 
>> You can also find the first common ancestor of the two change sets:
>>
>> hg log -r 'ancestor(46667,46931)'
>> changeset:   45825:4fa7bd62eb84
>> parent:      45761:9ef5029b247b
>> user:        alanb
>> date:        Wed Jul 05 13:25:45 2017 +0100
>> summary:     8183503: Update hotspot tests to allow for unique test 
>> classes directory
>>
>> Can you share the SHA number for your 46668 change, and maybe the 
>> summry line as well?
> That would be:
> 
> changeset 46668:f5a564180f37
> 8182165: The header atomic_linux_sparc.inline.hpp should be named 
> atomic_linux_sparc.hpp
> 
> Adrian
>