RFR: 8200626: Restore history for g1ConcurrentMarkThread.*

[Aleksey Shipilev]

On 04/04/2018 10:17 AM, Erik Helin wrote:
> Hi all,
> 
> this (somewhat strange) patch restores the Mercurial (hg) history for the files
> g1ConcurrentMarkThread.{hpp, inline.hpp, cpp}. This is done by re-doing the commit (but make sure to
> `hg mv`) and then performing a benign merge (the merge is not part of the webrev).
> 
> I don't think the webrev will highlight that `hg mv` was properly used, but I have verified that
> `hg log --follow src/hotspot/share/gc/g1/g1ConcurrentMarkThread.hpp` shows the entire history.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8200626
> 
> Patch:
> http://cr.openjdk.java.net/~ehelin/8200626/00/

Oh, nice trick.

The changes in src/hotspot/os/linux/os_linux.cpp seem to be the part of JDK-8199717 [1], should they
really be in webrev? I guess webrev was generated against the parent that does not include that
changeset yet? If so, I think it would be safer to generate the webrev from the merge you did
against the "real" parent head, to check that webrev did not unroll already committed changesets.
(Fun aside: we ran into the similar pitfall recently in Shenandoah!)

"hg log -G -l 5" or something would be nice to see too.

Thanks,
-Aleksey

[1] http://hg.openjdk.java.net/jdk/hs/rev/89a886b7a9cf