Re: gdb-7.11.1 - 2 weeks to go...

[Pedro Alves <palves@redhat.com>]

On 05/10/2016 05:17 PM, Joel Brobecker wrote:
> Hello everyone,
> 
> Just a quick update on this 7.11.1 release - our target release date
> is about 2 weeks away. As far as I can tell from looking at...
> 
>     https://sourceware.org/gdb/wiki/GDB_7.11_Release
> 
> ... we have 2 open PRs:
> 
>   * Bug 19828 - 7.11 regression: non-stop gdb -p <process from a
>     container>: internal error
> 
>     Looks already fixed on master, so there is a chance we might
>     be able to fix that on the branch soon.
> 

Odd, it definitely doesn't work for me on master.

This is the one that I said in the other status thread that I had
a patch for, but that it surprisingly caused regressions in
the attach-many-short-lived-threads.exp testcase.

I finally managed to find some time to stare at "set debug infrun"
logs, and wrote (I think) a full fix, here:

 [PATCH 0/6] Fix PR gdb/19828 (attach -> internal error) and attach optimizations
 https://sourceware.org/ml/gdb-patches/2016-05/msg00335.html

That's a bit ... invasive ...

I have a simpler version too, which is being carried by Fedora for
a few weeks without reports of problems:

 [PATCH/7.11.1?] Simpler fix PR gdb/19828: gdb -p <process from a container>: internal error
 https://sourceware.org/ml/gdb-patches/2016-05/msg00335.html

... though that's not as comprehensive as the bigger series.
It leaves "attach&" (background attach) broken...  I haven't heard
complaints about that so far; maybe nobody uses that command...

Another option that just occurred to me, is to apply the fuller fix
to the branch (patch #6 in the series), and disable the
attach-many-short-lived-threads.exp test in the branch?  GDB regresses
in the use case of attaching to a program that is constantly spawning
many threads in quick succession, though that's a contrived use case
to expose problems.  Probably no program in the wild is like that.
I hope.  Use cases like Go programs with tons of goroutines make me
worry a bit.

Thanks,
Pedro Alves